The Aug. 21, 2021, Gulfstream GIV accident as a result of the separation of the aircraft's nose landing gear pip pin was attributed to a lack of communication between the pilot-in-command (PIC), second-in-command (SIC), and ground crew, according to the National Transportation Safety Board's (NTSB’s) investigation final report.
During the takeoff roll from Florida’s Fort Lauderdale Executive Airport, the PIC and SIC, and a non-type-rated observer pilot, reported that near 100 knots, the nose gear developed a “violent shimmy.” As the PIC aborted the takeoff, the gear separated from the airframe. The airplane veered off the runway, and the right wing and right main landing gear struck approach lights, which resulted in substantial damage. All 14 occupants escaped uninjured.
“The PIC and SIC failure during preflight inspection to ensure that the nose landing gear’s pip pin was properly installed, which resulted in separation of the pip pin during takeoff” and loss of the nose landing gear was the cause of the accident, the report said. Contributing to the accident was the ground crew supervisor’s “failure to inform the PIC or SIC of the anomaly concerning the pip pin following a towing operation.”
After towing the aircraft before the flight crew’s arrival, ground personnel was unable to get the plunger button and locking balls of the nose gear’s removable pip pin to release, and the locking balls remained retracted. The ground crew re-installed the pip pin through the steering collar with the upper torque link arm connected. “However, with the locking balls in the retracted position, the pin was not secured in position as it should have been,” said the report.
Ground personnel left the safety clip hanging from its lanyard on the gear, and a ground supervisor told the first arriving crewmember (the observer pilot), “Per tow team, check your nose pin.” But all three pilots denied that any ground personnel told them about issues with the gear. The report did not address this discrepancy.