Champion Citabria Undifferentiated
Flight Crew Private
Flight Crew Last 90 Days 0; Flight Crew Total 2500; Flight Crew Type 1500
Human-Machine Interface; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Loss Of Aircraft Control; Ground Event / Encounter Object
Aircraft Aircraft Damaged
Aircraft; Human Factors
Sequence of events: Aircraft was out of service for extended time waiting for parts in annual inspection. Pilot arrived at airport in order to take possession of aircraft. Engine started normally; and then began to stumble. Pilot manipulated mixture and throttle in attempt to correct; without success. Pilot cycled fuel cutoff with no immediate effect. Pilot returned to manipulation of mixture; when engine power increased dramatically; overpowering brakes and taxiing aircraft into hangar door. Pilot's interpretation: The aircraft is 1946 Aeronca Champ with fuel shutoff located low on left side of cockpit. Substantial play in the handle makes it difficult or impossible to visually determine whether it is on or off. Consequently; pilot never activates fuel shutoff in normal operation. Conversation with Mechanic after event suggests that fuel shutoff may have been activated after annual inspection unbeknownst to pilot. Pilot's current opinion is that fuel shutoff led to engine stumble. Cycling the fuel cutoff led to delayed engine surge not controlled by mixture full lean setting applied. Brakes were insufficient to stop aircraft before contact with hangar door. Position of throttle during event is unknown; although the behavior of the engine suggests other than an idle setting. Corrective actions: Routine cycling of fuel cutoff before start.
Champ pilot experiences a rough running engine after an extended down time waiting for parts. The fuel selector; throttle and mixture are all manipulated without immediate effect. Suddenly engine power increases dramatically and the aircraft cannot be controlled before contact with the hangar door occurs.