2 fatalities

2023-06-03: Piper PA-31-310 Navajo (N4077W) — Charles Montgomery — Tupelo, United States of America

Tupelo, United States of AmericaTakeoff (climb)

On June 3, 2023, a Piper PA-31-310 Navajo (registration N4077W) operated by Charles Montgomery was involved in an aviation accident near Tupelo, United States of America during takeoff. 2 people were killed. Investigators recorded the probable cause as: The pilot's exceedance of the airplane's critical angle of attack while maneuvering after takeoff for reasons that could not be determined, which resulted in an aerodynamic stall and subsequent loss of control. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A).

Sourcesthe Bureau of Aircraft Accidents Archives (B3A)Primary reportUpdated 1781189304Data APIEditorial standards

A multi-engine airplane on an IFR flight stalled and crashed after a steep right turn at low altitude, resulting in a postimpact fire. Investigation could not determine why the pilot conducted the turn.

Accident Overview

On an instrument flight rules departure, a multi-engine airplane carrying a pilot and a pilot-rated passenger experienced a loss of control shortly after takeoff. According to ADS-B data, the airplane entered a climbing right turn, reaching a peak altitude of about 300 feet above ground level and a highest ground speed of approximately 102 knots. The turn then became descending and tightening as speed decreased.

Flight Path and Aerodynamic Conditions

Analysis of ADS-B data revealed that the airplane's bank angle during the turn was initially about 42°, with a load factor of 1.36g. As the turn continued, the bank angle increased to about 46° and the load factor rose to 1.44g. Under these conditions, the airplane's stall speed would have been approximately 77 knots calibrated airspeed. The last calculated true airspeed was about 81 knots.

Impact and Fire

The airplane impacted terrain adjacent to the airport and was consumed by a postimpact fire.

Engine and Systems Examination

Examination of both engines found no evidence of preimpact mechanical malfunctions, though the scope was limited due to fire damage. A sound spectrum study from surveillance video indicated that at least one engine was operating at about 2,550 rpm throughout the takeoff and right turn; however, it could not distinguish whether both engines were running at the same rpm. The flight control system showed no anomalies. An aileron balance cable was found separated from a swaged terminal, with a portion of the cable missing. Metallurgical examination indicated the separation was consistent with being cut, most likely during wreckage recovery or the accident sequence.

Toxicology

Toxicological testing found ethanol and n-propanol in the pilot's specimens. While alcohol consumption could not be excluded, at least some of the ethanol was likely from postmortem production. The passenger's toxicology revealed the potentially sedating antihistamine cetirizine in muscle and liver tissue; however, whether the passenger experienced impairing effects could not be determined.

Conclusion

Based on available information, it is likely that the pilot exceeded the airplane's critical angle of attack while maneuvering immediately after takeoff, resulting in a loss of control and impact with terrain. The circumstances that led to the pilot's decision to conduct the steep right turn at low altitude could not be determined.

Probable cause

The pilot's exceedance of the airplane's critical angle of attack while maneuvering after takeoff for reasons that could not be determined, which resulted in an aerodynamic stall and subsequent loss of control.