Boynton Beach, FL, USA
N5757L
American Aviation AA 1
Radar data indicated that, after departure, the pilot climbed the airplane to about 1,700 feet mean sea level (msl) in a gradual right turn. The airplane then began to descend, and its groundspeed decreased until radar contact was lost. The last radar return indicated an altitude of 550 feet msl and a ground speed of about 43 knots near the accident site. A witness reported that the airplane's wings appeared to "waggle" up and down, and the airplane suddenly appeared to go inverted. The airplane’s nose pointed at the ground, and the airplane began to corkscrew rapidly while losing altitude and disappeared behind a tree line. Another witness heard what she thought sounded like a boat having engine trouble, then heard a loud thump. No evidence of any preimpact failures or malfunctions of the airplane or engine were discovered that would have prevented normal operation. The propeller blades did not exhibit any rotational signatures, consistent with the engine not producing power at the time of impact. There was no evidence of residual fuel inside either of the fuel tanks, the fuel selector valve, or the mechanical fuel pump, and the carburetor float bowl contained only about 2 drops of fuel. There was no odor of fuel on-scene, and no observed fuel blight near the wreckage. The airplane’s most recent documented annual inspection was about 4 years before the accident. An acquaintance of the accident pilot reported that the pilot, who was a mechanic, had been working on the airplane for about 1.5 years. The acquaintance communicated with the pilot 3 days before the accident, during which the pilot reported that he flew the airplane and that the airspeed indicator seemed to be indicating “high” and that the stall warning horn activated below 85 mph. The pilot reported that he “didn’t feel like [the airplane] was stalling but it did feel slow.” Review of maintenance records did not reveal any entries pertaining to the pitot-static system. Based on the available evidence, it is likely that the pilot did not verify the fuel quantity before he departed on the accident flight, which resulted in a total loss of engine power due to fuel exhaustion. It is also likely that, following the loss of engine power, the pilot failed to maintain airspeed and exceeded the airplane’s critical angle of attack, which resulted in an aerodynamic stall and loss of control. The extent to which the reported airspeed indicator/stall warning anomaly may have contributed to the accident could not be determined based on the available information.
HISTORY OF FLIGHTOn March 6, 2020, about 1316 eastern standard time, an American Aviation AA-1, N5757L, was substantially damaged when it was involved in an accident in Boynton Beach, Florida. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 maintenance test flight. Radar track data provided by the Federal Aviation Administration (FAA) indicated that, after departure, the airplane first appeared on radar at 1313:52, when it was about 1.43 nautical miles (nm) southeast of the airport at an altitude of 1,350 ft mean sea level (msl). At that time, the airplane was heading east-southeast in a climbing right turn, with a ground speed of about 84 knots. The airplane continued a climbing right turn to about 1,700 ft msl, and then turned momentarily to the west-northwest before turning left to the southwest, and then west-southwest. The airplane then began to descend, with ground speed also decreasing until the track was lost at 1315:41, at an altitude of 550 ft msl, with a ground peed of about 43 knots, close to the accident site. According to a witness who saw the airplane moments before the accident, the airplane's wings appeared to "waggle" up and down, and the airplane suddenly appeared to go inverted. The nose of the airplane then pointed at the ground, and the airplane began to corkscrew rapidly while losing altitude and disappeared behind a tree line. Another witness, who resided near the accident site and had the back windows of her home open, heard what she thought sounded like a boat having engine trouble, then heard a loud thump. AIRCRAFT INFORMATIONThe airplane was a single-engine, low wing, tricycle landing gear equipped, two place, monoplane of all-metal bonded construction. It was powered by a Lycoming 108-horsepower, 4-cylinder, horizontally opposed, air cooled engine, driving a fixed pitch, McCauley 2-bladed metal propeller. According to FAA airworthiness and airplane maintenance records, the airplane was manufactured in 1969. Its most recent annual inspection was completed on January 6, 2016 (about 4 years before the accident). At the time of the inspection, the airplane had accrued about 1,961.9 total hours of operation. The airplane's registration expired on September 30, 2019, and the airplane was deregistered by the FAA on January 6, 2020. AIRPORT INFORMATIONThe airplane was a single-engine, low wing, tricycle landing gear equipped, two place, monoplane of all-metal bonded construction. It was powered by a Lycoming 108-horsepower, 4-cylinder, horizontally opposed, air cooled engine, driving a fixed pitch, McCauley 2-bladed metal propeller. According to FAA airworthiness and airplane maintenance records, the airplane was manufactured in 1969. Its most