History of Flight
On 13 April 2015, Jet Airways flight 9W-2423, a Boeing 737-800 (registration VT-JGA), was operating a scheduled passenger service from Delhi to Khajuraho via Varanasi. The aircraft carried 59 passengers and 8 crew members, including 2 cockpit crew, 5 cabin crew, and 1 aircraft maintenance engineer. The pilot-in-command held an Airline Transport Pilot Licence, and the co-pilot held a Commercial Pilot Licence.
The flight departed Varanasi at 0715 UTC and proceeded normally to Khajuraho. The pilot-in-command executed an Instrument Landing System approach to Runway 19. Landing gear extension and flap selection occurred at appropriate altitudes. Touchdown occurred with a pitch of 4.39 degrees, vertical acceleration of 1.65 G, and speed of 120 knots. Approximately 15 seconds after touchdown, at a speed of 36 knots, the left main landing gear aft trunnion pin fractured, causing the aircraft to veer left of the centerline. The aircraft came to rest on the runway, supported by the left engine, nose gear, and right main landing gear. Hydraulic fluid leaked from the damaged left main landing gear.
Emergency evacuation was conducted on the runway. All four main door escape slides and four over-wing emergency windows were deployed. Passengers used two escape slides (L1 and R1). One cabin crew member sustained minor bruises during evacuation. No fire occurred, and no fire extinguisher was used. The runway was closed due to the disabled aircraft. An Air India A-320 that had landed earlier remained stuck at the airport until the disabled aircraft was removed on 16 April 2015 at 1115 UTC.
Damage to Aircraft
The aircraft incurred substantial damage. The left main landing gear aft trunnion pin was sheared off. The aft end of the left main landing gear traveled upward, puncturing composite panels and protruding above the aft wing surface. The walking beam became visible above the wing. Damage was limited to composite panels and non-structural support frames; the support beam was damaged due to landing gear travel. Additionally, the hangar link assembly drifted, the hangar link mount dislocated, the side strut assembly twisted, the door attachment bracket and door were damaged, and the main landing gear stub beam (a structural member between the aft spar and the main landing gear support beam lower forward attach lug) was ripped off. The aircraft rested on the left engine.
Injuries to Persons
No fatal or serious injuries were reported. One cabin crew member received minor injuries (bruises). All other crew and passengers were uninjured.
Probable Cause
The investigation determined that the left aft landing gear trunnion pin failed due to overload following fatigue growth. Crack initiation occurred in the heat-affected area where excessive grinding was performed during overhaul. Initial crack growth was characterized by intergranular cracking, assisted by a hydrogen embrittlement mechanism, until fatigue took over.
Additional Information
The aircraft had completed three sectors on the day of the accident: Bengaluru–Delhi, Delhi–Varanasi, and Varanasi–Khajuraho. Air traffic control observed a normal touchdown near the Precision Approach Path Indicator. After the pilot reported a possible landing gear collapse, emergency services were dispatched.