Investigator In Charge (IIC): Salazar, Fabian
The National Transportation Safety Board traveled to the scene of this accident.
Additional Participating Entities:
Craig F. Karel; Federal Aviation Administration / Flight Standards District Office; Boise, Idaho
Textron Aviation; Wichita, Kansas
Location: Heyburn, Idaho
Accident Number: WPR22FA151
Date and Time: April 13, 2022, 08:32 Local
Registration: N928JP
Aircraft: Cessna 208B
Injuries: 1 Fatal
Flight Conducted Under: Part 135: Air taxi & commuter - Non-scheduled
On April 13, 2022, about 0832 mountain daylight time, a Cessna 208B Grand Caravan, N928JP, was substantially damaged when it was involved in an accident near Heyburn, Idaho. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulation Part 135 cargo flight. According to the operator, the pilot was transporting cargo on an instrument flight rules flight from the Salt Lake City International Airport (SLC), Salt Lake City, Utah, to the Burley Municipal Airport (BYI), Burley, Idaho.
A review of air traffic control (ATC) communication with the pilot revealed the approach controller issued the pilot the current altimeter setting and verified that the pilot had the current weather and notices to airmen reports for BYI. Subsequently, the controller cleared the pilot for the RNAV runway 20 approach via the MALTT transition at BYI. The pilot reported passing the initial approach fix, and about 4 minutes later reported a missed approach. The controller then instructed the pilot to execute the published missed approached and to report established [in the hold] at IREME, and to expect the same approach.
After the pilot report established at IREME, the controller cleared the pilot for the approach. About 1 minute later, the controller asked the pilot if she had crossed the initial approach fix. The pilot initially replied negative, then subsequently replied that she had crossed the fix. The controller then approved a change to BYI advisory frequency.
Video footage recovered from a security camera located on a processing plant revealed a view of the rooftop of the processing plant, along with a smokestack supported by steel framework on the roof. Snow was observed falling. About 0832:25, the airplane came into view in a wings-level, nose-high descent. The airplane subsequently struck the smokestack and fell to the rooftop.
According to a witness, located about one quarter mile away, he first heard, then observed the airplane descend out of the clouds then immediately went into a steam cloud, which was produced from a set of six smokestacks located on the same roof. The witness heard the engine increase in sound and saw the nose lift shortly before the airplane struck the smokestack and descend to the rooftop.
The airplane came to rest on its right side. Both wings, the propeller assembly, belly pod, and the nose wheel separated from the fuselage. All major components of the airplane remained on the rooftop. First responders recovered about 40 gallons of jet fuel which had spilled from both wings.
A special automated weather report for BYI about the time of the accident reported 1 mile visibility in light snow and mist, broken layer at 2,300 ft above ground level (agl), overcast at 2,800 ft agl, temperature -3°C, dew point temperature -5°C, barometric pressure 29.96 inches of mercury. An Airmen’s Meteorological Information (AIRMET) advisory was active for icing and mountain obscurations for areas that included BYI.
The airplane was recovered to a secure facility for further examination.
Aircraft and Owner/Operator Information
Aircraft Make: Cessna
Registration: N928JP
Model/Series: 208B
Aircraft Category: Airplane
Amateur Built:
Operator:
Operating Certificate(s) Held: Commuter air carrier (135)
Operator Designator Code:
Meteorological Information and Flight Plan
Conditions at Accident Site: IMC
Condition of Light: Day
Observation Facility, Elevation: KBYI,4143 ft msl
Observation Time: 08:10 Local
Distance from Accident Site: 1 Nautical Miles
Temperature/Dew Point: -3°C /-5°C
Lowest Cloud Condition:
Wind Speed/Gusts, Direction: 8 knots / , 190°
Lowest Ceiling: Broken / 2300 ft AGL
Visibility: 1 miles
Altimeter Setting: 29.96 inches Hg
Type of Flight Plan Filed: IFR
Departure Point: Salt Lake City, UT (SLC)
Destination: Burley, ID (BYI)
Wreckage and Impact Information
Crew Injuries: 1 Fatal
Aircraft Damage: Substantial
Passenger Injuries:
Aircraft Fire: None
Ground Injuries:
Aircraft Explosion: None
Total Injuries: 1 Fatal
Latitude, Longitude: 42.551433,-113.75969
Those who may have information that might be relevant to the National Transportation Safety Board (NTSB) investigation may contact them by email witness@ntsb.gov, and any friends and family who want to contact investigators about the accident should email assistance@ntsb.gov. You can also call the NTSB Response Operations Center at 844-373-9922 or 202-314-6290.
Chelsea Brittney Infanger
January 31, 1992 - April 13, 2022
Chelsea Brittney Infanger, returned to her Heavenly Father unexpectedly on April 13, 2022. Brittney was born on January 31, 1992 in Salmon, Idaho to Sharon and Jim Bob Infanger, their fifth child and second daughter. Although Brittney passed away young, her adventurous, loving spirit led to an abundant life.
In high school, she competed on basketball, track, volleyball, and dance teams, served as a page in the Idaho State Legislature, was voted to Senior Class President, and graduated from Salmon High School in 2010 as a Valedictorian with a 4.0 GPA. Following high school, Brittney received a prestigious internship with NBC International, working in their hospitality program for the 2012 London Olympics. Brittney went on to graduate from Utah State University with a degree in Finance in 2018.
Brittney explored many hobbies throughout her life, including piano, athletics, fishing, and hunting. However, Brittney’s favorite thing of all was flying. She received her private flying license in high school. Even after receiving her bachelor’s degree, all Brittney wanted to do was fly. She went on to graduate from ATP Flight School in Mesa, Arizona in 2019.
After graduating from ATP, Brittney was a flight instructor at Aero guard, Gem Air, and privately in Salmon, Idaho, and received various flight licenses, including commercial, instrument, multiengine, CFI, CFII, MEI, tailwheel, and seaplane. She was also trained in aerobatic flying, advanced spin training, and upset recovery training. She loved flying the Idaho backcountry while working for Gem Air as well as flying UPS routes in Idaho and Utah.
Brittney often told those who had the privilege of flying with her that she never felt closer to heaven than she did when flying. Once, when flying with her sister, they looked out at the mountains, trees, and clouds, marveling at the beauty. “How could anyone be up here, see God’s creation, and doubt His love?” she had asked. Her last post on social media read “I’ve been flying so much lately I think I might be growing wings.”
Her love for flying was only surpassed by the love she had for her family and friends. Brittney had a special connection with her siblings and their children. She loved spending time with her father, who taught her to play basketball, hunt, fish, and fly. The relationship Brittney had with her mother was truly like no other. Their bond was unbreakable, and their most fun times were spent together, especially when traveling the world.
Brittney was a member of the Church of Jesus Christ of Latter-day Saints and served a mission in Birmingham, England from 2015-2017. She was always striving to be an example of Christ and share His love with others.
Brittney lived life to its fullest. She traveled, she laughed, she loved. She was outgoing, welcoming, and Christlike. Brittney’s spirit could be felt by all who knew her. She had a special gift for making everyone she met feel important, and her smile lit up every room. She not only saw the best in people, she brought out the best in people.
When you think of Brittney, celebrate the memories you shared with her. Remember to embrace and treasure every moment, just as she did. Our beautiful and beloved daughter, granddaughter, sister, niece, cousin and friend will be missed more than words can express, but she will be in all our hearts until we meet again.
Brittney was preceded in death by her paternal and maternal grandparents, Vera and Ray Infanger and Idell and Don Weeks, and her brother, Earl James “E.J.” Infanger. Brittney is survived by her parents, Sharon and Jim Bob Infanger, her siblings, Craig Infanger (Daria); Emily Goodrich (Robert); Branden Infanger (Annie); Jayden Infanger; Erica Hill (Taylor); Adrienne Rochleau (Chris); and her loving nieces, nephews, aunts, uncles and cousins.
Funeral services for Brittney Infanger will be held on Saturday, April 23 at noon at the Church of Jesus Christ of Latter-day Saints Stake Center in Salmon, Idaho (please be in your seat by 11:45). Visitation will begin at 10:30 the morning of the funeral. Funeral services will also be live streamed at bit.ly/brittneyinfanger. In lieu of flowers, the Infanger family is welcoming donations for a scholarship fund in Brittney’s honor. Donations can be dropped off or mailed to Bill Allen Accounting at 533 Main St., Salmon, Idaho 83467.
Looking at flightaware data, the pilot made two approaches on RNAV RWY 20. The MDA is 4560 with a TDZE of 4152; so 408 above with a requirement of 1 mile visibility. First approach got down to 4375 which is 185 below MDA. Second time around, the airplane's last data is 4150 (ground elevation) with an groundspeed of 80 knots. Vertical rate was approximately 900 fpm at last point and it appears it hit some silos at a food plant. Previous day, the aircraft had to divert to Twin Falls. Weather, 20 minutes before incident, was 1 mile, light snow, broken at 2300, overcast at 2800.
ReplyDeleteMETAR:
DeleteKBYI 131440Z AUTO 21008KT 2 1/2SM -SN BKN030 OVC047 M03/M06 A2997
KBYI 131410Z AUTO 19008KT 1SM -SN BR BKN023 OVC028 M03/M05 A2996
Track:
https://flightaware.com/live/flight/N928JP/history/20220413/1300Z/KSLC/KBYI
A lot of conjecture in this comment, I have over 200 instrument approaches to this airport (of course all have been at minimums :-)), the silos don't come in to play, neither do the cooling towers, it is a tricky approach with a lot of thermal issues from the potato plant and river and roadways but nothing a 1500+ hour pilot can't handle. I wouldn't start speculating that they hit the silos, without proof, because those of us who live there see no indication that the silos or cooling towers were touched.
DeleteAs any pilot knows, the altitudes reported by FlightAware are uncorrected pressure altitudes and do not reflect the corrected indicated barometric altitude that pilots reference for assigned altitudes, MDA, etc. The altimeter at the destination airport was 29.97, so the pressure altitude correction would be +50 feet, that combined with FlightAware's rounding error and a +/- 75 foot allowed altimeter variance means the pilot may not have busted the MDA on the first approach as was implied. In general, FlightAware is not intended to be an accurate indication of aircraft altitudes and positions for forensic purposes, so armchair investigators would do well not to draw detailed conclusions from FA data.
DeleteI see no conjecture from the original post; only data from flightaware. What people want to see is their own conjecture.
DeleteFlying is 90% mental, just like golf.
DeleteJust be honest you go below MIN at uncontrolled who would know about it?
DeleteIt may be tempting to go below the MDA before the VDP at an uncontrolled field, but then again, why do it and risk death? Oh, right--where IS the VDP on this approach? Gotta crank one out.
DeleteADSB data and Airport Surveillance Cameras are God Sends for looking into aircraft mishaps such as these. If the ADSB data is accurate, it will reveal the causal factors apparent in this tragedy.
DeleteApparently the mail must get through, despite the automated voice telling you "Minimums" and you don't have the runway.
ReplyDeleteFirst, it is sad that we lost such a wonderful young lady who had nothing but love in her heart and who served others selflessly.
ReplyDeleteTake this for what it is - some old pilot's opinion. It's not the answers that friends and family will want.
The Caravans of today, even one 9 years old, are equipped with the G1000 avionics system, really about a dozen computers. There is a LOT of detail logged in the G1000 system onboard these aircraft. While they are not flight data recorders in the normal sense, in a crash with no fire they can provide more than enough data for the NTSB to reconstruct what the aircraft was doing and was being presented to the pilot. It doesn't provide the external factors such as bird strikes or the flight deck conversation to know the human factors. The airport instrumentation tells a story regarding what is happening at the airport. There may also be weather equipment at that plant and it may have logging capability. Hopefully that, and possibly cameras at the airport or in the vicinity of the airport can provide some information though most are not pointed towards the sky.
Pilots that fly this route regularly will be intimately familiar with the obstacles and may even stay a little high and err to stay slightly on the right side of the approach or keep the diamonds centered and follow the flight director. Flying a stabilized approach the plant and the runway should have been visible about a mile out. At the processing plant she is less than 1/2 mile out and should have the runway in sight and been scanning between the avionics and outside. That's not much time at 90-100kts, about 20 seconds from the time the aircraft hits decision altitude 500 feet above the ground to the time it is paralell to the stacks.
On a 3 degree glidpath to LPV minimums you are 54 feet above the normal threshold. KBYI has a 3.7 degree glidepath for obstacles, including the plant and the railroad brige, which would put her at 66.7 feet over the threshold and about 108 feet over the end of the displaced threshold. Carrying that angle across the river and over to the factory she should have been approximately 230 feet above the ground and 160 feet above those stacks. Additionally, the aircraft should have been approximately 100 feet to the right of the stacks if the needles/diamonds are centered and on the approach path. The stacks are about 2050 feet from the runway end as marked by the threshold bar before the "piano keys" and not including the displaced threshold. Additionally, with the needles centered she would have been 100 feet to the right of the stacks on a normal GPS approach.
Looking at the ADS-B track on the missed it shows her at 6950 which should be coming from the GPS. Assuming the aircraft is indicating 7000 on the altimeter, when she went missed and flew the published missed approach, she was 50 feet lower than expected. Even reading 50 feet low she should have been 110 feet above that chimney/stack. That having been said, in the post-crash video it appears that the aircraft may have clipped that safety cage about 30 feet below the top of the chimney/stack.
As for the plant, since that large chimney is less than 200 feet (14 CFR 77), any lighting would have been voluntary (AC70/7460-1K 01FEB2007). It would be interesting to know if the FAA recommended to the plant that they voluntarily add a lighting system to that tall chimney or stack. I can't tell, from Google Maps, if there is a light for that chimney. There is something definitely sticking above the top of the chimney on a yellow pole coming from the cage.
While it will be interesting to see if the GPS or WAAS signal was degraded for the GPS RWY 20 approach, the pilot should have been in visual conditions.
/ME
A few corrections:
Delete1. G1000 avionics can log a lot of data if and only if you have a formatted SD card in the top slot of the MFD. Not every pilot/operator does so, especially if its not required by the SOP.
2. The altitudes Flightaware shows are the uncorrected pressure altitudes reported by the aircraft's ADS-B transmitter. To get the actual indicated altitude, you need to correct it with the local altimeter setting. The altimeter setting at the destination airport was 29.97, so the pressure altitude correction would be +50 feet, which puts the aircraft right at the expected altitude of 7,000 feet, not 50 feet too low as you surmised.
