Thursday, January 28, 2021

Aerodynamic Stall / Spin: Piper PA-24-250 Comanche, N6427P; fatal accident occurred July 26, 2018 at Palatka Municipal Airport (28J), Putnam County, Florida

Kimberly and David Niblett

Daniel Boggs, Investigator In Charge
National Transportation Safety Board
 

Aviation Accident Final Report - National Transportation Safety Board

The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Orlando, Florida
Piper Aircraft; Vero Beach, Florida
Lycoming Engines; Dallas, Texas

Investigation Docket - National Transportation Safety Board:


Location: Palatka, Florida 
Accident Number: ERA18FA200
Date & Time: July 25, 2018, 20:07 Local 
Registration: N6427P
Aircraft: Piper PA24 
Aircraft Damage: Destroyed
Defining Event: Aerodynamic stall/spin 
Injuries: 2 Fatal
Flight Conducted Under: Part 91: General aviation - Personal

Analysis

The accident flight was the private pilot's second solo flight in the accident airplane, which he had purchased and had first flown 13 days before the accident. A witness standing near the departure end of the runway stated that the pilot held the airplane's brakes while advancing the engine to full power, and he believed that the pilot was going to perform a short-field takeoff. As the airplane accelerated down the runway, the nosewheel lifted off then touched down again before the airplane rotated off the runway and began to climb. The witness further stated that he thought that the pilot had rotated the airplane "early," as the airplane appeared slow. The airplane's angle of climb continued to increase until, about 150 ft above ground level, the airplane entered an aerodynamic stall and spiraled to the ground.

Examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or abnormalities that would have precluded normal operation. Between the time of purchase and the accident flight, the pilot logged about 15 hours of flight instruction in the airplane; logbook remarks indicated that, during those flights, the pilot had received instruction in normal and crosswind takeoffs and landings. Autopsy and toxicology testing of the pilot identified no evidence of physiological impairment or incapacitation. The lack of mechanical anomalies, the witness statement, and the surveillance video footage are consistent with the pilot's exceedance of the airplane's critical angle of attack during the initial climb after takeoff, which resulted in an aerodynamic stall and a subsequent loss of control.

Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:
The pilot's exceedance of the airplane's critical angle of attack during the initial climb after takeoff, which resulted in an aerodynamic stall and a loss of control.

Findings

Personnel issues  Aircraft control - Pilot
Aircraft Angle of attack - Not attained/maintained

Factual Information

HISTORY OF FLIGHT

On July 26, 2018, about 2007 eastern daylight time, a Piper PA-24-250, N6427P, was destroyed when it impacted the ground during the initial climb after takeoff from Palatka Municipal Airport (28J), Palatka, Florida. The private pilot and passenger were fatally injured. The airplane was owned by the pilot who was operating it as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight.

A witness was standing in his hangar about 200 yards from the end of runway 17 when he heard the accident airplane beginning its takeoff. He noticed that the airplane's brakes were engaged while the engine was at full throttle and he believed that the pilot was going to perform a short-field takeoff. As the airplane rolled down the runway, it's nosewheel lifted off the ground then touched down again before the airplane became airborne. The witness thought that the pilot rotated the airplane "early," as the airplane appeared slow. He added that the airplane kept climbing "steeper and steeper" and that the pilot did not lower the nose to gain airspeed. When the airplane was about 150 ft above ground level, it
entered a stall and the left wing dropped; the airplane spiraled to the ground. The witness further stated that the engine was operating at full power during the entire flight.

An airport security video at 28J showed the airplane immediately after takeoff as it climbed to about 150 ft; the airplane's left wing dropped and the airplane spiraled to the ground, consistent with the witness' account.

PERSONNEL INFORMATION

The pilot held a private pilot certificate with ratings for airplane single-engine land and instrument airplane. He was operating under the provisions of the BasicMed; his most recent physical exam was completed on July 14, 2018. According to the pilot's logbook, he had a total of 704.4 hours of flight experience. The accident flight was the pilot's second solo flight in the airplane. The pilot purchased the airplane 13 days before the accident; since purchase, the pilot had logged 15.1 hours of flight instruction in the airplane. Logbook remarks indicated that, during those flights, the pilot had received instruction in normal and crosswind takeoffs and landings, approach and departure stalls, and simulated engine failures.

AIRCRAFT INFORMATION

The four seat, low-wing, tricycle gear airplane was manufactured in 1959. It was powered by a Lycoming O-540-A1C5, 250-horsepower engine equipped with a three-bladed McCauley propeller. The most recent annual inspection was completed on July 12, 2018. At the time of the accident, the airframe total time was 3,435.73 hours (13.73 hours since the annual inspection) and the engine had accrued 1,268 hours since major overhaul.

METEOROLOGICAL INFORMATION

At 2015, the recorded weather at 28J included wind from 180° at 5 knots, 10 statute miles visibility, temperature 27°C, dew point 26°C, and an altimeter setting of 29.98 inches of mercury.

