What happened
On August 21, 2021, a GULFSTREAM AEROSPACE G-IV, registration N277GM, was involved in an accident during takeoff from runway 9 at Fort Lauderdale Executive Airport (FXE). The flight was being operated as a Part 91 personal flight with 4 crewmembers and 10 passengers on board.
During the takeoff roll, as the aircraft reached approximately 100 to 110 knots, the pilot in command (PIC) experienced a severe shimmy. The pilot attempted an aborted takeoff using braking and thrust reversers. During the deceleration, the nose landing gear separated from the aircraft. The airplane veered off the runway, causing the right main landing gear and right wing to strike a concrete slab used for approach lighting. The aircraft came to a stop in a sandy grass area approximately 200 feet right of the runway centerline. There were no injuries to the 14 people on board.
The investigation
Investigators examined the runway environment and the wreckage. The nose landing gear (NLG) components were found scattered along the runway, with the pip pin located 2,21ered feet from the main wreckage. The right main landing gear had punctured upward into the inboard aft section of the right wing.
Post-accident testing of the NLG and its pins showed no mechanical malfunctions. However, investigators found that the NLG and pip pin were missing the second lanyard, safety clip, and handle required by Gulfstream technical publications.
Interviews with ground personnel revealed that during a towing operation hours before the flight, the ground crew encountered an issue with the pip pin. The plunger button and locking balls were stuck in the depressed position. Unable to release the button by shaking or tapping the pin, the crew re-installed the pin without being able to insert the safety pin. They left the safety pin hanging from its lanyard on the side of the NLG.
While a ramp supervisor reported telling the first arriving crewmember (an observer pilot) to check the nose pin, the flight crew members—the PIC and the second-in-command (SIC)—reported they were not informed of any issues with the NLG pins. The observer pilot stated he was on a telephone call when the ramp personnel approached him and did not recall being told about a specific gear anomaly.
Findings
- The pip pin likely moved outward and fell from its position because the locking balls were not extended to secure it.
- This movement allowed the upper torque link arm to move freely, causing the violent shimmy and subsequent separation of the nose landing gear.
- The ground crew failed to discard the malfunctioning pip pin as required by the airplane's handling handbook.
- The ground crew failed to directly notify the PIC or SIC of the anomaly following the towing operation.
- The flight crew failed to notice that the safety pin was not properly installed during the preflight inspection.