3. ADS-B does report a GPS altitude (although Flightaware does not show it), however this altitude is height above the ellipsoid, which can vary from true MSL by up to 150 feet depending where in the country you are, and this will also be different than the corrected barometric altitude shown on the pilot's altimeter due to a variety of factors that I won't go into here.
Great corrections/analysis!
DeleteAnonymous said "On a 3 degree glidpath to LPV minimums you are 54 feet above the normal threshold."
DeleteI'm not sure why you are mentioning LPV minimums, because the RNAV (GPS) RWY 20 approach into BYI is just an LNAV category approach, not LPV. There is no "glidepath", "decision altitude", "needles" (plural), or any sort of vertical guidance at all. You just get one needle for lateral guidance, some step down altitude restrictions and an MDA. The 3.75 degrees shown on the approach plate is the descent angle from the FAF to the TCH. Confusingly, the approach plate says "VGSI and descent angles not coincident", but runway 20 does not have any sort of VGSI at all! You are on your own to figure out an appropriate descent angle to keep you clear of the numerous hazardous obstacles on final.
One more correction, 230 feet above the ground isn't 160 feet above the stack. Top of the stack that was hit is 100 feet AGL.
DeleteThirty feet is not a big change in your analysis, but after verifying the stack is #16-036731 in the obstruction database, true height of 100 feet is the verified data. (see threads further below)
It may show in this picture where the aircraft impacted the yellow ladder apparatus and dented the smokestack. However, I do not live out there and haven't seen the stack in person.
ReplyDeletehttps://gray-kmvt-prod.cdn.arcpublishing.com/resizer/Z9XA94vRdq5ABRdEofwGJeK0tGE=/1200x675/smart/filters:quality(85)/cloudfront-us-east-1.images.arcpublishing.com/gray/JNAC4GVPRBC7RHHQSIO3P2WAEY.JPG
Anonymous Said: "I wouldn't start speculating that they hit the silos, without proof, because those of us who live there see no indication that the silos or cooling towers were touched."
No question that the yellow ladder has been displaced. Notice how the un-guarded ladder portion below the guarded portion of the ladder above the mid-deck platform is angled as a result of the top of the caged portion of the upper ladder having been pushed to the left.
DeletePre-accident street view shows ladder system was straight:
https://goo.gl/maps/tPdJ43wFNooD2PUX8
Viewing from ground level by opening and swinging around in these views provides additional context:
DeleteStreet view looking at RW20 centerline from 7th street that can be spun around to face the other way:
https://goo.gl/maps/Mv4KYwWvVj7FTW2s5
Street view showing another side view of stacks, single stack that is the subject of ladder discussion is at the far right:
https://goo.gl/maps/Jfy1KdpC4Yfyiwu77
^^ Corrected link for pre-accident street view that shows yellow ladder system was straight:
Deletehttps://goo.gl/maps/CqTD5vsKPo3e2cK99
I drove by there this afternoon and there is a stack to the right of the wreckage that is dented and the ladder is damaged. I estimated that the top of the stack is maybe 150 AGL feet and about 50-60 feet above the building.
DeleteYour top of stack AGL estimate is off somehow - the building roof would have to be 90 feet high.
DeleteNo problem to figure out from the street view image, using the height of the red frame's upper platform yellow guardrail as a measuring reference for the stack and truck bay door openings to figure roof elevation.
The stack rises above the roof surface by approximately 20 multiples of the guardrail height. Osha's 42 inch guardrail standard x 20 comes out to 70 feet.
This was the image used:
https://goo.gl/maps/CqTD5vsKPo3e2cK99
Door opening height to clear semi trucks are 14 feet. Looking at the #1,2 & 3 truck bays on the tater building, the roof height looks to be about 26 feet.
This was the image used showing the truck bays:
https://goo.gl/maps/xinz7GVPnjkDvJUp6
The height AGL to top of stack (if the stack has not been changed from what is seen in the street view image) would be about 70 + 26, making it roughly 100 feet instead of 150.
Stack is in FAA obstruction database as 100 feet AGL.
DeleteFound the stack in the 16-ID.dat obstruction database file of December 28, 2021 from:
https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dof/
Data record decodes to 100' AGL, with red light "R":
16-036731 O US ID HEYBURN 42 33 05.92N 113 45 34.15W STACK 1 00100 04256 R 4 D P 2016ANM01617OE A 2017285
You can download and unzip the Idaho file or just use the data format info starting on readme pdf page 5 to decode the string:
https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dof/media/DOF_README_09-03-2019.pdf
Location coordinates 42° 33' 5.92"N and 113° 45' 34.15"W convert to 42.551644, -113.759486 decimal using:
https://www.fcc.gov/media/radio/dms-decimal
Re-verifying by map-pinning the converted coordinates:
http://maps.google.com/maps?t=k&q=loc:42.551644+-113.759486
That is the stack...
Here's what's left of the stack in question, at the 2:24 point in the video.
Deletehttps://youtu.be/aRN3RJaW618
I have done this approach alot and I don't bother with 20 when burley is at minimums or fact that I can't circle to land 24 . 24 much safer and longer runway which I feel more comfortable with.
ReplyDeleteAgreed. Same.
DeleteClose up photos clearly show that the tall stack with the yellow ladder was hit. That building and stack was constructed relatively recently. WHY?
ReplyDeleteLooked for photos of how "recently" roof stacks existed there. Stacks on the roof at the collision location were photographed there in a 2018 Town News article about the plant.
DeleteStreet view images can be compared to the 2018 article photo that captured the six-stack array at the same height and in-line on the roof along the flight path just beyond the one that was struck.
Here is street view of the one hit AND the group of six:
https://goo.gl/maps/WeoRjbGZmZXoMTCc7
This photo of the six is from the 2018 Town News article:
https://bloximages.chicago2.vip.townnews.com/magicvalley.com/content/tncms/assets/v3/editorial/b/c2/bc27f097-bd84-53a5-aeb6-2da8c0892dd7/5a7a51136f27f.image.jpg?resize=785%2C500
The 2018 Town News article itself:
https://magicvalley.com/gem-state-processing-provides-jobs-inclusive-plant-culture/article_94ba4fdd-39fa-5288-9562-597369987652.html
Those stacks have been on the roof at least four years. Maybe you thought they were recent because the overhead photo shown on google map imaging is not as recent as street view or the Town News article photos and the red metal structure and yellow ladder wasn't there when the outdated overhead image was taken.
And red frames/ladders would have been added solely so the personnel could go up easily to do stack sampling for environmental compliance, suggesting that the stacks existed by themselves for many years, before the exit point sampling requirement began.
DeleteI'd argue a much better and less rhetorical question is what was an airplane doing at that altitude in IMC conditions? The crash wasn't a result of a tower appearing out of nowhere, but an airplane appearing where it shouldn't be.
DeletePlant has more political clout then an airport that is why it was built.
DeleteI believe the stack in question WAS added relatively recently (it is NOT one of the six clustered together, is was by itself on a different part of the roof.
DeleteWhy was the pilot of the Caravan 75-80' agl, only 2500' from the threshold? This was not the fault of any tower on the processing plant.
DeleteIt's very possible she could see the runway but wasn't seeing the smoke stack for various reasons
ReplyDeletePerhaps was not following the flight director and passing weather unexpectedly started dropping heavier mist and snow just long enough to obscure visual.
DeleteHere is the NEXRAD weather playback for the 1400 to 1500Z period, with BYI's location marked. You can use the controls at the top to stop at 14:31:00 and have a look:
http://weather.rap.ucar.edu/radar/displayRad.php?icao=KSFX&prod=CREF&bkgr=color&endDate=20220413&endTime=15&duration=1
(Link will show that look-back until seven days from 4/13, so copy images before they are no longer accessible if of interest.)
Did you notice the color of the smoke stack? Also the color of the building itself? Would have blended right in with the white sky. She must have had sight of the runway lights which allowed her to descend below MDA but didn't see the smokestack. It can be hard to determine your altitude based on just the runway light, she probably had very few references visually to go by. Also no PAPI on that runway so no way to determine her glidepath without visual references.
DeleteNot sure if runway lights would be on, since it was 8:32 AM MDT with sunrise an hour and a half earlier at 6:56 AM. The obstacle database shows a red light on the stack, but photocell would likely keep it off after sunrise.
DeleteWatch the Kameraone.com scene video in comments further down, it helps visualize snow fall effects that were still intermittently occurring after ladder trucks arrived.
So using the very unscientific method of looking at the Foreflight 3D airport view to visualize a KBYI runway 30 approach at a standard 3.0 degree descent angle, it is clear that those stacks are pretty much directly in your path.
ReplyDeletehttps://imgur.com/a/7FTQ82n
The runway has no VASI, PAPI or other visual glidepath aid to indicate that you are dangerously close to hitting those obstacles. If the stacks are putting out a bunch of smoke and steam, I can see how you could easily hit them despite them having red anti-collision lighting (according to the obstacle database at least.)
You probably meant RWY 20. There is no RWY 30 at KBYI.
DeleteAdditionally, someone posted where the chimney was located, about 100 feet to the left. You make a good point regarding the stacks based upon Google maps. My guess is in the cold they are creating their own little obscuring weather system. As she descended she may have lost sight of the runway. ...and should have gone around or made sure the diamonds were centered.
https://flightaware.com/live/flight/N928JP/history/20220413/1300Z/KSLC/KBYI/tracklog
Both of those approaches aren't as stabilized so my guess is that she was experiencing a lot of turbulence though the winds were fairly light (8kts) and practically straight down the runway (190).
Yes, sorry about the typo, runway 20, not 30. The imgur caption has the correct runway number.
DeleteYes exactly. I can see someone trying to land on the roof of that factory, confusing it for the extended threshold of the runway in the bad conditions. Gray light is the worst, and that sort of snow just is impossible to see through clearly.
DeleteThink logically: If the roof could be seen and descended toward as if it was runway, the Snake river and railroad bridge would be expected to occupy that same view.
DeleteNon-credible to believe roof was perceived as runway with continuation all the way to impact by a pilot expecting the river to lay across the approach end of the runway as it had always been in every previous landing there.
Looking at where the airspeed decayed is there any possibility of a flameout?
ReplyDeleteIgniters should have been on continuous.
I have never heard of a Caravan having enough turbulence to unport the fuel and cause a flameout.
Thoughts?
If she was trading altitude to maintain airspeed after a flameout, seems like it would be important to get an idea of what minimum airspeed should be maintained, knowing that the stacks were ahead.
DeleteThe TL:DR for the details shown below is that she was holding 89/88 knots airspeed in the 30 seconds or so before stack impact compared to 96 knots across the tater plant on 4 April's RW20 approach.
If you were the C208 pilot and had adequate visual of the ground so near, would you have shallowed the altitude trade off and accepted a lower airspeed than 88 knots to squeak over the tater plant?
------ Backup info ------
To provide a reference on judging whether airspeed decayed in a manner different from what she would have flown normally (acknowledging the sink rates reported in the data), compare speeds by looking at the last two captured data points as she turned across the tater plant during the uneventful 4 April approach to RW20:
Using track log data from:
https://flightaware.com/live/flight/N928JP/history/20220404/1318Z/KSLC/KBYI
Mon 09:52:44 AM 42.5539 -113.7523 ← 271° 83 96 4,675 -385
Map pinned location of that data point:
http://maps.google.com/maps?t=k&q=loc:42.5539+-113.7523
Mon 09:53:05 AM 42.5501 -113.7611 ↙ 219° 87 100 4,475 -571
Map pinned location of that data point:
http://maps.google.com/maps?t=k&q=loc:42.5501+-113.7611
(The 42.5501+-113.7611 location is approx 670 feet closer to the airfield than the struck stack.)
ADS-B shows ground speed, of course. The April 4 METAR headwind of 9 knots at the time is added to the ground speeds, making airspeed 96 knots in the 09:53:05 AM April 4 data point (note that the arcing track getting from the 09:52:44 to the 09:53:05 data point is actually a further distance than straight line, making the true airspeed slightly higher):
April 4 METARS (from mesonet.agron.iastate.edu):
KBYI 041350Z AUTO 22009KT 10SM CLR 04/M08 A2975
KBYI 041353Z AUTO 23009KT 10SM CLR 05/M08 A2975
For the accident day, the April 13 METAR headwind of 8 knots at the time is added to the ADS-B reported ground speeds.
At 21 seconds before reaching the tater building's edge and 300 feet higher, airspeed was 81 + 8 = 89 knots:
Wed 10:32:04 AM 42.5578 -113.7532 ↙ 216° 81 93 4,450 -750
http://maps.google.com/maps?t=k&q=loc:42.5578+-113.7532
At reaching the edge of the building, 80 + 8 = 88 knots:
Wed 10:32:25 AM 42.5520 -113.7592 ↙ 217° 80 92 4,150 -857
http://maps.google.com/maps?t=k&q=loc:42.5520+-113.7592
Checking Notams for BYI, no mention of towers or obstacles with the exeception of a tower 30nm away. Agree that the silos and chimney were not a factor; I did a Google maps street view and nothing is very high on that property. For whatever reason, she was below MDA, and I'm guessing they'll find fuel starvation. Whatever the case, I can't imagine the pain her family is going through.
ReplyDeleteThe A/FD mentions the threshold is displayed 305 feet due to the stack. Don't forget that NOTAMs should not be permanent notations but rather temporary fixes or transient notifications until the appropriate official guidance can be updated.
DeleteFrom an Engineers perspective, looking at Google Earth Pro, the runway centerline runs within 5 feet or so from the stack that looks to have been struck by the left wing of the aircraft.
ReplyDeleteRecent Google Map views show a very sturdy tubular platform and ladder system was added around the stack sometime after 2016. The ladder going to the top of the stack is in three sections going to three platforms. There is a platform after the first section of ladder where you have to walk over to get to the second section, so that is not a broken ladder, it is the design in the ladder system. From the second platform level, the ladder going to the top level platform is missing and you can see a section of stack that appears damaged just below the top platform.
The plane is resting upside down pointing towards the probable point of impact about 90 feet away, with about a 190 degree counter clockwise rotation and flip supporting the left wing strike probably. The left wing shows most of the damage where it connects to the fuselage. During the flip, the right horizontal stabilizer contacted something, most likely the roof, but not with much force.
The "what happened" seems evident, but "why it happened" is unknown and will likely remain that way. Prayers for this family and those impacted by this tragedy.
