NTSB Factual Report

HISTORY OF FLIGHT

On March 29, 2015, about 1335 eastern daylight time, a privately owned and operated Piper PA-28-140, N6842W, crashed shortly after takeoff from Brandywine Airport (OQN), West Chester, Pennsylvania. The airplane was destroyed by impact and a postcrash fire, and the flight instructor and private pilot were fatally injured. Visual meteorological conditions prevailed at the time and no flight plan was filed for the local personal flight that was conducted under the provisions of 14 Code of Federal Regulations (CFR) Part 91. The flight was originating at the time of the accident.

The purpose of the flight was a flight review for the airplane owner, who had reportedly not flown since 2011.

According to witnesses, two engine run-ups were performed before the accident flight. During the first run-up, when one of the magnetos was checked, the engine sounded rough and remained at a higher rpm for a period of time, before power was reduced to idle. During the second magneto check, the engine sounded better than the previous check. The airplane then taxied onto the runway and began a takeoff roll from runway 27, which was aborted for unknown reasons. One witness stated that he did not hear any abnormal engine sounds associated with the aborted takeoff. The airplane then returned to the approach end of runway 27, for a second takeoff attempt.

A witness adjacent to the approach end of the runway stated he did not hear an engine run-up, and reported he heard four "pop" sounds followed by a loud "pop" sound, when the airplane was still on the ground, about halfway down the runway. The "pop" sounds quit and the airplane rotated about abeam the windsock, or about 1,070 feet down the runway. After rotation as soon as the airplane began to climb, the wings wobbled, the engine "sputtered badly…", quit, and then resumed normal operation. The sputtering lasted 3 to 4 seconds and during that time the airplane travelled the length of two runway centerline markings. During that time the airplane levelled off; however, the sputtering was enough for one witness to exclaim aloud three times, "put it down." Another witness indicated that if he had a VHF radio with him he would have broadcast "abort" when the sputtering occurred while the airplane was just above the runway.

The flight continued and a witness who was at the approach end of runway 27 reported an estimated 5 seconds after he heard the first pop sound, that the engine popped eight times over a period of 1 to 2 seconds. At that time the airplane appeared to be in a wings level attitude between 10 to 100 feet above ground level (agl), and about 3/4 down the runway. As the airplane neared the end of the runway, "…the engine sputtered again and restarted." The flight continued and was over or near U.S. Route 202 (Route 202), west of the departure end of the runway, in a climb about 200 feet agl when the engine "sputtered badly again." The airplane then banked to the left, flew above Route 202 in a southerly direction, and while in a nose-up attitude, banked left again to a "wings vertical" attitude, before it pitched nose-down and entered an incipient spin. The airplane disappeared from view of the witnesses and about 20 seconds later, black smoke was noted which then changed to white in color. Witnesses further reported that there was no smoke training the airplane or any other visual evidence of an in-flight fire prior to the accident.

PERSONNEL INFORMATION

The flight instructor, age 67, held an airline transport pilot certificate with airplane single-engine land, and airplane multiengine land ratings; and a flight instructor certificate with airplane single-engine, airplane multiengine, and instrument airplane ratings. He was issued a second-class medical certificate on December 16, 2014, with a limitation, "Must wear corrective lenses and possess glasses for near and interim vision." At that time, he listed a total flight time of 12,093 hours. His last flight review in accordance with 14 CFR Part 61.56 occurred on June 6, 2014; it was performed in a Beech 23.

The pilot/owner, age 64, held a private pilot certificate with an airplane single-engine land rating. He also held a third-class medical certificate issued December 22, 2014, with a limitation, "must have available glasses for near vision." At that time, he listed a total flight time of 224 hours. An "Aircraft Logbook" that contained entries associated with flights recorded his last flight as July 6, 2011. On the pilot's insurance application dated September 3, 2011, he indicated his total time was 228 hours, which included 114 hours in make and model, and 7 hours flown in the last 12 months.

AIRCRAFT INFORMATION

The PA-28-140 airplane was manufactured in 1965 by Piper Aircraft, and was designated serial number 28-20985. It was powered by a 150 horsepower Lycoming O-320-E2A engine, that was equipped with a two-blade, metal, fixed pitch Sensenich M74DM-0-58 propeller.

The airplane's previous flight was about 4.5 months earlier when it was flown from Philadelphia, Pennsylvania, to OQN, for completion of an annual inspection. The pilot who flew the airplane was also the mechanic who performed the latest annual inspection, and he indicated there were no issues with the engine during the flight.

