Thursday, April 14, 2022

Cirrus SR22, N112TR: Accident occurred April 13, 2022 in Twin Lakes, Lake County, Colorado

This is preliminary information, subject to change, and may contain errors. Any errors in this report will be corrected when the final report has been completed. 

The National Transportation Safety Board did not travel to the scene of this accident. 

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Denver, Colorado
Cirrus Aircraft; Duluth, Minnesota 

Tango Tango Romeo LLC


Location: Twin Lakes, Colorado 
Accident Number: CEN22LA176
Date and Time: April 13, 2022, 07:04 Local 
Registration: N112TR
Aircraft: CIRRUS DESIGN CORP SR22
Injuries: 1 Minor
Flight Conducted Under: Part 91: General aviation - Personal

On April 13, 2022, at 0704 mountain daylight time, a Cirrus Design SR22 airplane, N112TR, was substantially damaged when it was involved in an accident near Twin Lakes, Colorado. The pilot sustained minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

Automatic Dependent Surveillance – Broadcast (ADS-B) data depicted the airplane depart the Grand Junction Regional Airport (GJT) at 0621. The flight proceeded southeast before it turned east-northeast and climbed to flight level 210. At 0658, the pilot informed air traffic control of a loss of engine power.

The pilot’s efforts to restore engine power were unsuccessful and he deployed the Cirrus Airframe Parachute System (CAPS) at 0702.

The airplane came to rest upright in a mountain valley. The accident site consisted of rocky terrain with low brush. The fuselage and wing spar were damaged during the CAPS assisted touchdown.

Post-recovery airframe and engine examinations are planned.

Aircraft and Owner/Operator Information

Aircraft Make: CIRRUS DESIGN CORP 
Registration: N112TR
Model/Series: SR22 
Aircraft Category: Airplane
Amateur Built:
Operator:
Operating Certificate(s) Held: None
Operator Designator Code:

Meteorological Information and Flight Plan

Conditions at Accident Site: VMC
Condition of Light: Day
Observation Facility, Elevation: KLXV,9943 ft msl
Observation Time: 07:03 Local
Distance from Accident Site: 8 Nautical Miles
Temperature/Dew Point: -14°C /-17°C
Lowest Cloud Condition:
Wind Speed/Gusts, Direction: 5 knots / 0 knots, 340°
Lowest Ceiling: Overcast / 2900 ft AGL
Visibility: 0.75 miles
Altimeter Setting: 29.71 inches Hg 
Type of Flight Plan Filed: IFR
Departure Point: Grand Junction, CO (GJT)
Destination: Englewood, CO (APA)

Wreckage and Impact Information

Crew Injuries: 1 Minor
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A 
Aircraft Explosion: None
Total Injuries: 1 Minor
Latitude, Longitude: 39.094174,-106.36934

Aircraft lost engine power, deployed parachute. 

Date: 13-APR-22
Time: 12:50:00Z
Regis#: N112TR
Aircraft Make: CIRRUS
Aircraft Model: SR22
Event Type: ACCIDENT
Highest Injury: MINOR
Aircraft Missing: No
Damage: SUBSTANTIAL
Activity: PERSONAL
Flight Phase: EN ROUTE (ENR)
Operation: 91
City: TWIN LAKES
State: COLORADO

9 comments:

  1. 12:57Z cruising "Groundspeed: 201 kt Baro. Altitude: ▲ 23025 ft Geom. Altitude: 22225 ft Vert. Rate: 384 ft/min Track: 75.9°" Pos.:39.015°, -106.580° when the engine apparently quit.

    13:03Z last return
    Groundspeed: 12 kt
    Baro. Altitude: on ground
    Geom. Altitude: 14100 ft
    Vert. Rate:-1984 ft/min
    Pos.: 39.095°, -106.374°

    ReplyDelete
    Replies
    1. Ugh, rather than posting random points, here is the whole track so everyone can look for themselves: https://globe.adsbexchange.com/?icao=a0355a&lat=39.027&lon=-106.408&zoom=11.4&showTrace=2022-04-13&trackLabels

      Heck of a place to lose your engine surrounded by peaks as high as 14,433

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    2. Air being less dense at 14K presumably yields a higher impact speed for the chute than reaching ground at sea level. Has anyone done the calculation? Inquiring spines want to know..