The entire left wing leading edge from tip to the square-cornered root is unblemished when you look at the 00:07 to 00:12 second close-up view in the Kameraone scene video. Left wing may have been inertia-separated.
DeleteThe wrecked engine bay is visible to the right of the flipped forward pilot's door and the PT-6 air plenum is identifiable in that torn open forward bay wreckage.
Kameraone.com's scene video:
https://www.kameraone.com/trending-stories/#7568616
For reference, a C208B PT-6 air plenum example photo:
Deletehttps://media.sandhills.com/img.axd?id=7257643989&wid=4326165471&rwl=False&p=&ext=&w=0&h=0&t=&lp=&c=True&wt=False&sz=Max&rt=0&checksum=MwQ%2b3%2fmnuLw%2bzq2hh%2ftYM0KEexS1%2fpTBK5zoSVQPYb8%3d
Active snow fall is captured after the 14 second mark in this video of the crash scene. Notice the visibility when looking at a distance horizontally in the 25 to 28 and 44 to 47 second portions of the video.
ReplyDeleteSeems possible that dynamic weather conditions prior to what is captured in the video could have hampered visual obstacle recognition approaching the plant.
Kameraone.com's scene video:
https://www.kameraone.com/trending-stories/#7568616
See also sky condition in this News2 photo:
https://idahonews.com/resources/media/a208fbff-8980-455e-84de-b4b81621fe20-medium16x9_KMVT_PHoto.JPG?1649892680255
very sad. freight dogs fly to some airports that are questionable at best with shaky non precision step down approaches with no glideslope. folks in charge of choosing these airports are not always aware of the dangers of choosing these airports for daily scheduled flights in all weather conditions. they should be held to some degree of accountability for these life and death decisions they make to put these mostly inexperienced pilots in life or death situations. do these decision makers even know the difference between a precision and non precision approach? i suspect many if not most do not. they should be required to fly out to these locations on days like this once in a while for the education needed to make safer decisions on where these pilots must go risk their lives every day.
ReplyDeleteFreight dispatchers aren't the ones responsible for letting under-equipped airports remain that way. A highly paid government administrator owns that failure.
DeletePerhaps we should instead ask ourselves why our government prints money for the endless series of foreign wars and funding of every new citizen who wades across our southern border but we can't equip these airports with an ILS.
Put 14 billion on it. A few days later, add 800 million to hurry it up. It's just a matter of how priorities are arranged.
I totally agree with you. But... remember runways don't vote...
Delete"but we can't equip these airports with an ILS"
DeleteThat is a misguided statement, because it is not funding for an ILS but rather the surrounding obstacles at this airport that are preventing it from having better approaches. If the obstacle surface allowed it, they would have put in an RNAV LPV approach to this airport instead of an LNAV, which would have been just as good if not better than an ILS. We don't need to be paying for ILS equipment when RNAV approaches allow the same minimums with zero additional ground signal equipment at a fraction of the cost.
The only way throwing money at things would improve anything would be paying the surrounding businesses to move and take down their towers, stacks, and other obstacles that are preventing precision approaches, or move the entire airport to a more favorable location.
first opened in 1940, and publicly-owned by the CITY OF BURLEY, ID. The local city zoning allowed industry to build around the airport, not the feds.
DeleteLocals claim Burley Airport was dedicated on the 4th of July 1930.
DeleteA lot can happen in 92 years of growth.
https://burleyidaho.org/188/Burley-Municipal-Airport
I'm guessing she was tired and flying in bad conditions, with a wall of steam from those chimneys and a roof cleared of snow by heat, and she mistook the roof for the extended threshold. It's nearly parallel to the runway. The lights would have been hazy through a fog of snow and steam. Stereo vision would have been useless. A very strange UPS A300 crash in Birmingham was never assigned a direct cause - just CFIT below minimums. But I noticed something. The accident happened at sunrise and coincided with rush hour. There is a parallel expressway, I-20, beyond runway 24 - at that time of day it would have been crammed with bumper to bumper rush hour morning traffic with parallel lines of red and white lights, little dots repeating perfectly. Brain goes haywire, confuses an expressway for a dark runway, flies into a hill not knowing until the last minute. I once nearly killed myself by misinterpreting what was before me driving my motorcycle at night through mist. Strange things happen when you get tired.
ReplyDelete8:32 AM crash wasn't at sunrise. Sunrise was at 6:56.
DeleteShe would have been accustomed to crossing the waterway with the railroad bridge in view on the right side during the last moments in the normal approach to the RW20 threshold.
There is nothing to see that is even remotely similar to the waterway and RR bridge combination before reaching the tater plant.
Anyone know her duty schedule leading up to this accident?
DeleteBTW BOTH pilots on the above A300 reported the runway in sight - when it was hidden by a hill.
ReplyDelete...and both pilots followed provided vertical guidance as required for Part 121 aircraft even if the procedure results in a visual approach? They didn't even have the correct flight plan with the assigned approach procedure set in the FMC.
Delete"The captain’s change to a vertical speed approach after failing to capture the profile glidepath was not in accordance with UPS procedures and guidance and decreased the time available for the first officer to perform her duties." ...
"The captain’s poor performance during the accident flight was consistent with past performance deficiencies in flying nonprecision approaches noted during training; the errors that the captain made were likely the result of confusion over why the profile did not engage, his belief that the airplane was too high, and his lack of compliance with standard operating procedures." (NTSB)
Maybe what should come out of all this is some sort of program to break up such deadly illusions beforehand. E.g. suppose that building had been painted with a bold pattern and say a big potato image - no chance of mistaking that for a runway. And why not change the color of runway lights so the really stand out from the rest of the city? Even a small city is a maze of confusing lights at night. Try finding familiar streets in your town/city next time you fly in on a clear night. It takes a lot of practice even when you know exactly what you are looking at. Maybe make runway lights magenta, leave the centerline green. That's a stark contrast not likely to be mistaken for anything else.
ReplyDeleteWasn't at night. Crashed at 8:32 AM. Sunrise was 6:56.
DeleteVery sorry for her Family, she sounds like an amazing lady, should have lived to be an airline captain for many years, if thats what she was building time for....I have about a thousand single Pilot IFR hours between our CE-340 and Aztec F, both were very nice handling airplanes, but was taught by my CFII Dad, that if you cant get in the first time an go missed, its not going to get any better on the second try, and you will likely try to "force" your way in...just decide its time to go someplace else, and hopefully you brought enough fuel to get there...of course I flew part 91 and wasnt under any pressure to deliver the goods...my hats off to the freight dogs who have to fly in any weather, it just seems like a risky way to build time to a right seat at a regional..
ReplyDeleteHere's a better angle of the stack and ladder that were struck with the right wing where you can see the gash in the stack, and the damaged section of the ladder.
ReplyDeletehttps://gray-kmvt-prod.cdn.arcpublishing.com/resizer/Z9XA94vRdq5ABRdEofwGJeK0tGE=/1200x675/smart/filters:quality(85)/cloudfront-us-east-1.images.arcpublishing.com/gray/JNAC4GVPRBC7RHHQSIO3P2WAEY.JPG
Street view from US Hwy 30 in June 2019 of same stack
https://www.google.com/maps/@42.5508056,-113.7581799,3a,60y,310.62h,98.21t/data=!3m6!1e1!3m4!1sXjHKzC_zNsmc7-AQYHeIAw!2e0!7i16384!8i8192?hl=en
There is still data needed to determine amount of fuel in tanks. Paint transfer from impact points to determine the planes flight path.
ReplyDeleteThe MDA & displaced threshold is for the obstacles near the approach. The pilots forward view would be very limited almost nothing. The view under the wing would give you about a mile as reported at the airport.
It may have been mentioned earlier, but the leading edge of the left gear leg looks crushed. Perhaps it hit the chimney while the left wing just cleared the top. The plane would have yawed left, stalling the left wing and rolled inverted. When you look at Google maps, it's hard to reject the possibility, given poor visibility, that she mistook the roof for the threshold and dove for it. A plausible explanation that in no way reflects poor airmanship. My condolences to her friends and family.
ReplyDeleteThe dent in the stack is at the middle of the second from top section of flanged stack piping, a distance of approximately 14 feet below the top of the stack.
DeleteA C208 gear leg is not 14 feet below the wing, making it non-credible to suggest that the wing cleared the top but the gear leg struck the stack fourteen feet lower down.
As for the dive down mistakenly theory - what did she see that looked like the Snake river in front of the threshold?
in a snow storm maybe she wasn't looking for the snake river? Maybe she saw the snake river and runway but didn't see the stack? sadly, we'll never know what she was seeing or thinking in those final moments. But that stack never should have been there. Such a bad place for a 10 story tall obstruction :(
DeleteHere are 2 images of what ForeFlight synthetic vision would have shown at 4300' and 4560' (MDA) respectively... https://photos.app.goo.gl/dHgeEAniT9PpWu3o7
ReplyDeleteWould the FAA have allowed the company to mount a strobe on the top of that stack, or would it have interfered with the sight picture for a pilot on the glideslope for a landing?
ReplyDeleteA quick but not exhaustive search finds this example guidance from a past advisory circular regarding the use of a 24-hour medium intensity flashing white light system:
Delete"...not recommended on structures within 3 nautical miles of an airport."
Same document, regarding high intensity flashing white obstruction lights during daytime with automatically selected reduced intensities for twilight and nighttime operations:
"...should not be recommended on structures 500 feet (153m) AGL or less unless an FAA aeronautical study shows otherwise."
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2070%207460-1K.pdf
All GA pilots should know that a plume of steam vapour and condensate is a concentrated convective cell storm. The "Gem State Potato Processing Plant" blanches, cooks, and mashes potatoes 24/7. Conveyor belts feed mash to the bottom surfaces of six huge, slowly rotating steel drums that are heated internally by steam. The mash adheres to the drums, but is not exposed to the steam inside, and dries. On the descending side of each drum, flakes of dehydrated mash fall onto a second belt. Steam enters such drums at 140-180°C (284-356°F) and 10-12 bar. The plant releases huge quantities of hot water vapour through stacks, (industrial chimneys). The vapour warms the air as it cools and condenses, a process accentuated by a cold day. The hot vapour rises, but condensed droplets tend to fall. When there is wind, vapour rises up and away from the stacks, condenses, and begins to fall. The falling droplets drag air down. This entrained air can be warmer than ambient, especially on a cold day. On a hot day, fine droplets may evaporate before they can fall, so there is only rising air. If you are flying on a very cold day, (like Brittney Infanger), and enter a condensate cloud, you will be blinded and lose lift due to the anomaly of stagnant or descending warm air. (Hot air usually rises!) The aircraft’s surfaces will be substantially sub-zero, and the droplets “snap-freeze” on them, further cutting lift. On a cold day, the 020 approach to Burley Airfield could hardly be worse. Even a slight gust can carry the rising steam from the potato plant’s six stacks into the 3.75° approach path. The billowing clouds suddenly blind you, and the aircraft loses lift at the worst possible time. The condensate can blow into your path within seconds, unexpectedly. The single isolated stack is perfectly positioned to snag an aircraft that is suddenly enshrouded in the condensate clouds and losing altitude. It is staggering that the FAA, local airport authority, and board of the "Gem State Potato Processing Plant" allowed this appalling situation. Pilots who flew this approach repeatedly should have realised the peril, and taken action. It is nonsense to suggest that because the perfect approach was 100ft to the side of the stack and above it, that it was okay! Given the wing spans of aircraft, the rising steam, and a gusty day, 100ft is much too little. At the least, the isolated stack should have been brightly illuminated using LEDs, and painted with alternating yellow and black rings along its entire height. Burley Airfield should either stop 020 approaches, and/or the "Gem State Potato Processing Plant" should run a pipe up from the Snake River to condense and recover its steam inside the factory, and reposition that isolated lethal stack. Brittney Infanger was a highly skilled and trusted pilot. I am extremely sorry for her parents and other loved ones. Regardless of the precise reasons for her own accident, the FAA, Burley Airfield authority, and the board of the "Gem State Potato Processing Plant" have very serious questions to answer.
ReplyDeleteMaybe it was a slow day at the Tater plant, but the "plume of steam vapor" from the stacks shown in the following aviation video seems fairly small and underwhelming. Not exactly the type of volume that would create "a concentrated convective cell storm." Granted, the winds were strong on the day this video was shot, but I can't imagine it being much worse on a calm day. If anyone has photo/video evidence to the contrary, please share.
Deletehttps://youtu.be/fNIsBWj6nok?t=149
Excellent video, probably should cue up for 2:20 and tell folks to set speed to .25 because starting at 2:29 only allowed about two seconds of viewing before it's off to the races. :-)
DeleteTry this, cued t=140, set it to .25 speed, 2:20 to 2:31 to see plume:
https://youtu.be/fNIsBWj6nok?t=140
You might want to rethink that comment about the condensation plume from the plant being "underwhelming." Remember, is was a cold, snowy morning, with very limited visibility, and according to the AWOS at the time of the crash, the temperature/dewpoint spread was only two degrees; in other words a very nearly saturated atmosphere. A local phenomena, such as a plant pumping massive amounts of moisture into the air under those conditions is going to produce significantly more of a condensation plume than it would on a drier day (as would be more typical in that region). To wit, check out this video at the 16:46 mark:
Deletehttps://youtu.be/aRN3RJaW618
Here's an even better view of what those steam stacks do on a morning with very similar weather conditions to the crash. Even from a short distance, the stacks are completely obscured. See 6:45 in the video: https://youtu.be/M6ev-hmvtag?t=405
DeleteWitness who was close by said the 208 descended out of the clouds and immediately flew into the steam seconds before hitting the tower. Not enough time for the air frame to ice up from steam. Possible it was slightly iced during the approach to JAMID.
Deletefirst opened in 1940, KBYI is publicly-owned by the CITY OF BURLEY, ID, which the father is demanding be closed. As seen in many urban locations, local city zoning permits industry to build around urban airports. Maybe Burley and the state of ID can get a 90% grant to build new from feds $3 billion in new funds for airports under Prez Biden and the Dem's passed infrastructure law.
ReplyDeleteFour years ago, Burley airport lost their Federal Aviation Administration funding because it did not meet their safety standards due to short runways. The airport cannot expand because it is landlocked between the Snake River and train tracks. The best option for them is to create an entirely new airport in a different location, something they need FAA funding for, and to run the airport the City of Burley is seeking to establish an airport authority.
