Federal authorities have disclosed that a tragic plane crash near a suburban Philadelphia middle school, claiming two lives, was the result of a stall and loss of control during instructional flight maneuvers.

In its recent final report, the National Transportation Safety Board revealed that the Beech 35-C33, a four-seat aircraft, crashed in Bucks County’s Hilltown Township in February 2022 while the pilot was training for a commercial pilot practical examination alongside an instructor.

The crash’s probable cause was attributed to the pilots exceeding the airplane’s critical angle of attack during maneuvers at approximately 1,600 feet above the ground, resulting in an aerodynamic stall and loss of control.

Both the pilot, 55-year-old Brian Filippini of Philadelphia, and the instructor, 74-year-old Alfred George Piranian of Chalfont, suffered multiple blunt-force injuries and lost their lives. Investigators could not ascertain whether a heart attack suffered by the instructor three weeks prior played a role in the accident.

The pilot had approximately 733 hours of flying experience, while the instructor had accumulated about 11,500 hours, with roughly 8,000 of those hours spent providing flight instruction, according to the report.

The aircraft crashed in close proximity to Pennridge Central Middle School, with the impact causing a propeller blade to detach and land in a nearby residence, as noted in the safety board’s report.