WRECKAGE AND IMPACT INFORMATION

The wreckage was located about 60 ft to the left of and about halfway down the length of runway 17, which measured 3,510 ft long. The wreckage came to rest on a magnetic heading of 270°. The propeller was fractured from the engine and buried about 2 ft into the ground. The engine was displaced into the instrument panel and cockpit. The landing gear was extended, and the wing flaps were retracted. Both wings exhibited accordion-like crushing on the leading edges. Flight control cable continuity was established from the cockpit to all flight controls. The stabilator trim control was fragmented and the trim position could not be verified. Both pitch and trim servos rotated freely, and the clutch was not engaged. The fuselage was crushed, and the empennage was bent over top of the cabin. The vertical stabilizer, rudder, and elevator were not damaged.

The engine was removed from the airframe for further examination. The top spark plugs were removed, and a lighted borescope was used to look inside the cylinders. All valves and pistons showed normal wear. Thumb compression was confirmed on all cylinders. Drivetrain continuity was established through the engine and accessory case by rotating the propeller flange and observing the movement of the gears. Both magnetos were removed and turned by hand. All leads sparked to ground.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed on the pilot by the Office of the Medical Examiner, St. Augustine, Florida. The report listed the cause of death as multiple blunt force trauma.

Toxicology testing performed at the FAA Forensic Sciences Laboratory was negative for drugs and alcohol.

History of Flight

Initial climb Aerodynamic stall/spin (Defining event)
Uncontrolled descent Collision with terr/obj (non-CFIT)

Pilot Information

Certificate: Private
Age: 44,Male
Airplane Rating(s): Single-engine land
Seat Occupied: Left
Other Aircraft Rating(s): None 
Restraint Used: Unknown
Instrument Rating(s): Airplane 
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: Yes
Medical Certification: BasicMed 
Last FAA Medical Exam: July 14, 2018
Occupational Pilot: No 
Last Flight Review or Equivalent: July 16, 2018
Flight Time: 704.4 hours (Total, all aircraft), 15.1 hours (Total, this make and model), 660.5 hours (Pilot In Command, all aircraft), 38 hours (Last 90 days, all aircraft), 15.1 hours (Last 30 days, all aircraft)

Aircraft and Owner/Operator Information

Aircraft Make: Piper 
Registration: N6427P
Model/Series: PA24 250 
Aircraft Category: Airplane
Year of Manufacture: 1959
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: 24-1537
Landing Gear Type: Retractable - Tricycle 
Seats: 4
Date/Type of Last Inspection: July 12, 2018 Annual
Certified Max Gross Wt.: 2899 lbs
Time Since Last Inspection: 14 Hrs
Engines: 1 Reciprocating
Airframe Total Time: 3422 Hrs as of last inspection
Engine Manufacturer: Lycoming
ELT: C91 installed, not activated
Engine Model/Series: O-540 SERIES
Registered Owner: 
Rated Power: 250 Horsepower
Operator: On file 
Operating Certificate(s) Held: None

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual (VMC) 
Condition of Light: Dusk
Observation Facility, Elevation: 28J,47 ft msl 
Distance from Accident Site: 0 Nautical Miles
Observation Time: 20:15 Local
Direction from Accident Site: 0°
Lowest Cloud Condition: Clear 
Visibility 10 miles
Lowest Ceiling: None 
Visibility (RVR):
Wind Speed/Gusts: 5 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: 180° 
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 29.97 inches Hg
Temperature/Dew Point: 27°C / 26°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Palatka, FL (28J) 
Type of Flight Plan Filed: None
Destination: Palatka, FL (28J)
Type of Clearance: None
Departure Time: 20:07 Local 
Type of Airspace:

Airport Information

Airport: Palatka Muni - Lt Kay Larkin F 28J 
Runway Surface Type: Asphalt
Airport Elevation: 47 ft msl
Runway Surface Condition: Dry
Runway Used: 17 
IFR Approach: None
Runway Length/Width: 3510 ft / 75 ft 
VFR Approach/Landing: None

Wreckage and Impact Information

Crew Injuries: 1 Fatal 
Aircraft Damage: Destroyed
Passenger Injuries: 1 Fatal 
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 Fatal
Latitude, Longitude: 29.656389,-81.688613(est)










20 comments:

  1. if I figured correctly, his log thru 7/18 reflected 24 PA-24 landings over a 5 day period...

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  2. This happened in July, in Florida. Why is there snow on the ground in some of the photos...or is that some kind of fire-retardant sprayed by a fire/rescue squad?

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    1. Yes, it always snows in Florida, especially in July, being it's coldest month. C'mon, are you serious? Of course it's foam retardant.

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    2. It's aqueous film-forming foam.

      If the global warming crowd has its way, we’re going to be putting the well-being of our economy into the hands of people who have no real ability to control or predict the weather.

      Delete
    3. Like my father used to say: "There are no stupid questions - only stupid people that ask questions!".

      Thanks for the mid-morning chuckle! It's OK MoodyRiver - I forgive you!