DeleteFrom over a year ago: https://www.kmvt.com/2021/02/26/the-fate-of-the-burley-municipal-airport-continues-to-be-uncertain/
Tater plant has more political clout and money then a city owned airport. They see the tater plant as a job producer airport more of a nuisance. It's just the view of residents. I grew up near a small airport most people just complained about the noise, and crashes until it was shut down tract homes were built there.
DeleteWhen I look at Google Earth and that smoke stack it obvious it was only a matter of time before that stack met a plane trying to make the runway. It was a 100% bound to happen eventuality.
ReplyDeleteI'm heartbroken it happened to such a bright and lovely soul as Brittney. She was truly amazing.
"It was a 100% bound to happen eventuality."
DeleteThose stacks were well outside where any airplane should ever find itself. Look at the Blancolirio video on YT, he shows where they were in relation to the runway. She was WAY low to have hit those. The only question is why. We know the outcome.
Don't bust minimums.
I only have about 8,000 hours behind PT engines, so what do I know?
DeleteI have never experienced a flameout . I only flew in the eastern, midwestern, western, and northern United States milieu in those 30 years, so maybe i didn't see enough. It makes my heart sick to think about what this delightful person must have gone through. We are all guessing. I will say that the analyses here have been very well thought out and thought provoking. This seems to fall into the category of :"stuff happens."
"Those stacks were well outside where any airplane should ever find itself. "
DeleteB.S. See
this image that shows the stacks are directly on a standard 3 degree descent angle and there is no VSGI lighting to warn you otherwise. The instrument approach has no vertical guidance, so you are on your own to see and avoid these obstructions which have no lighting during the day. Do you think it's unreasonable for a pilot to descend to a standard 3.0 degree glidepath once they have the runway in sight?
“you think it's unreasonable for a pilot to descend to a standard 3.0 degree glidepath once they have the runway in sight?”
DeleteWhen the glidepath specified on the approach is 3.75 degrees, yes, yes I do.
The silos were within TERPS requirements. This was going under minimums on a non-precision approach and the results are as expected. Only difference is the pleasurable physical appearance of the pilot. Aviation don't care who you are. Don't bust minimums, ladies and gents.
ReplyDeleteSilos? Are youtube's oracles saying a silo was hit?
DeleteSilos are adjacent but it was the #16-036731 stack in the obstruction database that was hit. 100' tall.
Did this pilot really cheat on the minimums?
Youtube channels have successfully assigned their opinion to loyal fanboi followers before the investigators determine whether a rare case of faltering PT-6 output steepened the approach.
Given the multitude of N928JP landings across the Gem plant at BYI keeping that regularly scheduled milk run going, plus the divert on the previous day, wilful pilot disregard of minimums is not a certainty.
Mindlessly yay-howdy-ing the assertion that the pilot was wilfully reckless will lead to regret if the click-generating "Occam's razor" assumptions reaching KR from YT fans turn out to be incorrect.
"The silos were within TERPS requirements."
DeleteGee, thanks Captain obvious. The FAA isn't in the habit of approving approaches that don't meet TERPS, so that is a given. It would be more enlightening if you pointed out that due to TERPS, the only approach that could be approved was a non-precision LNAV with no vertical guidance and a steep 3.75 descent angle due to the silos and other obstructions.
"Don't bust minimums."
It's not a minimums bust if you have any of the required runway elements in sight before you descend. The reported ceilings were well above the MDA, so unless you were sitting in the cockpit next to the pilot, you have no idea if they could make out the runway or not when they passed the MDA. The obstacle she hit was less than half a mile from the runway and at or below 100 AGL, so unless you think the weather somehow magically decreased to 200 ft ceilings and half a mile vis, she definitely had the runway in sight well before she hit the obstacles, so "busting minimums" was not a factor.
If you are focused on approaching a short runway, there is no VSGI to guide you on the required steep non-standard descent angle, it can be easy to miss the grey colored obstacles that don't stand out.
How often have you ever flown an approach to minimums? Bet you have very limited Actual instrument hours if any.
Delete"It would be more enlightening if you pointed out that due to TERPS, the only approach that could be approved was a non-precision LNAV with no vertical guidance and a steep 3.75 descent angle due to the silos and other obstructions."
DeleteFalse.
"It's not a minimums bust if you have any of the required runway elements in sight before you descend. The reported ceilings were well above the MDA, so unless you were sitting in the cockpit next to the pilot, you have no idea if they could make out the runway or not when they passed the MDA."
It doesn't seem like you understand how ASOS works.
"The obstacle she hit was less than half a mile from the runway and at or below 100 AGL"
Correct. So if as you are saying she had the runway in sight, why on God's green earth was she 100 feet AGL a half-mile from the runway?
"If you are focused on approaching a short runway, there is no VSGI to guide you on the required steep non-standard descent angle, it can be easy to miss the grey colored obstacles that don't stand out."
4,000 feet is short for a Caravan? The only way to hit the obstacles is to be WAY low on the approach. Sorry.
Your nonsense responses like "false" with zero explanation demonstrates that you have no actual idea what TERPS, an obstacle clearance surface, and approach minimums are. Sorry your flight sim game didn't cover that.
Delete"why on God's green earth was she 100 feet AGL a half-mile from the runway"
How about any number of reasons that many aircraft have crashed in VMC with the runway in sight: engine failure, icing, wind sheer, pilot incapacitation, etc. If you knew how an ASOS worked, you'd know it wasn't anything to do with being in IMC.
"4,000 feet"
How to tell us you aren't a pilot without telling us you aren't a pilot. Ever heard of a displaced threshold? Runway 20 has one. There are less than 4,000 feet available for landing. Precision matters to actual pilots.
"Your nonsense responses like "false" with zero explanation demonstrates that you have no actual idea what TERPS, an obstacle clearance surface, and approach minimums are."
DeleteGiven that the approach predates the stack she hit, I'm just guessing that the stack was not the reason why there is only an RNAV approach. So, again, false.
"If you knew how an ASOS worked, you'd know it wasn't anything to do with being in IMC."
Yeah, no. You clearly don't know how ASOS works. The reported weather doesn't mean anything about conditions at the accident site.
"How to tell us you aren't a pilot without telling us you aren't a pilot. Ever heard of a displaced threshold? Runway 20 has one. There are less than 4,000 feet available for landing. Precision matters to actual pilots."
Oh yes, you got me there. So according to Jepp, the usable runway length is 3,787 feet. So are you going to tell me that's not enough to get a Caravan down and stopped? GMAFB.
And insulting me (or trying to) doesn't speak to the weakness of my position, but rather the weakness of yours.
"Given that the approach predates the stack she hit"
DeleteThe current approach is dated Jan 30, 2020. There is photographic evidence of the stacks on the roof at the collision location in a 2018 Town News article about the plant, so they have been there at least that long. Try again.
Sure, reported airport weather can be different than what you experience on approach, but it is quite unlikely that less than 1 mile off airport, the ceilings dropped from 2100 AGL to 200 AGL and visibility halved from 2SM to 1SM to keep the pilot in IMC when the airport weather was trending in the opposite direction. That's magical thinking to support a flawed theory about busted minimums.
The earlier comment just said "short runway", no one said anything about not being able to land a Caravan on it. Seems like you are grasping for something to be upset about, or need to work on reading comprehension.
The FAA also thinks the runways at Burley are short. So short that they don't meet FAA safety standards. But hey, what do they know? https://www.kmvt.com/2021/02/26/the-fate-of-the-burley-municipal-airport-continues-to-be-uncertain/
DeleteN928JP diverted to Twin Falls on the day before the accident. The decision to divert was made before descending from cruise altitude. Presumably, the decision to descend from cruise altitude for BYI on the accident day followed similar protocol.
ReplyDeleteLet's look at the METARs available for making the real-time decision on each of those two days:
The divert from BYI to Twin Falls on the day before the accident shows up as a turn toward TWF underway at 14:52:44 Z. Here are BYI and TWF METARs from that time:
KBYI 121450Z AUTO 26015G23KT 1SM -SN BR BKN010 BKN019 OVC029 M03/M04 A2971
KTWF 121450Z AUTO 27018KT 10SM OVC033 M03/M06 A2975
METAR while landing TWF's 8,700' length RW26 at 15:12 Z on 12 April:
KTWF 121510Z AUTO 29021KT 8SM -SN SCT024 OVC030 M02/M06 A2975
On the accident day, initial descent into BYI from cruise was underway at 13:59:16 Z. Here are BYI and TWF METARs from that decision time:
KBYI 131355Z AUTO 20005KT 6SM -SN BR FEW019 BKN026 OVC033 M03/M06 A2996
KTWF 131353Z 24008KT 10SM BKN060 BKN075 OVC095 M02/M06 A2997
(That decision to descend for BYI on the accident day didn't have the gusty wind, 1000' broken and one mile visibility conditions of the divert to TWF decision on the previous day)
Visibility degraded during descent for the first BYI approach attempt:
KBYI 131401Z AUTO 20008KT 2 1/2SM -SN BR BKN026 OVC033 M03/M05 A2996
KBYI 131405Z AUTO 20008KT 1 1/2SM -SN BR BKN026 OVC035 M03/M06 A2996
KBYI 131410Z AUTO 19008KT 1SM -SN BR BKN023 OVC028 M03/M05 A2996
KBYI 131415Z AUTO 20008KT 1SM -SN BR BKN021 OVC028 M03/M06 A2997
Conditions while circling back around for another try:
KBYI 131420Z AUTO 20007KT 1SM -SN BR BKN021 OVC026 M03/M06 A2997
KBYI 131425Z AUTO 20008KT 1 1/2SM -SN BR BKN021 OVC028 M03/M06 A2997
KBYI 131430Z AUTO 20007KT 2SM -SN BR BKN021 OVC028 M03/M06 A2997
(Crash was at 14:32 Z)
(The above information was offered to show reports from the BYI automatic weather system for the full period covering the initial descent decision through to the crash at 14:32 Z. That full sequence of reports showing 6, 2 1/2, 1 1/2, 1. 1, 1, 1 1/2, 2 statute mile visibility was not previously discussed in comments.)
-- Source links --
The accident flight:
https://flightaware.com/live/flight/N928JP/history/20220413/1300Z/KSLC/KBYI
The diverted flight on April 12:
https://flightaware.com/live/flight/N928JP/history/20220412/1300Z/KSLC/KTWF
Raw archive METARs for BYI & TWF, 12 & 13 April:
https://mesonet.agron.iastate.edu/cgi-bin/request/asos.py?station=BYI&station=TWF&data=all&year1=2022&month1=4&day1=12&year2=2022&month2=4&day2=14&tz=Etc%2FUTC&format=onlycomma&latlon=no&elev=no&missing=M&trace=T&direct=no&report_type=1&report_type=2
There wasn’t a lot of time for the pilot to set up the second approach prior to the really abbreviated vectors to the final approach. I have tried to comprehend the possible reasons for a Caravan to be flying below 90 knots and descending close to 900 feet per minute (per ADS-B/FlightAware) dangerously below the published Minimum Descent Altitude (MDA) on the RNAV/LNAV GPS Runway 20 approach to Burley, Idaho (KBYI)Airport. The KBYI AWOS observations already cited above all gave evidence of Icing Conditions of -SN (“light snow”) and below freezing temperatures. Juan Brown on the Blancolirio YouTube Channel mentions the icing conditions. It is possible that the Pratt and Whitney PT-6-114A, 675 shp Turbine engine experienced a flameout which would result in an immediate loss of power and subsequent descent. The Flight Safety Cessna Caravan Emergency Memory Items Check List calls for Airspeed…85 KIAS for Model 208 without flaps or with 20 degrees flaps for an Model 208B Engine Failure Immediately After Takeoff. There is no published airspeed for Engine Failure on Approach Emergency Checklist.
ReplyDeleteNote: The Pratt and Whitney PT-6 Turbine was originally designed to pump water, hence the nomenclature “PT” for pump turbine. The PT-6 has a world wide reputation for reliability and resilience even under adverse atmospheric conditions. It is however possible to experience a flameout and subsequent loss of power under certain conditions. One possible cause of a flameout could be the accumulation of ice and snow on the PT-6 turbine compressor section intake screen. Although the intake air has to take a 180 degree turn (so called reverse flow) in order to enter the compressor section, it is possible to encounter sufficient ice and snow accumulation to cause a flameout. The Flight Safety Emergency Checklist Memory Items for an Inadvertent Icing Encounter calls for:
(1) Ignition Switch ….ON
(2) Inertial Separator…BYPASS (bypasses precipitation past the intake back out in the slipstream)
(3) PITOT/STATIC, STALL, WINDSHIELD, PROP, ANTI-ICE…ON
The FAA/NTSB Safety Investigators hopefully have noted the various switch positions of all the above, whether the Inertial Separator was placed in the BYPASS position, and whether wing flaps were selected.
I am not aware of whether this was an older model of Cessna Caravan equipped with legacy round instrument gages and the old booted deice system. Older Model Caravans have a history of crashes in icing conditions. Newer editions of the Cessna Caravan contain updated glass instrumentation with Garmin G600 or G1000 systems and weeping wing TKS ice prevention systems.
Please do not assume that classic rookie pilot mistakes are at play here. What if the circumstances were such that might have overwhelmed any level of experience?
Been there, done just about all the above. Fortunately never had a flame out.
Cessna C208B Caravan Captain Freight Dog
Agreed - not assuming willful pilot disregard of minimums until PT-6 operation is evaluated is the responsible viewpoint until investigation makes determinations.
DeleteAccident aircraft was a 2013 production aircraft, not a steam gage model.
"I have tried to comprehend the possible reasons for a Caravan to be flying below 90 knots and descending close to 900 feet per minute (per ADS-B/FlightAware) dangerously below the published Minimum Descent Altitude"
DeleteYou might want to comprehend this:
1. FlightAware's track log is heavily sampled and rounded, showing one track point every 20-30 seconds despite ADS-B transmitting a data point every second. So you can't put much stock in the shown FlightAware track log data being that accurate.
2. FlightAware displays ground speed, not IAS, so you have to account for winds loft, which can be significantly higher than reported surface winds.
3. FlightAware displays altitudes as uncorrected pressure altitude, so you have to correct for the altimeter setting which in this case would add at least 50 feet.