recent annual inspection was completed on January 6, 2016 (about 4 years before the accident). At the time of the inspection, the airplane had accrued about 1,961.9 total hours of operation. The airplane's registration expired on September 30, 2019, and the airplane was deregistered by the FAA on January 6, 2020. WRECKAGE AND IMPACT INFORMATIONExamination of the accident site revealed that the airplane impacted a 40-inch diameter, 18-foot-high palm tree, severing it about 5 feet above ground level. The airplane came to rest against a fence in a 22° nose-down attitude, on a 33° magnetic heading, about 30 feet from the back wall of a residence. A debris path composed mostly of debris from the palm tree, light objects from the interior of the airplane, and Plexiglas from the windshield and sliding cockpit canopy continued from the main wreckage on a magnetic heading of 44° for about 71 feet, until it met the western edge of the Lake Ida Canal, which paralleled the backyards of the residences surrounding the accident site. Examination of the wreckage revealed no evidence of any preimpact fire or explosion. The left wing was partially separated from the fuselage. The left wing appeared largely intact, with the wing flaps and ailerons remaining attached. The wing was curled forward with the leading-edge showing evidence of impact damage with roughly five separate wrinkles in the skin of the leading edge, The pitot tube was blocked with soil and debris from the accident site and was separated from its mounting position. The right wing was partially separated from the fuselage mounting points and remained attached to the fuselage by the flap and aileron control tubes. The right wing was broken nearly in half at mid-span. Both the aileron and wing flap assemblies were damaged and bent rearward with the arc of the bend matching the circumference of the broken palm tree, which displayed paint transfer and debris from the wing. Evidence of tree material was also present inside the structure of the right wing. Flight control continuity was established from the cockpit to each respective flight control surface. Examination of the cockpit revealed that the throttle control was out about 2 inches, bent to the left, and broken off. The mixture control was full forward, and the engine primer was in and locked. The fuel selector handle was bent to the left toward the left tank position. The tachometer indicated 2,031.7 total hours of operation. No emergency locator transmitter (ELT) was installed. The left wing fuel tank displayed significant damage and was ruptured at the inboard end near the fuselage. The right wing fuel tank was ruptured at the inboard end and middle section. There was no evidence of residual fuel inside either of the fuel tanks, there was no odor of fuel, and no observed fuel blight (browning of vegetation). Disassembly of the fuel selector valve revealed that it was devoid of fuel, and it was not in the detent for either the left or right fuel tanks. Disassembly of the engine-driven fuel pump revealed that it was devoid of fuel, and disassembly of the carburetor reveled that a trace amount (about 2 drops) of fuel were present inside the carburetor float bowl. One blade of the two-bladed propeller was bent back about 20°, and the other blade was relatively straight with a slight wave about mid-span. Neither propeller blade displayed leading edge gouging, chordwise scratching, or S-bending. Examination of the engine revealed that there was oil in the sump, galleries, and rocker boxes. The left magneto produced spark at all four towers, and the right magneto, though impact damaged, displayed no evidence of any preimpact failure or malfunction. Thumb compression and suction was present on all four cylinders, and continuity was confirmed from the crankshaft to the accessory gears and to the valvetrain. ADDITIONAL INFORMATIONAn acquaintance of the pilot stated that the airplane had not flown for 2 to 3 years, and the pilot had been working on getting the airplane airworthy for about 1.5 years before the accident. He saw the pilot working on the airplane on the morning of the accident. The acquaintance also stated that the pilot bought about 13.5 gallons of fuel on March 3, 2020. The acquaintance reported that he had communicated with the pilot via text message 3 days before the accident, during which the pilot stated that he had flown the airplane, that the airspeed indicator was “high” and that the “stall warning [was] going off all the time” below 85 mph. The pilot also stated, “… it didn’t feel like it was stalling but it did feel slow.” MEDICAL AND PATHOLOGICAL INFORMATIONAn autopsy performed on the pilot by the Office of the District Medical Examiner, Palm Beach County, Florida, reported the cause of death as multiple blunt force injuries. Toxicological testing performed at the FAA Forensic Sciences Laboratory was negative for carboxyhemoglobin, drugs, or alcohol.
The pilot's inadequate preflight fuel planning, which resulted in a total loss of engine power due to fuel exhaustion, and his exceedance of the airplane’s critical angle of attack following the loss of engine power, which resulted in an aerodynamic stall and loss of control.
Source: NTSB Aviation Accident Database
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