Accident Details
On June 1, 2011, at approximately 1640 Pacific daylight time, a Cessna 340A, registration N340BG, sustained substantial damage when its nose gear collapsed and deformed primary airframe structure in the wheel well. The event occurred after the pilot lost directional control while taxiing off runway 24 following an uneventful landing at Fullerton Municipal Airport (FUL), Fullerton, California. Neither the airline transport certificated pilot nor the passenger was injured.
Flight Information
The airplane was registered to and operated by Humanitarian Airlift International, based in Coto de Caza, California. The flight was conducted as a personal flight under 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed. The airplane had departed Riverside, California, at approximately 1545.
Pilot's Account
According to the pilot, the flight was a repositioning after maintenance. No mechanical anomalies were noted during the flight, and the landing at FUL was normal. Near the completion of the landing rollout, with normal and effective braking, the pilot initiated a turn off the runway. During this turn, the left brake system failed, causing the airplane to veer into soft dirt adjacent to the runway. The nose wheel dug into the dirt and collapsed.
Post-Accident Examination
An airframe and powerplant mechanic examined the airplane and found a broken weld in the left engine's oil return line. The weld was located adjacent to the line's outlet nipple at the rear engine case. The line was routed from the vacuum pump air-oil separator to the case. Leaking oil from this broken weld had coated the rear engine case and the left main landing gear brake assembly. According to the mechanic, engine oil on the left gear and wheel/brake assembly caused braking action on the left brake to be reduced to zero. The weld break appeared related to fatigue.
Damage
The nose gear collapse resulted in substantial damage to the airframe structure in the wheel well.