J3 Cub
Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 155; Flight Crew Total 1220; Flight Crew Type 0
Situational Awareness
Aircraft Equipment Problem Critical; Ground Event / Encounter Loss Of Aircraft Control; Ground Event / Encounter Object
Aircraft Aircraft Damaged; Flight Crew Regained Aircraft Control; Flight Crew Took Evasive Action; General Maintenance Action
Human Factors; Aircraft; Procedure
Ground run and engine check of newly rebuilt Piper Cub with original engine without starter. I was tasked with holding the brakes while the engine was hand Propped. Once the engine turned over it went to high RPM and jumped up and right. The owner propping the aircraft moved out of the way as I applied both brakes full to no effect; I jammed the throttle all the way to the idle position and pulled the mixture to cutoff just as the right wing struck the adjacent hangar and swung the prop into the hangar door. The aircraft and prop stopped after striking the hangar door as I was reaching for the Mag switch. No injuries occurred; the hangar door will need a cross beam welded and two sheet metal panels replaced. The aircraft inside the hangar received minor dings on the nose spinner where the sheet metal from the hangar contacted it inside the hangar. The Cub prop is beyond repair and the right strobe light was broken; on initial inspection; there was no further damage done and we estimate less than $1;000 to repair the hangar and aircraft in the hangar. The cub prop will need to be replaced and the engine crank was tested and found to be within tolerance.
The Pilot of a Piper cub was holding the brakes while another pilot hand propped the engine. The brake system malfunctioned; which caused the aircraft to contact a hanger.