The annual inspection was signed-off as being completed on December 11, 2014. Maintenance records indicated that the airplane total time at that time was 2,749.2 hours. The airplane was not test flown by the mechanic in conjunction with completion of the annual inspection; however, the engine was operated twice by him. One time to full-rated rpm during an extensive ground run-up with no discrepancies reported. The mechanic indicated that following the second engine run, his typical procedure was to place the fuel selector valve in the off position, which he likely did. Documents associated with the annual inspection indicated in part, that a leaking gascolator was repaired.

A review of OQN fueling records revealed that 29.4 gallons of fuel were added to the airplane on February 3, 2015. According to the airport manager, there were no fuel related issues reported by the pilots or owners of any refueled aircraft.

METEOROLOGICAL INFORMATION

A weather observation taken at Chester County GO Carlson Airport (MQS), Coatesville, Pennsylvania, which was located about 13 nautical miles west of the accident site, about the time of the accident, reported the wind was from 320 degrees at 10 knots, with gusts to 15 knots, the visibility was 10 statute miles in clear skies. The temperature and dew point were 2 and minus 13 degrees Celsius, respectively, and the altimeter was 30.29 inches of mercury.

AIRPORT INFORMATION

The Brandywine Airport was equipped with a single asphalt runway designated 09/27, which was 3,347 feet-long, by 50 feet-wide. The airport had a common traffic advisory frequency that was not recorded and was not monitored at the time of the accident.

The airport manager reported seeing a stain on the ramp the day of the accident, in the area where the airplane was parked. NTSB review of provided photographs revealed that the stain was mostly to the left of the line for the nose landing gear and aft of the nose landing gear chock. The stain did not extend beyond the resting position of the nose chock.

WRECKAGE AND IMPACT INFORMATION

The airplane crashed in the backyard of a residence. Property damage consisted of damage to two small trees and some ground debris. The wreckage was located about 1/2 nautical mile southwest from the departure end of runway 27. All components necessary to sustain flight were accounted for at the accident site. A postcrash fire consumed a majority of the airplane.

Examination of the airplane revealed the cockpit, cabin, and empennage were nearly completely consumed by postcrash fire. The nose gear displayed substantial fire and impact damage and was folded under the engine. Both front seats were loose from the structure and all combustible material had been consumed. Two fastened lap belt buckles were recovered with attach points for shoulder belts, but no belts were attached. The rear seat frame was loose from the structure and all combustible material was consumed. Flight control continuity was confirmed for roll, pitch, and yaw.

Examination of the firewall revealed the auxiliary fuel pump was heat damaged which precluded operational testing; the fuel lines from it were damaged and exposed to the environment. The bottom of the fuel pump, which was safety wired, was removed and the filter was found in-place but fractured. Components of the gascolator consisting of the bracket, outlet tube assembly, bail wire and nut, the drain valve and fitting were identified in the wreckage. The drain valve exhibited evidence of heat damage associated with the postcrash fire, and some impact damage. The gascolator drain valve was retained and forwarded to the NTSB Materials Laboratory, Washington, D.C. for further examination.

The left wing was oriented on a magnetic heading of 352 degrees, and was nearly completely consumed by the postcrash fire. The left wing fuel tank finger screen was clean. The vented fuel cap was in place, and secure; some remains of the seal were observed. The wingtip was attached. Remaining structure from both the aileron and flap were evident. The aileron bellcrank was in-place but loose from the remaining structure. The left main landing gear was evident but displayed substantial fire damage, and the tire was consumed.

Examination of the right wing revealed it was fractured at the wing root, and also at the outboard side of the fuel tank. The right wing fuel tank was mostly consumed by the postcrash fire. The fuel tank finger screen was partially covered by debris from the surrounding fire damage, but was otherwise clean. The vented fuel cap was in place, and secure; the seal was melted. The wingtip was attached, and the lens was in-place. Remaining structure from the aileron and flap were evident. The aileron bellcrank was in-place but loose from the remaining structure. The right main landing gear was evident but displayed substantial fire damage, and the tire was consumed.

Examination of the cockpit revealed that the flap selector was separated from its attach point, and was positioned between the fully retracted position and the first notch. The flap torque tube was also separated from its attach point. Examination of the left flap hinge at the wing root revealed the flaps were retracted. Continuity of the control cable from the flap selector to the flap torque tube was noted. Examination of the rudder torque tube revealed one cable was connected to the torque tube and one cable was attached to the torque tube attach point, but the attach point was fractured at the weld. The fuel selector was located loose in the wreckage, and found to have sustained fire damage. Examination of the fuel selector valve revealed it was between positions. Debris was noted in the inlet from the right tank; however, two of the three lines were fractured and exposed to the environment. The tachometer was located and indicated zero; the recording time was not determined and no "needle slap mark" was noted.

