History of Flight
On November 18, 2012, at about 1320 central standard time, a Grumman American Aviation Corporation AA-1B airplane, registration N6273L, impacted terrain near Burlington, Wisconsin. The private pilot and passenger sustained fatal injuries, and the airplane was substantially damaged. The flight was operated under 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The local flight originated from Burlington Municipal Airport (KBUU) at an undetermined time.
An eyewitness, who was flying in the traffic pattern for runway 19, observed the accident airplane approaching from the southwest, consistent with an attempt to land on runway 11. Shortly thereafter, another pilot announced on the common traffic advisory frequency (CTAF) that they were departing on runway 29. The witness located both airplanes and did not perceive an imminent collision hazard. The accident airplane then appeared to enter a steep descent with a slight left turn, followed by a tight right turn that developed into a spin, rapidly descending toward the terrain.
The pilot of the departing airplane reported being unaware of the accident airplane’s location during departure and did not see it or hear any radio calls.
Personnel Information
The pilot, age 50, held a private pilot certificate with a single-engine land rating. He received a Special Restriction third class medical certificate on July 12, 2012, due to treatment for psoriatic arthritis, with the restriction that it was not valid after July 31, 2013. On his medical application, he reported 290 total flight hours, with 7 hours in the preceding six months.
The pilot’s logbook, recovered from the wreckage, showed the most recent entry on May 30, 2012, recording 1.2 hours and four landings. There was no record of flights in the preceding five months. Logbook entries indicated five flights in 2010 (total 5 hours) and four flights in 2011 (total 4.8 hours). Prior to the accident, the pilot had logged 290.4 total hours, with the majority in the accident airplane.
Aircraft Information
The airplane was a 1972 single-engine, low-wing, fixed landing gear Grumman AA-1B, powered by a 115-horsepower Lycoming O-235-C2C engine driving a two-blade metal McCauley propeller. It held a standard airworthiness certificate in normal and utility categories. The airframe’s annual inspection on September 14, 2012, recorded a tachometer time of 2,060 hours, total airframe time of 2,303 hours, and 2,329 hours since the engine’s last major overhaul. The inspection entry included a note advising the owner that the ELT battery was overdue.
Meteorological Information
At 1315, the automated weather reporting facility at KBUU reported wind from 170 degrees at 8 knots, variable between 150 and 210 degrees, visibility 10 miles, clear sky, temperature 54°F, dew point 34°F, and barometric pressure 30.35 inches of mercury.
Airport Information
Burlington Municipal Airport is a publicly owned, non-towered airport with a CTAF. It has two runways: an asphalt runway (11/29) and a turf runway (1/19). The prevailing wind favored takeoffs and landings on runways 19 and 11.
Wreckage and Impact Information
The accident site was located in a muddy, cultivated field about 1/4 nautical mile west-southwest of the runway 11 threshold. The wreckage was approximately 20 degrees right of the runway’s extended centerline, aligned with a magnetic heading of 092 degrees. The initial impact crater contained the engine, propeller, and most cockpit instrumentation, with the main wreckage two feet west of the crater. Impact signatures were consistent with a nose-low impact. The fuselage was torn and broken forward of the pilot seat; both wings exhibited accordion crushing. The right wing was fractured at the wing root, though the aileron and flap remained attached. The fuselage and empennage were buckled and distorted, while the vertical stabilizer, horizontal stabilizers, rudder, and elevators were unremarkable. The fuel tank was breached, and fuel odor and residue were present in the soil. Cockpit controls were destroyed, and flight control continuity was confirmed from controls to surfaces. Cockpit instrumentation separated from their mounts and did not provide reliable readings.
The emergency locator transmitter (ELT), an ACK Technologies E-01-01, was found behind the pilot seat, not installed in the airplane. Its RJ-11 cord was plugged into the ELT, but the external coaxial antenna was not connected, and the switch was in the off position. Handwriting consistent with the pilot’s indicated batteries were installed on October 8, 2012. Law enforcement and first responders did not report handling the ELT, and a photo taken about 20 minutes after the accident showed it in the same condition.
The propeller remained attached to the engine; the aluminum nose cone was crushed rearward into the hub and distorted opposite blade rotation. Blade A showed leading edge polishing, s-bending, and aft deformation; Blade B was slightly bent aft.
Engine examination revealed that the top spark plugs had light gray coloring, consistent with a lean fuel burn. Engine continuity was confirmed, and thumb compression was noted on each cylinder. The carburetor was fragmented, with damage to the fuel inlet screen housing; the inlet screen was not recovered. The oil screen was free of obstructions. No preimpact anomalies were detected.
Medical and Pathological Information
An autopsy conducted by the Walworth County Coroner’s Office listed the cause of death as massive trauma from the crash. The autopsy noted the presence of cardiomegaly. Forensic toxicology by the FAA Bioaeronautical Sciences Research Laboratory detected no carbon monoxide, cyanide, ethanol, or drugs.
Additional Information
A Lowrance Airmap 2000c GPS found in the wreckage recorded several flights, none consistent with the accident flight. An excerpt from the FAA’s “Airplane Flying Handbook” (2004) described accelerated maneuver stalls, noting that stalls resulting from abrupt maneuvers can be more severe and may occur at higher airspeeds or lower pitch attitudes, potentially unexpected by inexperienced pilots. The NTSB issued Safety Alert SA-019 in March 2013, addressing prevention of aerodynamic stalls at low altitude.