On December 20, 2024, at about 23:15 local time, a Raytheon (Beech) C90A King Air, N438CA, was substantially damaged in a ground collision at Daniel K. Inouye International Airport, Honolulu.
Just after engine start, the airplane rolled forward without either pilot commanding or noticing it. It struck an unoccupied company airplane parked about 50 to 75 feet across the ramp, substantially damaging its right engine firewall and engine mounts.
Both pilots said the ramp was very dark. The pilot-in-command said the parking brake was set and he was holding the toe brakes during both engine starts. The second-in-command confirmed the parking brake was set before the wheel chocks were removed. The airplane stayed still after the right engine started. During the left engine start, the pilot-in-command didn’t notice any movement until just before impact. The second-in-command had looked down to adjust his shoulder harness and didn’t notice the movement at all.
FAA inspectors found adequate brake fluid and no air in the system. The brakes and parking brake worked normally from both seats, and the only finding was a minor trace of fluid beneath the parking brake valve. However, the airplane had received an exterior wash and engine compressor rinse before the flight. After the accident, another company pilot flying the same model reported reduced braking for about half a mile of taxi after a similar wash.
The NTSB determined the probable cause was a temporary loss of braking effectiveness after the exterior wash. The crew’s delayed recognition of the movement in low light contributed. The operator now requires wheel and brake assemblies to be rinsed with fresh water, dried, and inspected after washes.
Photo source: NTSB Docket