4. The RNAV RWY 20 approach requires a significantly steep descent angle of 3.75 degrees from the FAF, which would require a 700-800 fpm decent for typical Caravan approach speeds.
5. The lowest reported cloud layer was 1500 feet higher than the MDA. The MDA is no longer applicable once you have the airport in sight.
The #5 comment about lowest cloud layer is important to grasp. It should also be noted that visibility was two miles just two minutes before the crash and 2.5 miles eight minutes after the crash.
DeleteHere are those METARs:
KBYI 131430Z AUTO 20007KT 2SM -SN BR BKN021 OVC028 M03/M06 A2997
--- crash occurred @ 14:32 Z ---
KBYI 131440Z AUTO 21008KT 2 1/2SM -SN BKN030 OVC047 M03/M06 A2997
In spite of those reports, the pilot's reputation is being maligned with the "intentionally busted minimums" assertion.
The last "reliable" data point on ADS-B was @ 08:32:25 at an altitude of 4150' MSL and a position of 42.5520,-113.7592 which is almost directly at the stack. I know this is an uncorrected altitude for temp/pressure so if you add the 50 to 100' as suggested above for correction, that would put the aircraft at about 4250' MSL. The stack is depicted on the approach plate as being 4304' MSL. The aircraft was well below the 3.75 degree "glidepath" at this point from the FAF to the TDZE of 4152'. I know this is a LNAV approach so vertical guidance is not provided as it is on a precision approach.
DeleteHere is the approach plate: you have to zoom in to see the 4304' stack
https://flightaware.com/resources/airport/BYI/IAP/RNAV+(GPS)+RWY+20/pdf
Here is the track-log:
https://flightaware.com/live/flight/N928JP/history/20220413/1300Z/KSLC/KBYI/tracklog
To Anonymous, dated Tuesday, April 19, 2022 at 2:55:00 AM EDT
DeleteQuestion: What explanation do you have besides your technical dissertation of how to interpret ADS-B data for what occurred besides the broken “busted minima” mantra? Better yet, how about a test of your instrument skill set with added emergencies? Take the time and money to buy sim time to replay the weather and the two approaches with the missed approach scenario in question in a Cessna Caravan sim. Add a loss of power situation and see how you come out. I venture that your confident swagger and language will be forever humbled. A non-precision step down IFR approach to minimums is one of the hardest things any Pilot is ever called upon to do.
You're missing his point entirely. He was simply stating facts about how ADSB data are disseminated. Besides, every "pilot" who mentions how "slow" an aircraft was flying based on these data have lost complete credibility and their opinions are not relevant. Ground speed has zero to do with how a wing flies. All 5 of his points are irrefuteable.
DeleteI think you are attacking the wrong anonymous commenter. The comments at Tuesday, April 19, 2022 at 2:55:00 AM were debunking the broken "busted minimums" mantra that some armchair NTSB investigators on here are parroting here from their misinterpretation of inprecise FlightAware data. The pilot did not bust minimums nor was this anywhere near an approach to minimums. Ceilings were 1600 feet higher than minimums. That's not saying it isn't a challenging approach but something else was going on here. A loss of power, icing, or other emergency situation is definitely possible.
DeleteFYI, the 4304' obstacle shown on the RWY 20 approach plate plan view is NOT any of the stacks at Gem State plant. That obstacle is this 140 foot radio tower near the United Metals Recycling plant, which is 0.6 NM north east of the Gem State stack:
Deletehttps://www.google.com/maps/@42.5584036,-113.7480359,3a,86.2y,335.86h,111.79t/data=!3m6!1e1!3m4!1sfD-logCbUr79CSW4DcVyPQ!2e0!7i13312!8i6656
None of the Gem State stacks are shown anywhere on the approach plate.
As a former freight dog, we had many rules of thumb or personal SOP, and the published current charts, OP Specs, and FARs. These would apply to a frequent, small, non-precision, destination airport, and those of us that taught approaches appreciated visualizing the descent or stepdowns to MDA. Perhaps this was the pilot's first flight to Burley, or an infrequent stop?
DeleteOther measures for safety and possible fatigue: No snake river or other possible, large visual cue in sight? Do NOT descend below xxx MSL (example). Potato plant in sight, underneath aircraft? Begin final portion of descent to the runway numbers.
From the Flight Aware track log from 10:31:37 EDT to 10:32:04 EDT, a timeframe of 27 seconds, the plane lost 22 knots of ground speed and lost 300 feet in altitude. That sounds like either icing or engine failure or both to me.
DeleteIt is possible to calculate the as-flown descent angle that the aircraft experienced between the final two full ADS-B data points and see if it was 3°, 3.75° or something else using rise run to angle conversion.
ReplyDelete(All of the info presented below is offered with the understanding expressed in this posting and by others regarding usage of ADS-B data. Skipping to the end and resuming reading at the next to the last paragraph is recommended if you don't want to read all of the details.)
For rise, the difference between the uncompensated raw reported altitudes at the two points will be used. (ADS-B granularity in increments of 25 feet altitude, with rounding and accuracy limitations in FlightAware's processed data reduces precision, but attempting to compensate each point for local pressure variation from 29.92 is eliminated by this technique.)
Here are those two points, with map-pinned locations, measured distance between them and difference in raw reported altitude:
Data and mapping at the edge of the Gem building:
Wed 10:32:25 AM 42.5520 -113.7592 ↙ 217° 80 92 4,150 -857
Call this Data Point "A" and google map pin it:
http://maps.google.com/maps?t=k&q=loc:42.5520+-113.7592
Data and mapping at 21 seconds and 2,650 feet horizontal distance before reaching the Gem building's edge and 300 feet higher:
Wed 10:32:04 AM 42.5578 -113.7532 ↙ 216° 81 93 4,450 -750
Call this Data Point "B" and google map pin it:
http://maps.google.com/maps?t=k&q=loc:42.5578+-113.7532
Determine angle using rise run:
Rise: -300 feet
Run: 2,650 feet
Flown descent angle between final two data points = -6.5°
Now, repeat the calculation from JAMID to "B":
First, find JAMID coordinates from FAA database:
JAMID location coordinates: 42-33-59.2100N 113-44-39.3500W
JAMID location converted to decimal: 42.566447, -113.744264
Map pin the location of JAMID:
maps.google.com/maps?t=k&q=loc:42.566447+-113.744264
Choose nearest ADS-B data point to JAMID from FA track log:
Wed 10:31:37 AM 42.5669 -113.7437 ↙216° 103 119 4,750 -663
Call this Data point "C" and google map it:
maps.google.com/maps?t=k&q=loc:42.5669+-113.7437
(JAMID's location maps about 200 feet SWest of this data point)
N928JP's location at JAMID includes an uncorrected altitude of 4,750 feet, 300 feet higher than and 4,166 feet horizontally distant from the Wed 10:32:04 AM 42.5578 -113.7532 data point "B".
Determine angle from JAMID to "B" using rise run:
Rise: -300 feet
Run: 4,166 feet
Flown descent angle between JAMID and point "B" = -4.1°
Everybody understands that ADS-B can be terribly inaccurate, but when you add the expected +50' pressure correction to the 4,750' reported at JAMID, the data suggests that the pilot appears to be "on" at JAMID. Prior to that, the 6,950' altitude transmitted while going back for the second attempt adjusts to the expected 7,000' with the +50' compensation.
After being "on" at JAMID, these were the descent angles flown:
From JAMID to Data Point "B", angle flown was -4.1°
From Data Point "B" to Data Point "A", angle flown was -6.5°
For comparison of speeds, alts, angle flown, map-pin locations:
DeleteC208B N585SA flew N928JP's duty/schedule SLC to BYI on 15 April.
https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=N585SA
N585SA's landing 15 April into Burley RW20 in VFR conditions:
https://flightaware.com/live/flight/N585SA/history/20220415/1339Z/KSLC/KBYI
https://flightaware.com/live/flight/N585SA/history/20220415/1339Z/KSLC/KBYI/tracklog
METAR during landing:
KBYI 151430Z AUTO 27009KT 10SM FEW043 BKN055 OVC080 01/M02 A2992
(Note A2992 in METAR, makes reported ADS-B altitudes true)
At location 355 feet NEast of JAMID as Data Point 1:
Fri 10:33:11 AM 42.5672 -113.7434 ↙216° 120 138 4,825 -830
maps.google.com/maps?t=k&q=loc:42.5672+-113.7434
Data Point 2, -225'AltDiff, 3,415' distant from 1 = -3.8°
Fri 10:33:28 AM 42.5598 -113.7511 ↙219° 120 138 4,600 -821
maps.google.com/maps?t=k&q=loc:42.5598+-113.7511
Data Point 3, -350'AltDiff, 5,115' distant from 2 = -3.9°
Fri 10:33:53 AM 42.5487 -113.7627 ↙217° 119 137 4,250 -840
maps.google.com/maps?t=k&q=loc:42.5487+-113.7627
Raw 15 April BYI METAR link:
https://mesonet.agron.iastate.edu/cgi-bin/request/asos.py?station=BYI&data=all&year1=2022&month1=4&day1=15&year2=2022&month2=4&day2=16&tz=Etc%2FUTC&format=onlycomma&latlon=no&elev=no&missing=M&trace=T&direct=no&report_type=1&report_type=2
When substitute C208B N585SA flew N928JP's duty/schedule into BYI RW20 two days after the crash in VFR conditions as detailed above, that pilot maintained 120 knots ground speed plus the headwind at the time resolved from 27009KT at BYI.
DeleteThe 3.8° to 3.9° angle flown by the substitute aircraft on 15 April between JAMID and Data Point 3's 7th avenue at Snake River location was NOT a "clear the potato plant, then dive for the runway" approach.
Was the accident pilot accustomed to flying at a lower approach speed into BYI than she would maintain for a longer runway, such as TWF?
The divert landing to TWF RW26 on the day before the accident shows 102 knots ground speed in the 27018KT wind there, which is an airspeed of 120 knots at that last data point located approximately 2100 feet distant from the threshold:
maps.google.com/maps?t=k&q=loc:42.4805+-114.4631
The accident aircraft's 4 April landing to BYI RW20 in VFR conditions showed 87 knots ground speed in the 23009KT wind there at the time, which is an airspeed of 96 knots at that last data point located just after passing over the potato plant:
http://maps.google.com/maps?t=k&q=loc:42.5501+-113.7611
It is possible that the accident pilot was accustomed to routinely flying the BYI approach at reduced airspeed but experienced diminishing lift at the lower approach speed during the accident approach due to contamination accumulation on flight surfaces that built up during two approach attempts in light snow and mist.
She was "on" at JAMID, flew a 4.1° descent angle about halfway to the potato plant, then the descent angle increased to 6.5° in the final 21 seconds on the way to the stack.
Links:
Diverted flight, 12 April:
https://flightaware.com/live/flight/N928JP/history/20220412/1300Z/KSLC/KBYI
Previous N928JP BYI RW20 landing, 4 April:
https://flightaware.com/live/flight/N928JP/history/20220404/1318Z/KSLC/KBYI
Her distraught father, Jim Bob Infanger (right), has said " Brittney knew the area well and flew to Burley International Airport all the time". He blamed a hazardous chimney on the Gem State Processing Plant for the deadly crash.
ReplyDeleteHmmmmmm! From the many news sources......
From the ntsb, it was the steam cloud:
Delete"According to a witness, located about one quarter mile away, he first heard, then observed the airplane descend out of the clouds then immediately went into a steam cloud, which was produced from a set of six smokestacks located on the same roof. The witness heard the engine increase in sound and saw the nose lift shortly before the airplane struck the smokestack and descend to the rooftop."
Solo/Missed Approach/Marginal Conditions/Challenging Airport = High Stress
ReplyDeleteIt's the perfect setup for one of those 'undiagnosed preexisting medical conditions' that have been making the rounds these days with athletes.
The coroner's report should be interesting - condolences to her family.
youre implying that a 30 year old female had a major medical incident the moment she was on final approach in marginal wx and that caused the accident. a pilot is not an athlete either. i know what my $ is on and it isnt your theory.
DeleteWhat are you running with? 80 y/o Airport in wrong place, or decades old Tater Plant position?
DeleteThe Gem plant was described as newly constructed when highlighted in a 2012 upgrade project info page:
Deletehttp://www.roguepump.com/documents/gem-state-processing-case-study.pdf
The Gem Plant in Heyburn shows up at 2010 on the company history timeline, here:
Deletehttps://www.oregonpotato.com/aboutopc/#history
January 2011 news article expected the new plant to be up and running spring or early summer that year:
Deletehttps://www.potatopro.com/news/2011/burleyheyburn-dehydrated-potato-plant-open-early-year
The YouTube "Clown" commingled an half-assed apology with begging for $cash money$ be sent to him.
ReplyDeleteHe saw the KR comments detailing 2 statute mile visibility METAR trending 2.5 miles with lowest clouds well above MDA and also the correlated and mapped descent angle calculations.
DeleteTuber commenting by the mindless fans is praising him for apologizing in what was just his latest heartless disparaging of a lost pilot for views. He owns the minds of those fans and is working toward harvesting their donations in the times ahead.
To Anonymous, use a fake name so I can see who the insults are directed at
ReplyDeleteIs snow considered icing conditions?
Snow doesn't always equal known icing conditions. If you fly through a light, dry snow shower, you're unlikely to see ice accumulation. But if the temperature is warm (roughly 0C to -5C), wet snow mixed with liquid water could to stick to your airplane.Dec 11, 2021
Frost disrupts the smooth flow of wind over the wing causing reduced lift. It increases the weight of the aircraft and changes the weight and balance. Frost changes the basic aerodynamics of the airfoil, thereby causing reduced lift.
Ice collects on and seriously hampers the function of not only wings and control surfaces and propellers, but also windscreens and canopies, radio antennas, pilot tubes and static vents, carburetors and air intakes. Turbine engines are especially vulnerable. Ice forming on the intake cowling constricts the air intake. Ice on the rotor and starter blades affects their performance and efficiency and may result in flame out. Chunks of ice breaking off may be sucked into the engine and cause structural damage. The first structures to accumulate ice are the surfaces with thin leading edges: antennas, propeller blades, horizontal stabilizers, rudder, and landing gear struts. Usually the pencil-thin outside air temperature gauge is the first place where ice forms on an airplane. The wings are normally the last structural component to collect ice. Sometimes, a thin coating of ice will form on the windshield, preceded in some instances by frosting. This can occur on take-off and landing and with sufficient rapidity to obscure the runway and other landmarks during a critical time in flight.