      Delete
  3. It's rare to find an accident you just can't figure out, but this one makes absolutely no sense. A guy with 700 hours just up and stalls it on takeoff? Hard to comprehend.

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    1. I'm wondering if the seat unlatched and slid back. That has caused accidents in the past.

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    2. I agree...I have about the same amount of hours and most of those in a PA24-250. This accident is baffling to understand!

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    3. I agree...I have about the same amount of hours and most of those in a PA24-250. This accident is baffling to understand!

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    4. News story from 2018 includes Florida Highway Patrol statement saying the couple landed there to take on fuel. Notice that it has tip tanks. A fully tank-optioned Comanche is 90 gallons for main, aux and tip tanks loaded.

      The failed early takeoff rotation where he put the nose back down tells you that it was heavy and did not have the lift he expected at the airspeed he first rotated at.

      Makes sense that his personal limits for climb pitch and associated airspeed learned from training could cause a stall for full fuel load. Probably never trained with full fuel load during his 15 hours dual instruction, no need to have 90 gallons for lesson flights.

      https://www.jacksonville.com/news/20180808/ntsb-issues-preliminary-report-on-palatka-plane-crash-that-killed-husband-and-wife

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    5. ur "early takeoff rotation where he put the nose back down" is counter to "A witness standing near the departure end of the runway stated that the pilot held the airplane's brakes while advancing the engine to full power, and he believed that the pilot was going to perform a short-field takeoff. As the airplane accelerated down the runway, the nosewheel lifted off then touched down again before the airplane rotated off the runway and began to climb. The witness further stated that he thought that the pilot had rotated the airplane "early," as the airplane appeared slow. The airplane's angle of climb continued to increase until, about 150 ft above ground level, the airplane entered an aerodynamic stall and spiraled to the ground."

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    6. @Gbear- Unless that first nose wheel liftoff described by the witness was lofted by a bump on the runway, it was due to airframe rotation in response to pilot input. If the aircraft was trimmed for a three point liftoff without pilot input the main gear would not have stayed stuck to the runway.

      The 6:38 PM comment describes that first time the nose wheel came off as a failed early takeoff rotation. Witness stated that he thought that the pilot had rotated the airplane "early". Po-tay-toe, Po-tah-toe...

      There is a fuel receipt in the docket for 43 gallons. No way to know if the accident pilot was flying at a fully fueled weight since the NTSB report does not offer a total for estimated or reconstructed fuel on board.

      Price check at the time of this comment for self service 100LL at the accident airfield (28J, Lt. Kay Larkin Field) is $3.48. Thirty miles away at presumed home airfield KGNV, self service 100LL is $4.37.

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    7. But why would you climb at whatever pitch you're "used to" when the freaking airspeed is bleeding off towards a stall? It just makes no sense. Unless he was completely eyes outside, which doesn't make sense either. As my instructor taught me: "mind thy airspeed!"

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  4. Looking at the pictures, the left side seat appears to be at least 6 inches further back than the right seat. Any idea if the NTSB investigated the seat rails and documented the latch position after the accident?

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    Replies
    1. Preservation of as found seat position is not guaranteed due to emergency crew activity during victim extraction, but broken and/or worn parts are easy to evaluate.

      Examination of the seat rails for wear and condition of the latch mechanism is probably standard activity by NTSB for all high angle takeoff stalls, given the well known examples from worn Cessna rails.

      Examination would still be done by NTSB even if no worn Piper latch or rail parts ever failed that way.

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    2. I am surprised they didn't mention it in the report at all, that's what I'm getting at.

      I thought about emergency crews, but considering the airplane was in a near vertical attitude the way it is crashed, it didn't seem likely that they would slid the seat straight up. It is possible though.

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    3. If NTSB review determined that a Piper OEM seat stop P/N 18842-000 was not installed on the seat rails or conditions existed that impaired seat latch function, the report would have mentioned those findings.

      It is possible for a seat unlatching event to occur that does not leave observable indications, but with Piper seat rails, roller housings and latch pins not being the subject of Airworthiness Directives like Cessna aircraft have been, the NTSB would not be expected to mention that nothing discrepant was found in this case.

      It is a fair bet that considerable review effort and discussion took place trying to decide whether that portion of video captured on the 28J camera represented a too aggressive max climb or another seat slide back crash. Replaying, even at 1/4 speed, will leave most people unable to decide.

      Those who worked on the investigation do not deserve to be scorned on a video platform by persons unaware of the full effort that was made.

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    4. I'm not trying to scorn the NTSB, I am sorry you feel that way. Thanks.

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    5. The comment about scorn was not directed at you. A person on the well known video platform has posted harsh criticism of the NTSB about this accident. Your question was well considered, not scorn. Best Regards.

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  5. I am surprised they didn't mention it in the report at all, that's what I'm getting at.

    I thought about emergency crews, but considering the airplane was in a near vertical attitude the way it is crashed, it didn't seem likely that they would slid the seat straight up. It is possible though.

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