Accident Overview
On April 2, 2022, at 1119 eastern daylight time, a Learjet Inc 45, registration N877W, was substantially damaged during a landing accident at Morristown Municipal Airport (MMU), Morristown, New Jersey. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The two airline transport pilots and two passengers sustained minor injuries.
Landing Sequence
According to the captain, who was pilot flying, the airplane was established on a visual approach to runway 23. Reported wind was from 340° at 3 knots gusting to 16 knots. The quartering tailwind was computed within limits. At touchdown, thrust reversers were deployed, and the airplane turned sharply to the right. The captain reported that normal crosswind correction inputs made no difference, and extreme inputs still provided no control. The airplane departed the right side of the runway; the entire wing structure separated from the main fuselage, which continued about 100 ft before coming to rest upright. Crew and one passenger exited via the main cabin door; the second passenger used the emergency exit.
Examination of Data and Video
Flight track data and airport surveillance video showed a normal approach profile, with the airplane crossing the runway threshold at about 120 knots groundspeed. About 9 seconds into the landing roll, the airplane turned sharply right and departed the runway. Thrust reversers on each engine were deployed and approximately matched. A windsock visible in the video was nearly parallel to the ground, indicating nearly a direct crosswind from the right toward the airplane.
Accident Site and Wreckage Examination
An FAA aviation safety inspector photographed the accident site and completed a cursory examination. Runway skid marks began about 1,200 ft from the approach end of runway 23 and arced right about 560 ft before transitioning to grass tracks. The wreckage was later examined at a facility in Clayton, Delaware, by a team supervised by NTSB aerospace engineers.
Cockpit Voice Recorder Review
The CVR was reviewed by an NTSB Recorder Specialist. The crew had listened to ATIS at MMU and were aware of wind speed, direction, and low-level windshear warnings. They questioned why runway 23 was in use when winds favored runway 05. The air traffic controller explained that due to a runway closure at Newark International Airport (EWR), use of runway 05 at MMU allowed improved conflict resolution and traffic flow at EWR.
Component Testing
Both engines operated normally per DEEC data. The yaw force sensors were tested; the copilot’s sensor failed the Output Balance Error element in tension and compression. Nosewheel steering rudder pedal systems functioned as designed with no significant faults. The brake control unit and wheel speed transducers passed tests; BCU data lacked date/time stamps and could not be correlated to the accident. The nose wheel steering electronic control unit and spoiler control electronics unit showed no faults.
Reference to FAA Handbook
The FAA Airplane Flying Handbook notes that the landing process continues until the airplane decelerates to taxi speed or stops, and that pilots should maintain positive control after touchdown. Loss of directional control may lead to a ground loop, which can cause the airplane to tip and collapse the landing gear.