Accident Summary
The accident occurred during a flight intended for an instructor pilot to administer second-in-command (SIC) flight training to a commercial pilot in a twin-engine aircraft. The training manual specified that SIC training included 4 hours of normal and emergency flight maneuvers, including stalls in the landing and takeoff configuration and while turning at a 15–30 degree bank. It is unknown which pilot was flying the airplane at the time of the accident.
Witness Observations
A witness first heard the airplane's engines and observed it from her driveway. She stated that as the engine noise grew louder, she spotted the airplane spiraling downward. Although she thought the airplane was performing aerobatics, it was getting too close to the ground. She then heard a loud thud, followed approximately 3 seconds later by a loud boom and the appearance of black smoke. Another witness reported seeing the airplane "going nose first straight down and spinning...counterclockwise." She also thought the airplane was performing aerobatic maneuvers but noted that it did not stop descending. The airplane disappeared behind trees, after which the witness heard a loud explosion and saw smoke. She added that she had not observed what the airplane was doing prior to seeing it in a "downward spiral."
Radar Data
Radar data indicated that the airplane was at 8,400 feet msl for the last 2 minutes and 26 seconds of the flight. The recorded ground speed during that period fluctuated between 75 and 59 knots. The final radar returns showed the airplane making a 180-degree turn before radar contact was lost. No mayday calls were received from the airplane.
Post-Accident Examination
The airplane impacted the ground in a near wings-level attitude and was consumed by a post-crash fire. A post-accident examination revealed no anomalies with the airplane or its engines.
Probable Cause
The flight instructor's failure to maintain aircraft control while practicing stall maneuvers, which resulted in an inadvertent spin.