@billy - No reason to expect insults. Comments upthread didn't draw insults to the suggestion that N928JP may have experienced diminishing lift due to contamination accumulation on flight surfaces that built up during two approach attempts in light snow and mist.
DeleteThis part of what you wrote seemed odd, however:
"Ice on the rotor and starter blades"...
Turbine engines have sets of rotor and stator blades. The "starter" typo is an immediate and huge tell to everyone with turbine engine knowledge.
Searching for "Ice on the rotor and starter blades" finds lots of copy and paste repetitions online of someone's long ago unnoticed autocorrect goof that changed stator to starter.
The Weather.gov page that contains your copied text paragraph verbatim may have been the origin of all the other bad "starter blade" pastes over the years. It's interesting to see search results reveal the unattributed copying that the error gives away.
Posting the full source info link is a good practice that provides complete information in proper context. Here are links to the Weather.gov Icing page containing the text block where the "starter" typo originated and the FAA's Flight in Icing Conditions circular:
https://www.weather.gov/source/zhu/ZHU_Training_Page/icing_stuff/icing/icing.htm
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_91-74B.pdf
Yes,you are right, I did a copy and paste and wanted to refresh myself on comments on icing perhaps being a factor which I didn't know could happen in light snow. Also, someone suggested that the engine might of cut out which I never heard as an issue for that engine.
ReplyDeleteA lot of theory's and conjecture which I find every theory interesting. Let me throw mine out there if I may:
The simplest, a descent to MDA that was not arrested. that happens in many non precision approaches, very common.
Someone commented:
At reaching the edge of the building, 80 + 8 = 88 knots:
Wed 10:32:25 AM 42.5520 -113.7592 ↙ 217° 80 92 4,150 -857
Airspeed of 88 is ok, yes it fell off but stalling speed is in the low 60's.
2nd the descent rate is -857. Even if the tower and building wasn't there and the Bonneville salt flats was in front of the plane she would be touching down in the next 6 seconds. If the pilot could see to descend below MDA, you they think they would see the building , the tower, and or the parking lot beyond the building, so I conclude she didn't see it, due to either white out conditions or head in the cockpit, (which is absolutely normal on an instrument approach). So the only problem left is not arresting the descent rate. (Which is common in CFIT accidents non precision approaches). Even if you were trying to duck under, you aren't ducking at -857/min at 4800 ft. (Jamid) MDA 4560 which is 240 ft then another 406 ft 4154 elevation - 646 fpm would get you there (at 90 knots). -480 , for the first 30 seconds to MDA then -800 for the last 30 seconds would avg - 640. She established -857 and kept it there and kept going. She was going to hit something as that rate was not arrested. The building/towers are a red herring, imho.
Loved ones can't blame the person they just lost. I'd be the same. The "airport shouldn't be there"
I'm reminded of the jet that took off in CT short runway. Family said "he was a great guy" Must of been a mechanical problem!" Well he set the brake and forgot to release it.
@billy - The accident pilot was initially flying a 4.1° descent angle leaving JAMID, with 1.6 NM remaining to the RW20 threshold. The data point location after which the 4.1° descent angle increased to 6.5° is one statute mile from the threshold.
DeleteThe initial 4.1° descent angle compares favorably with the 3.8° to 3.9° angle the company's substitute pilot flew in VFR conditions from JAMID all the way to 7th Avenue just two days after the accident, but a notable difference is that the accident pilot's 88 knots airspeed was 40 knots slower while experiencing mist and light snow.
"Ducking under" wasn't still on the accident pilot's to do list by the time JAMID was reached. (Flight at 6,200' MSL and below was "under" based on lowest layer of BKN021 reported in the METARS for the elevation 4,154 MSL field.)
Investigators have the task of figuring out why the descent angle increased to 6.5° in the final 21 seconds/2,650 feet horizontal travel distance of flight. With luck there will be a SD card data record to help in understanding.
If visibility was 1 SM, and the ASOS is 600' west of the threshold, then the pilot broke out only 2100' (lateral distance) before the tower. If she was at MDA at that moment, then the average descent angle from VMC to tower is close to 9 degrees. Flying time at 80 kts ground speed was just 16 sec, break out to tower. However the one eye witness tells a different story. I believe the approach was unstable, in and out of IMC from JAMID.
DeleteI can't understand why this approach even exists. The approach path passes just above the smokestack, and there's no vertical guidance because it's LNAV only. (Lateral integrity of 0.3 nm.)
ReplyDeleteHow far is the approach path above the smokestack? Let's do the math.
The collision smokestack is 2,639' from the threshold (measured on Google Earth).
From the approach plate "RNAV (GPS) RWY 20 Burley Muni BYI": The approach path angle is 3.75 degrees. Threshold Crossing Height is 40'. Quick trig (sin 3.75 x 2,639') says that's 173' above the 40' TCH, so 173' + 40' = 213' above touchdown elevation. Touchdown elevation is 4,152'. So 4,152' + 213' = 4,365' MSL at the smokestack. The approach plate shows the smokestack at 4,304' MSL. 4,365' - 4,304' = 61'.
Answer: the FAA-approved non-precision approach path is 61' above the smokestack.
Sorry, but that's insane.
You can pull data all day long from flight records and try to figure out why she did what she did, but the fact remains that a published non-precision LNAV approach that misses a smokestack by 61' is unacceptable. If I have it wrong, please correct me.
One correction for your analysis: The elevation of the stack she hit is 4256' MSL in the FAA's obstacle database.
DeleteUsing your calculation of the flight path elevation at the stack, applying the FAA's verified stack elevation revises your math to:
4,365' - 4,256' = 109'.
The top of the stack is 109' below the flight path. And if your flight path elevation there is correct (not saying it isn't), 4,365 is below the MDA of 4,560 so all pilots would have visual conditions before reaching it by simply following the MDA protocol.
Here is the record for the stack she hit, obstruction #16-036731.
16-036731 O US ID HEYBURN 42 33 05.92N 113 45 34.15W STACK 1 00100 04256 R 4 D P 2016ANM01617OE A 2017285
Full stack record discussion showing the source data origin, how to decode the obstacle record and a position verification to be certain of the correct match by mapping the 42 33 05.92N 113 45 34.15W location is already posted up thread. Go direct to that comment by using this link:
http://www.kathrynsreport.com/2022/04/cessna-208b-grand-caravan-n928jp-fatal.html?showComment=1650113710197#c2541529799564513775
Sorry about the un-closed bold run-on. No preview function.
DeleteThanks for the correction, point taken. The plate shows 4,304 so I used that. Not sure why there's a discrepancy between the plate and the database (another FAA problem: which elevation, if either, is correct?). In any case, one shouldn't have to look up obstacles in a database and do trig on them to brief a plate. Main point is that a smokestack directly below and that close to the approach path is a really bad idea whether it's 61' or 109' because there's an inadequate safety factor. In this case, you have an unconventional approach angle, no vertical guidance, no VASI, no PAPI. You hit MDA, see the runway, and continue descent to land, but maybe don't see the smokestack due to snow flurries and steam from it blowing toward you. You don't have any vertical guidance at all, so if you're a bit low for whatever reason you don't know it... then you're dead.
DeleteNot sure what to say about plate interpretation, but what the pilot sees on flight displays is from a loaded copy of that electronic obstacle database, which is a good thing.
DeleteIt's true that 109' separation isn't a lot, but the outdated overhead view of the stack that google maps shows tends to make commenters here miss the red steel base structure and sampler's work platform at the very top in the more recent street view images. It's not just a pipe.
If the snow flurry intensifies or the tater drying plume is solid and significant such that it's going to have to be descended through or the combined conditions will be imposing loss of visual for a period of time after having sighted the runway at MDA, a go around is the correct response.
The accident pilot reportedly was not a first timer to BYI and for all of the NAVAID limitations you mentioned, a divert to Twin Falls (as had been done by whichever pilot was aboard on the day before the accident) was the choice to make if the visibility at the plant wasn't as reported by METAR during the two approach attempts.
As I mentioned in a comment above, the 4304' obstacle shown on the RWY 20 approach plate plan view is NOT any of the stacks at Gem State plant. It is this 140 foot radio tower near the United Metals Recycling plant, which is 0.6 NM north east of the Gem State stack :
Deletehttps://www.google.com/maps/@42.5584036,-113.7480359,3a,86.2y,335.86h,111.79t/data=!3m6!1e1!3m4!1sfD-logCbUr79CSW4DcVyPQ!2e0!7i13312!8i6656
Curiously, none of the Gem State stacks are notated anywhere on the approach plate. Either they didn't meet the criteria for inclusion or it was an oversight by the FAA.
Looking at obstacle markings on the BYI RW20 approach plate, it is interesting to compare to ALL of the HEYBURN-associated obstacles that exist in the current 16-ID.dat obstacle database.
DeleteNotably, the 4179' obstruction shown by the river at 7th avenue in the inset runway detail of the plate is not in the database, appears to be Gossner's Magic Valley Chalet based on low height and location. The four Gossner Foods elevators are not on the plate or in the database. This map-pin location is Gossner's Elevators:
maps.google.com/maps?t=k&q=loc:42.54918+-113.76041
Street view:
https://goo.gl/maps/2hJ8XhWHUTENBvEa8
Here are all of the HEYBURN obstacles of the 16-ID.dat obstacle database file, with map-pin and street view images after converting HH:MM:SS.SS GPS coordinates to decimal:
That 140 foot radio tower near the United Metals Recycling plant is:
16-022120 O US ID HEYBURN 42 33 31.30N 113 44 53.73W TOWER 1 00140 04291 N 1 D N 2020ANM06806OE C 2021126
maps.google.com/maps?t=k&q=loc:42.558694+-113.748258
#16-036731 is the crashed into stack, as already noted.
#16-036732 thru 16-036737 are 100', 4256' MSL Gem stacks:
maps.google.com/maps?t=k&q=loc:42.551047+-113.760189
And this 37' high tank is by the tracks at 7th Ave:
16-036750 O US ID HEYBURN 42 32 58.11N 113 45 47.84W TANK 1 00037 04187 R 4 D P 2017ANM00600OE C 2018029
maps.google.com/maps?t=k&q=loc:42.549475+-113.763289
Street view:
https://goo.gl/maps/zMVhwxePeR5Em32J7
Elevators 124' high, NorthEast of Gem:
16-000258 O US ID HEYBURN 42 33 17.33N 113 45 16.64W ELEVATOR 1 00124 04282 R 1 A N 0076_NW00104OE C 2013291
maps.google.com/maps?t=k&q=loc:42.554814+-113.754622
Street view:
https://goo.gl/maps/zRAEzTUpo3y2PpmJ6
But these across the tracks are not in the database:
https://goo.gl/maps/1ZD8aeGhy2Y1CsdEA
And this tower, Google maps doesn't show:
16-051497 U US ID HEYBURN 42 32 27.89N 113 45 01.48W TOWER 1 00125 04279 N 4 D N 2019ANM02334OE A 2020084
maps.google.com/maps?t=k&q=loc:42.541081+-113.750411
CALCULATE A VDP, use that DISTANCE FROM THE RUNWAY as a point to start down or go missed. This approach has an MDA of 408 AGL, a glideslope of 3.75, do the math. You take 400 divided by 375, you get 1.1 Miles from the runway as a VDP. A pilot can do a CDFA to the VDP, or "dive and drive" to the self-calculated VDP, either is legal, OK. But to go below the MDA prior to 1.1 miles from the runway kinda busts the approach. YOU DO NOT NEED TRIG OR OTHER BULL.
ReplyDeleteCouple years ago we hired an attractive young lady, a flight instructor, to fly Caravans at our single-pilot Pt.135 operation. Fourth or fifth day on the job, in good weather, she crash landed one of our 'Vans onto a runway, totally wrecking it. Fortunately, no one was hurt.
ReplyDeleteThe step up from the instruction/GA world to single-pilot 135 is huge. Many of these pilots require a certain amount of 'hand holding' before being turned loose on their own. They don't all get it.....
It sounds like your operation needs to improve its pilot evaluation, vetting, and training. Most of "those pilots" (as you call them) do just fine at almost all single pilot 135 operations and if they "don't get it", it's your job to weed them out. The single pilot 135 accident rate is actually much lower than the overall GA rate, despite the challenging conditions in which "those pilots" fly day in and day out.
DeleteInterpreting the original post can be taken as:
DeleteA: The pilots don't always get the necessary hand holding
-or-
B: The pilots don't get what flying is all about.
Seems like original post was A, response interpreted it as B.
Absolutely correct, our operation needed to improve its pilot evaluation, vetting and training. This issue was resolved by the pandemic, which put the company out of business.
DeleteHiring requires vetting and training. The process needs to be robust and agnostic in the person being hired. This mishap shows that regardless of who you are, physics and gravity and speed of impact are no respecter of persons. We keep killing ourselves for mostly the same reasons. "Nothing new under the sun." (or the overcast)
DeleteOh boy “ Couple years ago we hired an attractive young lady, a flight instructor” what does her looks have to do with being a pilot? Do you describe all your male pilots based on their looks?
DeleteFrom the preliminary ntsb report:
ReplyDelete"According to a witness, located about one quarter mile away, he first heard, then observed the airplane descend out of the clouds then immediately went into a steam cloud, which was produced from a set of six smokestacks located on the same roof. The witness heard the engine increase in sound and saw the nose lift shortly before the airplane struck the smokestack and descend to the rooftop."
This means the potato plant created artificial IFR conditions. The lawyers are going to have a field day with this one.
DeleteThe location where the witness was viewing from is a significant factor for interpreting what is reported as seen.
DeleteA viewpoint location one quarter mile (1,320 feet) toward the airport from the stack (such as at Gossner's areas adjacent to 7th Avenue) would be very likely to see the approaching aircraft appear to descend into the water vapor plume, but viewpoint locations off to the side of the flight track or Northeast of the stacks have a different perspective.
Plant has operated since 2011, so there has been a long period of opportunity where the water vapor plume from the dryer stacks were operating under similar weather conditions and subject to observation, photos and videos of plume behaviour in all wx conditions.
Potato plant created artificial IFR conditions! will certainly be the tuber rallying cry long before witness location is publicized, plume data presented or VDP and MDA considerations are resolved, but that's just how everyone rolls in pursuit of views and outrage these days.
