Philly Learjet Crash: NTSB Docket Reveals Possible Role of Spatial Disorientation and Pitch Trim
The NTSB has released its docket information on the January 31, 2025 crash of a medevac Learjet 55 in Philadelphia, providing new details about the final seconds of the flight.
Eight people ultimately died in the accident — six aboard the Learjet and two people on the ground, including one victim who died in April 2025 from injuries sustained in the crash.
The Learjet departed Northeast Philadelphia Airport at 18:06 local time for Springfield-Branson National Airport in Missouri. After climbing through an overcast layer, the aircraft reached about 1,650 feet before its flight path rapidly deteriorated.
According to the NTSB, the aircraft began rolling left before entering a steep descent. Its calculated roll angle exceeded 90 degrees left wing down, while its descent rate reached 10,000 feet per minute. Airspeed continued increasing, reaching about 300 knots in the final ADS-B data.
Investigators highlighted a potentially critical phenomenon: somatogravic illusion.
As the Learjet accelerated forward, the resulting forces could have made the pilots perceive the aircraft as pitching up even while its actual nose attitude was falling. At one point, the NTSB calculated the actual pitch at -18.6 degrees, while the apparent pitch perceived through the gravito-inertial forces was +23.7 degrees.
The NTSB stressed that it has not reached a final conclusion, but noted that sustained forward acceleration can cause spatial disorientation because the human vestibular system cannot distinguish translational acceleration from gravity.
Investigators are also examining the aircraft’s pitch-trim setting.
The Learjet’s pitch-trim actuator measured 17.3141 inches, corresponding to approximately 3.97 trim units. The manufacturer’s takeoff trim range was 4 to 8 units, while the checklist indicated that, based on the aircraft’s weight and balance, the takeoff pitch trim should have been set to 5.6 units.
The aircraft, owned by Air Lease International of Guadalajara, Mexico, was operated by Med Jets.
