NTSB Releases Docket Info on Philly Learjet Accident

The NTSB has opened the docket on the crash of a medevac Learjet 55 on Jan. 31, 2025, in Philadelphia. Eight people died as a result of the accident, including six on board the airplane and two people on the ground (one died in April 2025 as a result of injuries suffered in the accident).

The Learjet took off from Northeast Philadelphia Airport (KPNE) at 18:06 local time, heading to Missouri’s Springfield-Branson National Airport (KSGF). After takeoff, the Learjet climbed into an overcast layer of clouds at 400 feet agl, according to the NTSB, at 2,300 fpm and 191 knots calibrated airspeed. The rate of climb decreased, and it began to descend from 1,650 feet msl at 18:06:56. The last ADS-B data point was recorded at 18:07:03, and at that point the Learjet was descending at 10,000 fpm, with the calibrated airspeed continuing to increase, “reaching 300 knots at the end of the ADS-B data,” the NTSB reported.

“The airplane was rolling left at a rate of -2 degrees/second for about 25 seconds, but the magnitude of the roll rate began to increase about 18:06:50, about 6 seconds before the airplane began to descend. The calculated roll angle exceeded 90 degrees left wing down about 18:07:00. Between 18:06:29 and 18:06:59, the magnitude of the roll acceleration was less than 2 degrees/second. The calculated pitch angle was initially near 12 degrees, but it began to decrease about 18:06:38, and it passed through zero about 18:06:57, when the airplane began to descend. 

“The increasing speed throughout the flight was reflected in a positive longitudinal load factor, which rotated the gravito-inertial force (GIF) vector forward, leading to an apparent GIF pitch that was positive throughout the flight. At 18:07:01, the actual pitch angle was calculated to be -18.6 degrees, but the apparent GIF pitch was calculated to be 23.7 degrees.”

As the NTSB further explained, “The apparent [GIF] pitch is positive and greater than the actual pitch for the entire flight. Even as the airplane began its steep descent, the apparent pitch increased while the actual pitch dropped below 0, owing to the increased acceleration along the body…axis.”

While not posing any conclusions, as it will in the final report, the NTSB did note that “Sustained forward acceleration can lead to a form of spatial disorientation known as somatogravic illusion, because the vestibular system cannot distinguish the acceleration of translational motion from the acceleration of gravity.”

In another note that highlights a possible factor in the investigation, the NTSB summarized information about the Learjet’s pitch trim setting. The weight and balance report showed that the takeoff center of gravity was about 2 inches aft of the forward CG limit at the takeoff weight of 20,830 pounds (mtow is 21,500 pounds).

“According to the manufacturer, a fully extended (nose-down pitch) measurement is 18.77 ± 0.030 inches. A fully retracted (nose-up pitch) would measure 13.87 ± 0.030 inches. The pitch trim actuator was measured at 17.3141 inches; according to the manufacturer, this equates to 3.97 trim units on the cockpit pitch trim indicator, where 1 is full nose-down trim, and 11 is full nose-up trim. The take-off trim ‘green' band is between 4 and 8 units of trim.

“Based on the measurements obtained and physical observations during the actuator disassembly, it was concluded that the measured extension of the actuator was the extension immediately prior to impact. Checklists found in the wreckage indicate that with the 16.85% MAC [mean aerodynamic chord], noted on the accident flight weight and balance provided by the operator, the takeoff pitch trim should have been set to 5.6 degrees.” 

The Learjet 55 was owned by Air Lease International of Guadalajara, Mexico, and operated by Med Jets, which is also based in Guadalajara.