The wind at the time of the crash was just so that the steam plume was pushing right down the line of the runway. Steam has water vapor and is warm so it provides significantly less lift. She applied power and nose up to go around but the steam cloud pulled her right into the stack.
DeleteOr maybe you're smarter than the ntsb investigators right there at the scene interviewing witnesses and looking at the weather conditions and the runway and what happened? Give it up, she didn't bust minimums she got sucked right into that smokestack by the steam cloud she couldn't get out of in time.
This is 100% on the potato plant
"Sucked right into that smokestack by the steam cloud!" is quite a claim. If it was sarcasm, you should include /s so people don't mistake it for a serious reply.
DeleteCalculations of how much mass of water vapor was being delivered by the stacks and mixed into the air above the plant, with diffusion, spread and distance of the effect from the point of emission weren't in the preliminary.
Not sure why there would be a belief that the preliminary indicates that investigators have settled on "sucked down" as the cause, but that type of weird phrasing is typical tuber fandom carryover as mentioned in the post you responded to, proving the point perfectly - Thanks!
"Calculations of how much mass of water vapor was being delivered by the stacks and mixed into the air above the plant, with diffusion, spread and distance of the effect from the point of emission weren't in the preliminary."
DeleteThe NTSB never includes detailed calculations in the preliminary. They just list basic facts and observations with occasional cursory analysis. I can attest to having my aircraft rocked by turbulence simply from the warm air currents gently rising from a dark field, so I have no doubt that a concentrated column of moist hot air being spewed out of a row of smokestacks could have a very serious effect on a light aircraft. It wasn't so long ago that people underestimated the serious effects of wake turbulence as well. I guarantee that the energy output that industrial plant is emitting into the atmosphere would rival the output of any heavy category aircraft.
"typical tuber fandom". Tubers meaning starchy root vegetables like potatoes? So the potato plant has their own fan club that is going to come to their defense if they get blamed for this crash? LOL
Whatever the case, it's clear from the NTSB report that the mob that was fixated on "busted minimums" was wrong. Yes, the pilot descended below minimums but she did so because she had the runway in sight, which is NOT a minimums "bust". If she was still in IMC after minimums, the witness and security camera would not have seen her aircraft.
This is typical and one of the worst aspects of this community. The criticism of the deceased pilot rages on well before the preliminary is released and facts are obtained, and usually before the deceased has even been buried.
DeleteI am all for accident analysis and understanding what went wrong in the name of preventing future occurrences - and boy does this case fit the bill - but our online aviation community (which unfortunately includes non-aviators) is swift to judge with limited information, a dangerous tendency in and of itself. The people most hurt by these comments, at what is often the worst time of their lives, shouldn’t have to see baseless or inaccurate opinions of strangers about why their loved one is gone.
And I wonder how many actually follow up on final reports - as in reading the full final docket - to understand the real-life nature of how the holes in the cheese line up.
Condolences and humble prayers to Brittney’s family and kin. She sounds like a bright individual gone too soon. Rest easy.
Watching dockets and following up can reveal that as much as everyone hopes otherwise, pilot decision making really was the undoing.
DeleteThe CVR transcript has finally been placed in the docket for the November 30, 2019 crash of N56KJ in Chamberlain. The real-life nature of what transpired reveals a complete pilot disregard for a multitude of no-go factors and specifically communicated warnings.
https://data.ntsb.gov/Docket/Document/docBLOB?ID=13775462&FileExtension=pdf&FileName=CEN20FA022_CVR_Report_RELEASE-Rel.pdf
Docket:
https://data.ntsb.gov/Docket?ProjectID=100636
Thanks for posting that CVR transcript. I just read it and yikes! When the airport manager says things to you like "it don't look good to me I don't know what you guys are thinkin'." and "you guys are crazy", maybe pause what you are doing and reconsider. Too bad comments on here are closed for that accident.
DeleteYes, the N56KJ CVR transcript and the fact that the top of the tail was not cleared because "it will blow off" are important reminders of how far you can go wrong with decision making focused toward get-there-itis.
DeleteHaving comments on N56KJ closed is unfortunate. The fully revealed circumstances are a huge cautionary tale. Surprised to see videos in the docket by astonished onlookers in disbelief that there would be a takeoff.
Sometimes KR will re-post when new info comes out. Maybe there could be a re-post with an explanation that new commenting is closed out of respect for survivors but final docket and CVR content is important to communicate for education and awareness.
There is no need to conflate the egregious errors in the case of N56KJ. If you want to talk about it, post there or POA. What does this flight have in common other than Idaho residents?
DeleteThe point is there are numerous comments disparaging this accident pilot for busting mins despite not fully understanding the situation, and its unwise, unhelpful, and hurtful to many to spread uninformed none sense.
Also, if we’re going to go there, I’d go as far as to say most all were incorrect as to the cause of the incident of N56KJ. Despite the terrible ADM, it was a common act of poor airmanship (yoke yanking, early rotation) that induced the incident as noted in the very detailed case study. Amazingly, the flight could have succeeded all things else considered.
The onus would appear to be on the plant and surrounding politics in this instance. Nevertheless, RIP to Brittney and condolences to her family and friends.
You have to wonder if the plant would be blamed so vigorously in its 11th year of 24 hour drum dryer operation if N928JP's pilot was someone else.
DeleteSomeone else who had similarly flown into BYI many times, made a first approach across the impossible to overcome steam cloud before going missed, came in for the second after sizing it all up thoroughly on the first pass, but continuing until crashing instead of going missed again.
Someone who kept risking it that day in spite of the aircraft diverting to Twin Falls the day before, which suggests that the freight company could deal with handling the 30 mile location shift of freight delivery/pickup for the more sensible divert away from the impossible to overcome steam cloud.
If it doesn't turn out to be the impossible PT-6 failure or impossible pilot PT-6 misoperation, then all that remains is pilot error from risking the impossible to overcome steam cloud that had just been flown over and had a good look at on the first approach, hoping against hope that it wouldn't be impossible to overcome this time.
Letting the video channel guy assign the impossible to overcome steam cloud as the certain to be true cause has replaced his prior assignment of the "intentionally busted minimums" story to the minds of easily influenced followers.
People have certain biases from who was flying in any accident that makes it easy to manipulate them. They won't believe it if NTSB doesn't blame the impossible to overcome steam cloud in the final a couple of years hence.
For lost lift or turbulence from stack vapor plume as the cause of the crash, the obvious next question is why the first approach that went missed didn't include a crash into the plant from the effects that brought the Caravan down on the accident approach.
ReplyDeleteWhat was different?
Looking at three first approach data points in sequence, two of which were located before reaching the Gem plant and a third beyond BYI, with locations map-pinned for viewing, the difference shows up as ground speed much greater during first approach:
Wed 10:11:37 AM 42.5614 -113.7494 ↙218° 133 153 4,625 -913
http://maps.google.com/maps?t=k&q=loc:42.5614+-113.7494
Wed 10:11:53 AM 42.5532 -113.7580 ↙217° 128 147 4,375 -128
http://maps.google.com/maps?t=k&q=loc:42.5532+-113.7580
Wed 10:12:59 AM 42.5277 -113.7819 ↙207° 93 107 4,450 192
http://maps.google.com/maps?t=k&q=loc:42.5277+-113.7819
That raises another question:
After having flown that first approach and experiencing the vapor plume, why was the second approach ground speed reduced to 81/80 knots from the first approach's 133/128 knots coming toward the Gem plant? (Note: BYI METAR winds were 200° at 7 to 8 knots during both approaches.)
Would a C208 pilot purposely establish/maintain the almost 50 knot slower accident approach speed after encountering the plume on the first approach?
Easy to answer. The pilot went around on the first approach well before reaching the stacks and also at over 200 feet higher. It's likely the effect of the plume is fairly localized, much like wake turbulence. If the plume broadly affected approaches, this wouldn't have been the first occurrence. Also, if the pilot intended the first pass to inspect the runway surface and conditions, they would not have slowed down as much as on the final pass. Or maybe the pilot went around on the first pass *because* they were carrying too much speed.
DeleteGood observation about first occurrence. Plant info says it operates 24 hours, has been in operation since 2011.
DeletePresumably the NTSB is evaluating appropriate airspeed for the accident day combination of two approach exposures to potential mist and light snow airframe ice contamination, considering the minus 3 C / 27 F temperature reported at the airfield.
As-flown airspeeds of two different freight company C208's approaching the Gem stacks are interesting to compare.
N585SA BYI RW20 C208 VFR approaches:
4/15/2022 120 knot GS + 27009KT wind component
4/26/2022 096 knot GS + 22011KT wind component
4/27/2022 127 knot GS + 28005KT wind component
N928JP BYI RW20 C208 VFR approach:
4/04/2022 083 knot GS + 22009KT wind component
N928JP BYI RW20 C208 IMC approach w/crash:
4/13/2022 081 knot GS + 19008KT wind component
That's too slow. Usually when someone does that in a 'Van it's with 20 or full flaps, in the hope of 'parachuting' the plane down to the runway, then adding a touch of throttle just before touchdown.
Delete4k hrs. in 'vans, always used about 95 Kts on short final, slowing to 80~85 just before touchdown (depending on load, winds, etc.).
when you can see the ground below you and the runway end ahead you are going to adjust rate of decent so as to hit the piano keys. apparently it was marginal vfr below an overcast with one mile vis. except for a steam cloud that probably obscured some smoke stacks and towers. it seems to me she became visual at or near the dh and continued the approach visually. but the sight picture she had of the runway end brought her into the steam cloud. i blame it on the steam cloud.
ReplyDelete"blame it on the steam cloud" assigns no responsibility, no liability. Steam clouds exists because of gov't and corporate decisions, made by corporate executives and gov't officials.
ReplyDeleteI want to add some info here, for what it's worth. I'm not a pilot. I'm an engineer and have a bachelor's degree in mechanical engineering and a master's degree in aerospace engineering, with 15 years experience.
ReplyDeleteUsing satellite data from Google Earth, I drew up the geometry of this airport and the surrounding area in CAD, to prevent math errors. I will give the details below for others to replicate, but here are my conclusions:
(1) If you start at 4800ft at JAMID, and then descend with a 3.75 degree angle from horizontal as advised on the published approach plate, you would clear the top of a 100' AGL stack by only *63 feet.*
(2) If you back-solve this the other way, starting from the end of the runway with a 40ft TCH vertical offset as shown on the published plate, and go up toward JAMID with a 3.75 degree slope, you still only clear the top of a 100ft AGL stack by *73 feet.*
That's very little margin for error, and that's following the published approach on the plate. Now factor in the possibility of wind, turbulence, or lift disturbances when the steam cloud was entered, plus the stack being totally obscured by its own steam cloud, and boom, you've hit that stack. From the eyewitness testimony in the preliminary report, we know the she did enter the steam cloud.
As for the MDA, if she had the runway in view (and likely did at this range, as the forward visibility was given as 1 statute mile, she was already below the cloud base, and the stack is almost exactly 0.5 mi from the threshold of the runway), she was ok to be below MDA.
I also want to emphasize that the impacted stack is DIRECTLY on the extended centerline of the runway. Dead-center. Others in earlier comments cited an obstruction of 60ft AGL with a lateral offset from the centerline, but that is *not* the stack that was hit.
Here are the numbers I used in arriving at the above conclusions:
(1) Runway displaced threshold length = 305.7ft (measured from satellite data)
(2) Distance from runway threshold to impacted stack = 2633.4 ft (measured from satellite data)
(3) Distance from runway threshold to JAMID = 1.6 NM (9721.8 ft) (on published approach plate)
(4) Altitude when crossing JAMID = 4800 ft (on published approach plate)
I included the 40 ft TCH elevation offset from the approach plate in my conclusions above.
Assumptions:
(a) Assuming the ground surface elevation at the potato plant is 20ft above the runway TDZE. This is from the elevation data in Google Earth, and visually looking from the runway appears to be in the ballpark, as the northeast bank of the river is higher than the runway.
(b) Assuming the stack is 100ft AGL, from the ground surface elevation at the plant. Thus, the top of the stack would be 120ft AGL relative to the runway threshold, due to the first assumption.
Why assume a or b? Stack is 100' AGL, 4,256' MSL per the obstruction database:
Delete16-036731 O US ID HEYBURN 42 33 05.92N 113 45 34.15W STACK 1 00100 04256 R 4 D P 2016ANM01617OE A 2017285
Full stack database discussion here:
http://www.kathrynsreport.com/2022/04/cessna-208b-grand-caravan-n928jp-fatal.html?showComment=1650113710197#c2541529799564513775
Hi, thanks for the info and the link. I listed them as assumptions because I considered the info unverified until we get confirmation of a measured stack height.
DeleteIf the FAA obstruction listing is correct, that means ground level at the potato plant is only 4 feet higher than TDZE (4256 - 100 - 4152 = 4 feet). But looking northeast toward the plant from the end of RWY20, the elevation difference on the opposite bank appears to be a lot more than 4 feet. The elevation data in Google Earth also does not agree with a 4' difference. It shows the end of RWY20 as 4143' at the threshold, and 4160' on the ground beside the potato plant. I do realize the Google Earth data might not be exact, but it's even showing the small drop at the precise edge of the riverbank, so I'm inclined to believe it might be valid, at least for relative elevation differences.
At any rate, if the FAA obstruction listing is accurate, that only adds 16' of extra vertical margin to the clearances I wrote above. I would really like to see some *measured* data of the actual height of that tower before it was razed, as well as its MSL elevation. With such small margins, even little differences count.
I came to the same conclusion using approach plate data and Google Earth. The collision smokestack is directly on centerline. If you're below the unusually steep 3.75 degree approach angle and it's obscured by its own steam, you're gonna hit it. There's no way to verify that your approach angle is correct because there's no vertical guidance nor is there a PAPI or VASI on that runway. Can't imagine why this approach is even published. there's no margin for error.
DeleteMy previous post - http://www.kathrynsreport.com/2022/04/cessna-208b-grand-caravan-n928jp-fatal.html?showComment=1650993837300#c308390018535584787 I
You are a good sport to allow me to reference the database record and dangle the alluring suggestion that the FAA obstruction record is more accurate than your assumptions.
DeleteFor a moment let's adjust your pass-over clearance results of 63' and 73' up by that extra 16 feet to get 79' and 89' pass-over clearances while pretending that the FAA database numbers are spot on (read on for the surprise!).
