Douglas C-54 Skymaster accident at Washington-Ronald Reagan-National, United States of America, 12 Sept 1946 (N91068)
On September 12, 1946, a Douglas C-54 Skymaster (registration N91068) operated by Pennsylvania Central Air Lines was involved in an aviation accident near Washington-Ronald Reagan-National, United States of America during landing or approach. No fatalities were reported. Investigators recorded the probable cause as: The Board determines that the probable cause of this accident was the failure in the No. 4 engine of the exhaust valve of the No. 2 cylinder and the exhaust connection of the No. 1 cylinder which resulted in fire in flight. This summary draws on records from the Bureau of Aircraft Accidents Archives (B3A); 2 related events involving the same aircraft type or operator are linked below.
Probable cause
The Board determines that the probable cause of this accident was the failure in the No. 4 engine of the exhaust valve of the No. 2 cylinder and the exhaust connection of the No. 1 cylinder which resulted in fire in flight. A contributing factor was the inadequacy of the seal between the firewall and nacelle skin and between individual cowl panels which permitted the fire eventually to reach Zone 3 and to become uncontrollable.
— NTSB Determination
Accident narrative
The crew was performing a local training flight from Washington-National Airport. Enroute, the engine number four caught fire and the crew was unable to extinguish the fire. The captain informed ATC about his situation and obtained the authorization to return to Washington-National Airport for an emergency landing. On final approach to runway 33, the engine number four separated from the wing. Despite the situation, the crew was able to continue the approach and landed safely. While all four crew members were unhurt, the aircraft was considered as damaged beyond repair due to the severity of the damages that the right wing suffered due to fire.
Probable cause (official findings): The Board determines that the probable cause of this accident was the failure in the No. 4 engine of the exhaust valve of the No. 2 cylinder and the exhaust connection of the No. 1 cylinder which resulted in fire in flight. A contributing factor was the inadequacy of the seal between the firewall and nacelle skin and between individual cowl panels which permitted the fire eventually to reach Zone 3 and to become uncontrollable.