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    3. No expert, but dynamic pressure, which in this case is the force per area (shute area) "pushing" against the force (= mass(weight) * acceleration (g)) of the falling plane, is 1/2 v^2 * density.
      In other words, at half the density (that would be at 18,000 feet) the speed needs to be ~1.4 times (square root of 2) higher for the same dynamic pressure, so at bit less than 1.4-times faster at 14,000 feet.
      Air density/pressure is not linearly decreasing with altitude (unlike water when diving) because gases are compressible, meaning the exact factor for 14,000 feet is a calculation I cannot do in my head while writing this.
      Tailwinds!

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    4. Thanks for the response, will have to settle for a hypothetical. :-)

      Putting Gas Law aside, the unspecified for 14K MSL (but a little bit faster) chute descent suffers from the square term for energy carried into ground impact. Making a relative comparison of energy at two speeds only requires evaluating the square of the speed term in order to be informative of the difference.

      Two unverified on-chute Cirrus descent speeds returned by casual search are 22 and 28 feet per second. 28 feet per second is six feet per second faster that 22, which is 6/22 x 100 = 27 percent speed increase over 22 fps.

      Looking at the energy equation square term:
      22 x 22 = 484
      28 x 28 = 784
      784 is 300 units more than 484. 300 units is 300/484 x 100 = 62 percent higher energy than impacting while at 22 feet per second.

      It would be interesting to know the official descent velocities from Cirrus for chute landing (of equivalent weight/loaded aircraft) to both a sea level and 14K MSL location. Not a criticism, just curiosity...

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    5. I wrote the above answer but have no idea what you are talking about.
      The question (was that you?) was about impact speed, not "energy carried into ground impact", which has everything to do with the combined gas law as well as the dynamic pressure equation I provided (without any coefficient) to close in on an answer and doesn't suffer from a square term.
      Your calculation of said square term from the two published descent speeds is cumbersome as you already calculated a 27 percent increase in speed and simply square 1.27 to get to ~1.62 instead of the detour with 300/484.
      I can only hope you are clearer and straight forward when flying.
      There are probably other factors at play like angle of attack of the chute (not shite as I misspelled) and chute design features i simply have no idea about.
      Tailwinds

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    6. Sorry that you reacted negatively to the thank you by perceiving the response as criticism, it was not intended to be perceived that way. Appreciation of your reply included not replying with snark for the spelling of shute area since your intent there was clear.

      Comparing energy to be dissipated upon ground impact at differing descent velocities was the purpose of posting the original question about speed on the chute.

      You would know that energy of mass in motion is 1/2mV^2

      For the purpose of discussion, calculating the percentage change between two velocities and then similarly presenting the percentage change for two associated energy calculations was just a step by step presentation choice intended to make it easy for anyone to follow.

      Regarding perceptions while online:
      Communication misunderstandings are unfortunate but not uncommon. The most enduring example from my own experience came from this statement offered to supervisors by a manager as advice to supervisors that reported to him:

      "Always share credit, never share blame"

      The manager intended to convey the principle of making sure that those who were supervised got the credit they deserved and not be blamed.

      But the manager had a legendary reputation of taking credit for work he had not contributed to and he always avoided taking responsibility for his own errors.

      The supervisors left the meeting shocked in their perception that the manager had openly advocated taking credit for other people's work and not taking on any blame yourself, because they knew the boss conducted himself in exactly such a manner in his dealings with the supervisors.

      In spite of his flaws, that wasn't what the manager intended to convey. A substantial amount of conflict and misunderstanding seen online suffers similar unintended misperception made worse by the limitations of text based asynchronous comment exchange.

      Offering a hypothetical energy comparison was not done as snark to your reply. Still interested in seeing useful calculations for chute landings at both elevations.

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    7. ^^ Unintended runaway italics after the managers statement. Sure do miss the preview function... :-)

      Delete
  2. METARs for Leadville airport at the time:

    KLXV 131212Z AUTO 35009G15KT 3SM -SN BKN018 M14/M17
    A2970 RMK AO2 P0001 T11391167
    KLXV 131232Z AUTO 33005KT 10SM FEW016 BKN070 OVC100 M14/M18
    A2970 RMK AO2 SNE17 P0001 T11391178
    KLXV 131303Z AUTO 34005KT 1 3/4SM -SN OVC029 M14/M17
    A2971 RMK AO2 P0000 T11391167
    KLXV 131321Z AUTO VRB05KT 3/4SM -SN VV017 M14/M17
    A2972 RMK AO2 P0000 T11391167
    KLXV 131333Z AUTO 31009KT 2SM -SN OVC017 M14/M17
    A2972 RMK AO2 P0000 T11391167

    ReplyDelete