Although there is not likely to be an easy way to know what google tolerance/accuracy is, my posting of the obstruction database for that stack referenced a pdf for decoding the raw record, which includes how to decipher the declared accuracy of the "verified" FAA obstruction info.
(Nobody commenting here so far has indicated that they looked closely and noticed the tolerance associated with specific obstruction records in the obstruction database, so it's time to shine a light on declared tolerances there.)
The record again, now with tolerance codes highlighted:
16-036731 O US ID HEYBURN 42 33 05.92N 113 45 34.15W STACK 1 00100 04256 R 4 D P 2016ANM01617OE A 2017285
For stack 16-036731, code "D" means that the declared accuracy of the recorded vertical information in AGL and MSL is +/- 50 feet, which for a 100' stack is an absurdly large tolerance.
The lateral accuracy code "4" makes the horizontal tolerance of the location +/- 250 feet. Verifying that it is the correct stack by mapping the stack coordinates is somewhat of a leap of faith.
Let's now work from the 79' and 89' clearances we got from adjusting your calcs by pretending that the nominal FAA elevation numbers were accurate. Applying the full +50 feet of declared tolerance to 100' AGL and 4,256' MSL takes 50 feet out of the 79' and 89' foot clearance numbers leaving pass-over clearances of just 13 and 23 feet.
What a can of worms. The obstruction database tolerance codes need to be audited in every record to see if declared accuracy limits are being applied to obstructions in approach and departure surface profiles or just the nominal stated elevations are being used.
For convenience, here is the decoder link again, with info on decoding the data record starting on the readme pdf's page 5:
https://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dof/media/DOF_README_09-03-2019.pdf
^^ Messed up my numbers, 13 and 23 feet should be 29 and 39 feet of pass-over clearance.
DeleteApologies, was a long screed to check...
Forget all the right triangle calculations for a moment and think of this; The pilot was flying 70 to 75' agl, 2500 feet from the threshold. Do that at many many airports and you'll probably hit something. There are no obstruction clearance guarantees below the MDA.
DeleteCmores comment= enough said- til more is known. Succinct. (Although it is interesting to speculate, and discuss.)
DeleteDG posted an hour long analysis of this accident on his channel. Interestingly, he showed FAA correspondence admitting that the plant stacks penetrated the approach surface. He also attempted to do a recreation of the approach into KBYI by scud-running with a non-IFR rated pilot, seemingly violating cloud clearance requirements and also not making any calls on the CTAF frequency during his approach. https://flightaware.com/live/flight/N2217R/history/20220508/1750Z/KTWF/KTWF We are lucky there wasn't a second accident at KBYI!
ReplyDeleteShowing those documents as full sheet images before zooming in to a cropped section would be best. The documents could also be provided on the DG website he operates so that anyone can see them in full context. Doing so would eliminate suspicion that there might be cherry picking going on. Easy enough to black out signatures.
DeleteWas he given permission to take that marker light?
You wouldn't think that an expert would expect a strobe light instead of the red marker to be placed that close to the airport, given the easy to find advisory circular guidance, as noted in a previous comment:
http://www.kathrynsreport.com/2022/04/cessna-208b-grand-caravan-n928jp-fatal.html?showComment=1650238952384#c1446716018867091538
Excellent comment. I noticed Dan's poor comm skills also and the pilot's incorrect read backs.
DeleteThen to prove how dangerous the LNAV +V approach is, they fly it high, seemingly to prove how the advisory glide slope dragged the 208 down in to the tower.
Suggest you do a little searching for DG's past history/reputation. It is easily found on the Internet.
DeleteWith airlines short of pilots, why was this 30 year old college grad "COMMERCIAL PILOT Date of Issue: 1/3/2020" flying UPS 208 Grand Caravans? Lack of hours?
ReplyDeleteRatings: COMMERCIAL PILOT
AIRPLANE SINGLE ENGINE LAND
AIRPLANE SINGLE ENGINE SEA
AIRPLANE MULTIENGINE LAND
INSTRUMENT AIRPLANE
1500hr rule. She was just building hours waiting to get on with a regional. Really, really nice woman and safe pilot
DeletePilot's father says she flew to this airport all the time and was well aware of any obstacles. Made a first approach over the known obstacles that revealed the circumstances of what is being portrayed as dangerous wall of steam but didn't divert after going missed from the first approach.
ReplyDeleteWhy not divert and avoid the known and just-previewed danger?
Looking at known and possible "Not diverting this time" bias factors:
- Known bias factors:
1. The previous day's BYI flight diverted to Twin Falls.
2. Freight repositioning on ground after divert adds cost, hits schedule.
3. Yesterday's divert impact/scramble is fresh in pilot's mind.
4. Yesterday's divert impact/scramble is fresh in dispatcher's mind.
- Possible bias factors:
5. All: "Diverting today is less justifiable, weather is not at minimums"
6. Other company pilots: "BYI steam is routine, I can land there just fine"
7. Company dispatcher: "Our other pilots could have landed BYI today"
8. Accident pilot: "I have to meet expectations and get this done"
Interesting article reflecting on "completing the mission":
https://www.aviationsafetymagazine.com/features/decision-making-for-pilots/
Well-stated, very good bias what-if scenario.
DeletePhoto of N 928JP is still up on GEM AIR's web site. https://gemairflights.com/
ReplyDeleteI read all the comments. There is a lot of emotion in this thread. When I read about these tragic accidents, I try not to search about personal life of the pilot, look at photos with family... Sometimes it's relevant to the accident but most often than not, it just adds a layer of emotion that I can do without.
ReplyDeleteWhen I look at this story, I tend to reason backwards: the Caravan hit a stack. That's the only certainty we have at this stage about its position. We also know that this position was too low as thousands of other flights landed on that runway without hitting the stack.
The MDH seems much lower than the OVC layer. It seems very likely that the Caravan was out of the clouds well before reaching the MDH. This is probably why the pilot decided to continue the approach.
It was snowing at the time and snow showers would've probably reduced visibility. At that point, runway or runway lighting were visible but not necessarily the thin grey stack in between. At that point, the pilot would be using external visual references or at least trying to.
During that last phase, the Caravan was in a nose-high descent. That, combined with the snow, make it difficult to (1) visually appreciate the actual descent path being flown and, (2) see obstacles that are just protruding in the aforementioned path.
As the Caravan started overflying the Gem factory, visibility further degraded due to the steam pulsed from the 6 stacks. Wind coming from 190 to 210 and the runway being on the 202, it necessarily follows that any plane flying that approach will be in the steam at one point.
This is when the pilot lost visibility and decided to go around. A witness quoted by the NTSB heard the engine noise increasing just prior to the impact.
RIP.
^ You are making too much of a simple accident.
Delete^^ Exhibiting garrulous behavior.
DeleteDoesn't make sense to say "I read all the comments" and then talk about runway lighting when comments upthread established that the crash at 8:32 AM was an hour and a half after the 6:56 sunrise.
Delete"It seems very likely that the Caravan was out of the clouds well before reaching the MDH. This is probably why the pilot decided to continue the approach"
DeleteThe eye witness account does not agree with your theory. I think the witness is correct, based on my calculation as follows...
The ASOS reported 1SM visibility. The ASOS facility is located 600' west of the runway 20 threshold, so I think the Caravan would have broken out approximately 4650' from the runway and just 2100' from the stack that was hit. If the pilot was following the 3.75 deg. advisory GS, that would have put her 50-60' below MDA. At ground speeds reported, that was only 16 seconds from breaking out of cloud, to reaching the stack. Average descent angle was 9.2 degrees, or a loss of 350' in those last seconds, but the approach seemed unstable from JAMID. The witness has the Caravan coming out of the clouds, then very quickly entering the steam produced by the stacks, right before the collision.
@Cmor - Using 1 mile visibility was incorrect in your reply to that commenter.
DeleteThe 14:25Z AWOS report of 1 1/2SM visibility is displaced 5,260 feet toward the aircraft by the time the aircraft came into view of the camera at Gem more than 7 minutes later at 14:32:25 if you are applying the 7 knot wind as positional displacement downwind based on time elapsed after individual AWOS condition reports.
1425Z AUTO 20008KT 1 1/2SM -SN BR BKN021 OVC028
AWOS shows 1SM, 1 1/2SM, 2SM visibility progression:
KBYI 131420Z AUTO 20007KT 1SM -SN BR BKN021 OVC026 M03/M06 A2997
KBYI 131425Z AUTO 20008KT 1 1/2SM -SN BR BKN021 OVC028 M03/M06 A2997
KBYI 131430Z AUTO 20007KT 2SM -SN BR BKN021 OVC028 M03/M06 A2997
I got my info from The NTSB preliminary report, WPR22FA151:
DeleteA special automated weather report for BYI about the time of the accident reported 1 mile visibility in light snow and mist, broken layer at 2,300 ft above ground level (agl), overcast at 2,800 ft agl, temperature -3°C, dew point temperature -5°C, barometric pressure 29.96 inches of mercury. An Airmen’s Meteorological Information (AIRMET) advisory was active for icing and mountain obscurations for areas that included BYI.
By the way, the automated weather facility at KBYI is an ASOS, not AWOS.
AWOS data typically includes ceiling and sky conditions, visibility, temperature, dew point, altimeter setting and wind speed, gusts and direction, ASOS can additionally provide the type and intensity of precipitation (rain, snow, freezing rain), and obstructions to visibility such as fog and haze.
If you understood how preliminary reports record meteorological information in the report format, you would have looked at the time of the observation, as recorded on page 2 in the "Meteorological Information and Flight Plan" block:
DeleteObservation Facility, Elevation: KBYI,4143 ft msl
Observation Time: 08:10 Local
It should be obvious now that the calculations you made used an observation from 22 minutes prior to the accident. The observations reported at 14:20, 14:25, 14:30 of 1SM, 1 1/2SM, 2SM visibility invalidate calculations made using 1SM visibility.
Original report link:
https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104938/pdf
Anonymous, if the visibility was as good as you say it was, why did the pilot hit the tower?
DeleteIf the visibility was .5 SM better than reported, then the pilot would have had approximately 35 seconds from breaking out to see and avoid the tower.
Before the first approach, the pilot acknowledged the weather. There is no indication as yet that the pilot was given the special automated report. Nevertheless, based on the actual weather, security video and eye witness report, the visibility was 1SM at the time of the accident, giving the pilot only 16 seconds from breaking out, to react before hitting the tower.
Since the pilot was already below the MDA in IMC, the combination of snow, cloud, the steam plume, low flight altitude (75’ agl), did not allow her to see and avoid the tower.
“A review of air traffic control (ATC) communication with the pilot revealed the approach controller issued the pilot the current altimeter setting and verified that the pilot had the current weather and notices to airmen reports for BYI.”
“A special automated weather report for BYI about the time of the accident reported 1 mile visibility in light snow and mist…”
“Video footage recovered from a security camera located on a processing plant revealed a view of the rooftop of the processing plant, along with a smokestack supported by steel framework on the roof. Snow was observed falling. About 0832:25, the airplane came into view…”
“According to a witness, located about one quarter mile away, he first heard, then observed the airplane descend out of the clouds then immediately went into a steam cloud, …”.
Discussion has returned to "the pilot was willfully continuing far below MDA of 4560 and couldn't see". If so, should have gone missed a second time.
DeleteBurley is considering a new airport location:
ReplyDeletehttps://www.idahostatejournal.com/news/local/burley-ready-to-move-forward-with-new-airport-project-asks-counties-for-support/article_5a0c977c-3015-5dec-bd16-35979dfa8cdf.html
This is probably the hardest commercial flying job around
ReplyDeletePilot is the third most dangerous job.
Fatal injuries per 100,000 full-time equivalent workers: 58.9
https://www.cnbc.com/2019/12/27/the-10-most-dangerous-jobs-in-america-according-to-bls-data.html
Renowned airshow performer Eric Beard also died as a freight dog pilot.
https://archive.seattletimes.com/archive/?date=20060108&slug=webpilot08
YouTube https://youtu.be/LivNwDABHdw
NTSB https://generalaviationnews.com/2006/09/22/ntsb-cites-pilot-error-in-january-airpac-crash/
What a dumb place to put the potato factory, lots of open land, but yeahhh let’s put factory with stem stacks right on short final. Wonder who got paid off to approve that nonsense building permit.
ReplyDeleteThere are many approaches just as challenging, that's why you respect the MDA and you do not descend unless the runway is in sight. The pilot made the processing plant a problem by being in IMC, 75' agl 2500' from the runway threshold.
ReplyDeleteSad, but True ...
Deleteit seems you haven't even bothered to read the prelim report. i suggest you read it, and digest it. She descended out of the clouds and was quickly enveloped in the steam cloud (as witnessed by people on the ground and by surveillance video). The steam cloud has little to no lift. If you were a pilot you would know that warm/wet air has very little lift. She went full power and could not arrest her descent and hit the stack. Please stop commenting on things you don't even comprehend or until you bother to understand the known facts
DeleteShe was so young and beautiful and now she is gone. MDA's are there for a reason. I bet that last moment of reality was shocking. I am sorry she killed herself and thankful she did not injure or kill anything else.
ReplyDeleteHer life was not any more valuable because she was pretty. A pilot is a pilot and she made a mistake and hit something she knew was there.
DeletePlease keep in mind, comments on tragedies like these sometimes come from, and are seen by, people who knew them. Her life was extremely valuable to her many friends and family. Always remember the human side, and respect that a lot of people suffer greatly from a loss like this.
DeleteIf she didn't hit the tower, she would of hit the parking lot. She was descending at 700 / minute. The tower was 60 agl
ReplyDeleteAmen
Deleteshe lost altitude quickly when she hit the steam cloud. no lift in warm/wet steam. she went full power and still couldn't climb out of it. she didn't fly into the stack, the steam cloud sucked her right into it by taking all her lift away
DeleteMust have been one hell of a steam cloud....
ReplyDeletesteam coalescing from 6 stacks into one plume, per NTSB report
DeleteOK...there might have been steam from the various stacks on the building, but the conditions were IMC from below the MDA, all the way to breaking out a few seconds before hitting the tower. Rule is, you don';t go below the MDA unless the runway environment is continuously in sight and for the Caravan pilot, it was not. Operate below MDA at your own risk..
DeleteFor one ADSB tracks are not reliable, for two how incompetent of .gov to put a stack right on short final
ReplyDeleteThe stack would not have been hit had the pilot not busted minimums and gone below the MDA. What does ADSB have to do with this preventable accident?
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