Examination of the empennage revealed the vertical stabilizer was in place and mostly consumed. The rudder was in place and secure at all hinge points; the stop bolts were in place and secure. The rudder control cables were secure to the bellcrank and continuous to the rudder bar fittings. The right side fitting was secure to the rudder pedals and the left side fitting was broken from the pedal assembly at the weld. The horizontal stabilator was in place and displayed impact and fire damage. The stop bolts were in place and secure. The balance tube was in place and secure. Both the upper and lower stabilator control cables were secure to the tube, continuous and secure to the control wheel T-bar. The remaining portion of the pitch trim tab was in place. The pitch trim drum was separated by fire from the structure, but the trim cables were in place and securely wrapped. The inner trim drum shaft was in place and displayed 10 threads of upper extension, which was consistent with a setting of approximately 6 degrees nose up trim, of the available 12 degrees.

The engine was partially impact separated from the airframe, but the firewall, nose gear, and rudder bar remained connected to the engine. All components sustained substantial impact and thermal damage from the postimpact fire. The propeller was separated from the engine but found in close proximity to the main wreckage. All fluid carrying lines were fire destroyed.

Further examination of the engine revealed the engine-driven fuel pump remained secured on its respective mount; however, thermal and impact damage precluded operational testing. Thumb suction and compression was verified in cylinder Nos. 1, 2, and 3; however, initially no thumb suction or compression was noted in the No. 4 cylinder, which exhibited extensive heat damage. The exhaust valve of the No. 4 cylinder was "staked," and then thumb suction and compression was noted. All cylinders were examined using a lighted borescope. It was noted that the tops of all of the pistons were absent of combustion deposits, and there was no evidence of detonation to any of the pistons. The oil measuring stick and housing was impact and fire destroyed. An unmeasured amount of oil was observed in the engine. Examination of the propeller flange of the crankshaft revealed it was broken in half and the remaining portion of the flange remained attached to the propeller hub. Examination of the exhaust system revealed carbon deposits inside the exhaust tubes consistent with normal combustion, while examination of the heat muff revealed no breach or carbon deposits. The carburetor was impact separated from the engine at the throttle plate, but remained connected by the mixture control cable. The throttle cable remained attached to the throttle lever. Further examination of the carburetor revealed the data plate was stamped with "MF" and "V", and a one-piece venturi was in-place. The bowl was secured by four screws, which were safety wired. The inlet fitting was fractured. The mixture was in the idle cut-off position based on the mixture control valve silhouette with the mixture housing. Impact and fire damage precluded operational testing of the carburetor. Both magnetos remained securely attached to their respective mounts; but both magnetos and the ignition harness exhibited extensive fire damage that precluded operational testing. Examination of the spark plugs revealed all exhibited normal wear. The Nos. 1 bottom and 2 top spark plugs were oil soaked, and both plugs of the No. 4 cylinder exhibited dark coloration.

Examination of the propeller revealed the spinner exhibited straight-line compression folds consistent with minimal rotation at impact. One blade exhibited a smooth radius aft bend of about 20 degrees beginning about 22.5 inches from the blade tip. The leading edge from about 12 inches from the tip to the hub exhibited light scratches on the leading edge. The blade exhibited some chordwise scratches on the blade face. The second blade exhibited a smooth radius forward bend, chordwise and spanwise scratches on the blade face. Heavy gouges were noted on the leading edge of the blade. The trailing edge of the blade exhibited a compression wrinkle on the blade face about 13.5 inches from the hub.

MEDICAL AND PATHOLOGICAL INFORMATION

Postmortem examinations of the occupants were performed by Forensic Pathology Consultants, Inc., Philadelphia, Pennsylvania. The cause of death for both was listed as multiple injuries.

Forensic toxicology was performed on specimens of the occupants by the Federal Aviation Administration Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology reports for both indicated the results were negative for carbon monoxide, volatiles, and tested drugs; testing for cyanide was not performed.

TESTS AND RESEARCH

According to the NTSB Materials Laboratory Factual Report, examination of the gascolator drain valve revealed that the valve stem exhibited impact damage and the locks were bent. Scrapes and d

NTSB Probable Cause

The failure of the flight instructor and the pilot to abort the takeoff after the airplane experienced a partial loss of engine power with adequate runway remaining, and their subsequent failure to maintain adequate airspeed, which led to the airplane exceeding its critical angle-of-attack and experiencing an aerodynamic stall. Contributing to the accident was an intermittent loss of engine power for reasons that could not be determined during postaccident examination of the wreckage due to extensive postcrash fire damage.