NYC02LA198

NTSB accident investigation · North American AT-6D · Circleville, OH · September 29, 2002

Accident · FatalLimited investigationFinal report
Date
September 29, 2002, 14:30 local (18:30 UTC)
Place
Circleville, OH
Injuries
1 fatal
Damage
Destroyed
Phase of flight
Maneuvering
Aircraft
N29930North American AT-6D
Weather
Visual (VMC) · Day
Status
Completed · report May 30, 2003
Report
Approved by Office Director
Parties
FAA/FSDO
FAA report
20020929038209A
Case key
55792

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

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Probable cause

The pilot's failure to maintain adequate airspeed during the course reversal, which resulted in an inadvertent stall/spin.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of control - in flightManeuvering - turn to reverse direction
Airspeed - not maintainedPilot in commandCause
Stall - inadvertentPilot in command
In flight collision with terrain/waterDescent - uncontrolled
Terrain condition - ground

Analysis

During an airshow, the accident airplane flew by as the lead of a four-ship, single-file pass. When it reached the end of the runway, it began a climbing right turn, with an intended course reversal. Near the completion of the turn, the airplane suddenly rolled further right, the nose pitched down, and the airplane subsequently impacted the ground almost vertically. There were no mechanical anomalies noted.

Factual narrative

On September 29, 2002, about 1430 eastern daylight time, a North American AT-6D, N29930, was destroyed when it impacted the ground while maneuvering at Pickaway County Memorial Airport (CYO), Circleville, Ohio. The certificated commercial pilot was fatally injured. Visual meteorological conditions prevailed at the time. No flight plan had been filed for the local air show flight, which was conducted under 14 CFR Part 91.

According to a Federal Aviation Administration (FAA) inspector, witnesses reported that the airplane had previously made a pass as the lead of a four-ship echelon formation. The formation broke up, and the airplane then led the other three airplanes in a low level, single file pass along runway 01. When the airplane reached the end of the runway, it began a climbing turn, which was "noticeably slow compared to the other airplanes." The airplane climbed, stalled, and pitched downwards about 75 degrees nose-low before impacting a fallow cornfield. None of the witnesses heard any abnormal engine noises before or during the accident.

The pilot of the second airplane stated that at the time of the accident, after the fly-by, the intent was to turn slightly to the left, to a heading of "north," then pitch up no more than 20 degrees, bank right to a southerly heading and descend back to the original altitude. When the accident airplane had nearly completed the turn at an estimated 800 feet above the ground, he saw it roll further right to an inverted position. It then descended to the ground nearly vertically, with the left wing "slightly low."

The pilot of the second airplane felt that the accident airplane entered an accelerated stall.

The pilot of the third airplane stated that his view was partially obscured by smoke emitted from the accident airplane and the number two airplane. His attention was drawn to the accident airplane "by the lack of movement of its shadow across the ground." Shortly thereafter, the shadow and the accident airplane "merged."

The pilot of the fourth airplane reported that he did not witness the accident. His first indication of a problem was when he heard a "knock it off" call from one of the other remaining airplanes.

The fourth pilot also reported that the accident flight was the second flight of the day, and was planned to be identical to the first flight. In addition, the pilots had physically walked through the maneuver sequence on the ramp. The planned course reversal where the accident occurred was not planned as a "high-g" turn, but more closely resembled a "dog-bone" maneuver. There was supposed to be an initial slight left turn with a shallow, 500-fpm climb, then a right turn to reverse course followed by a descent at the same rate.

A witness on the ground, who controlled air and ground traffic for the air show, stated that the accident airplane passed by him, then turned north of a farm house to come back for another pass. The accident airplane made a steep turn of "60 degrees or more," then "leveled out" and was heading southeast when it "[went] up and left wing over (in a stall) configuration." The airplane then descended, "almost vertical into the ground." The left wing struck the ground first, and the airplane exploded.

Another witness on the ground stated that after the airplane made a low level pass, it "started to gain altitude and make a right turn." It then went "nose down" and straight into the ground.

The pilot of the fourth airplane described the stall characteristics of the T-6 as "honest." During a full stall, the airplane would break right four out of five times, and directional control could be "easily maintained with rudder input throughout the stall maneuver." After the accident, he practiced multiple stalls and recoveries, and even held continuous back pressure on the control stick. Directional control was maintained, and recovery was made by releasing the back pressure.

According to the FAA inspector, all flight control surfaces were accounted for at the accident scene, and there were no ground scars other than those directly below the wreckage. The cockpit and much of the wing area were consumed by fire. Both of the airplane's wings had leading edge crushing, aft to the spars, about 90 degrees perpendicular to the chord line. The propeller blades had leading edge nicks, and one blade tip was curled back "like a ram's horn."

The pilot held a commercial certificate with ratings for airplane single engine land and instrument airplane. The pilot's logbooks were not recovered.

The pilot's latest FAA second class medical certificate was issued on August 7, 2002. At the time, he reported 2,400 hours of total flight time.

According to the local coroner's office, no autopsy was performed due to the condition of the remains. Toxicological specimens were provided to the FAA Toxicology and Accident Research Laboratory, Oklahoma City, Oklahoma; however, "no suitable specimens in sufficient amounts were submitted for analysis."

Weather, recorded at an airport about 20 nautical miles to the north, about the time of the accident, included clear skies and calm winds.

Aircraft

Registration
N29930
Reported as
North American AT-6D
Category
Airplane
Serial number
91088
Airframe hours
6,824
Engine
Pratt & Whitney R-1340, 600 horsepower, reciprocating
Damage
Destroyed
Fire
On-Ground
Flight
Air race/show · Part 91
Registered owner
Robert C. Backman
Airworthiness certificate
Standard, Normal
Last inspection
Annual · April 4, 2002
Departed
CYO · Circleville, OH
Airport
CYO · Pickaway County Memorial, runway 01, 4,351 × 75 ft, asphalt

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
54
Injuries
Fatal
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 2, Valid Medical--w/ waivers/lim
Seat
Front
Toxicology
Performed
Flight hours
2,400 total · 1,000 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
77 °F, dew point 63 °F
Altimeter
30.17 inHg
Observed at
LCK, 20 nm away

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.