History of Flight
On May 22, 2008, at 1158 eastern daylight time, a Grumman American AA-1C, N9555U, impacted a parked trailer shortly after takeoff from Northeast Philadelphia Airport (PNE), Philadelphia, Pennsylvania. The airplane was substantially damaged. The certificated flight instructor (CFI) and student pilot were killed. The airplane was operated by a flight school and based at PNE. Visual meteorological conditions prevailed, and no flight plan was filed for the local instructional flight conducted under 14 CFR Part 91.
According to air traffic controllers and recorded communications, the accident airplane was in the left traffic pattern for runway 33, practicing touch-and-go landings. Two other aircraft were in the right traffic pattern. A helicopter was at the intersection of taxiways Gulf and Juliet, instructed to hold until the accident airplane landed. As the accident airplane touched down, the controller cleared the helicopter for takeoff, stating the accident airplane would be on a left downwind departure. As the airplane climbed after landing, the controller instructed, "five five uniform make right traffic." The accident pilots did not acknowledge. Controllers observed the airplane bank hard right at an altitude of 200 feet, then continue in a descending right bank until impact.
A helicopter pilot reported that the airplane departed and climbed slowly. At about 200 feet, it initiated a 10-20 degree right bank that did not appear coordinated. The bank increased to 30 degrees, then the wings fluttered and the airplane stalled. The right wing and nose dropped to an 80-90 degree bank, and he lost sight behind parked trailers. He noted a lot of wind, from 290-300 degrees at 15-20 knots. Another witness saw the airplane take off, then go vertical at 200 feet and kick hard right, resembling a takeoff stall with a right turn and high angle of attack. The airplane banked right, came down on its side behind trailers, and smoke appeared about 5 seconds later.
Personnel Information
The CFI, age 28, held a flight instructor certificate with single-engine land and instrument ratings, and a commercial pilot certificate with single- and multi-engine land and instrument ratings. His most recent first-class medical was issued February 21, 2008, reporting 1,500 total flight hours. An insurance form from January 9, 2008 indicated 1,600 hours as an instructor and 800 hours in the accident make and model.
The student pilot's most recent second-class medical was issued May 9, 2007, reporting 20 total hours. Flight school records as of May 10, 2008 showed approximately 87 total hours, all in the accident make and model. The accident flight was to be his last instructional flight before a private pilot check ride.
Aircraft Information
The airplane was manufactured in 1977 and equipped with a Lycoming O-235 engine. Its most recent 100-hour inspection was performed March 28, 2008, with no anomalies noted. The airplane had flown approximately 96 hours since the inspection.
Meteorological Information
Weather reported at PNE at 1154 included wind from 310 degrees at 8 knots, 10 miles visibility, light rain, scattered clouds at 3,600 feet, and broken clouds at 4,300 feet. At 1054, winds were recorded from 270 degrees at 17 knots, gusting to 25 knots.
Airport Information
Northeast Philadelphia Airport has two crossing runways oriented 6/24 and 15/33.
Wreckage and Impact Information
The airplane struck a parked trailer at a warehouse off the departure end of runway 33, adjacent to the airport perimeter fence. Green paint transfer matching the airplane's color was on the side corner of the trailer. An adjacent trailer about two feet away was undisturbed. About 14 feet from the trailer, an impact mark with red paint transfer consistent with the propeller spinner was on the pavement. The wreckage path continued on an approximate 170-degree heading to the main wreckage. Remnants of the right wingtip light and Plexiglas canopy sections were along the path.
The airplane came to rest under a parked trailer docked to a warehouse loading bay. It remained relatively intact but was almost completely consumed by a post-impact fire. All flight controls remained attached, and continuity was confirmed from controls to cockpit. The engine remained attached to the firewall; the propeller was separated and found about 20 feet away. One propeller blade had a slight S-bend; the other was curled aft with severe chordwise scratching. The spinner was severely dented, with the curled blade inside.
Examination of the engine revealed it could not initially be rotated due to impact damage to the number 1 cylinder. That cylinder was removed; valve train continuity and thumb compression were confirmed on the remaining three cylinders. Magnetos could not be tested due to fire damage. Spark plugs showed the bottom number 1 and number 3 plugs were oil soaked; the others appeared normal to worn-out normal per a Champion spark plug chart.
Medical and Pathological Information
Autopsies performed by the City of Philadelphia Medical Examiner's Office listed the student pilot's cause of death as cerebral injury and smoke and soot inhalation, and the CFI's cause of death as blunt trauma and smoke and soot inhalation. Toxicological testing by the FAA Bioaeronautical Research Laboratory detected 22% carbon monoxide and 1.2 ug/ml cyanide in the student pilot's blood, and 17% carbon monoxide and 0.48 ug/ml cyanide in the CFI's blood.
Tests and Research
A security camera at the warehouse captured five frames over a five-second period. The first frame showed the airplane in a 90-degree right bank on an approximate heading of 330 degrees. The second frame showed it descending in the same bank. The third frame indicated the airplane continued its descent and bank, now oriented nose-down on a heading of about 150 degrees, striking a parked trailer with its right wing. The fourth frame showed the airplane on the pavement between rows of trailers in a level attitude. The fifth frame showed it under another row of trailers docked to the warehouse.
Additional Information
The FAA Airplane Flying Handbook and Advisory Circulars provide information on accelerated stalls and load factors relative to bank angles, but these are not presented as causal to this accident.