Piper PA-12 N7556H accident near Mount Holly, New Jersey

Probable cause

A loss of directional control during landing for undetermined reasons.

NTSB analysis

The pilot stated that after he lowered the tailwheel to the runway on landing, the airplane became "squirrely" and veered to the left. He attempted to correct the trajectory with the application of "full left rudder and brake," but the airplane departed the dry paved surface of the 50-foot-wide runway and ground-looped in the grass on the left side of the runway. The pilot believed that the non-pilot-rated passenger had inadvertently interfered with the airplane controls, but the passenger denied any interference. A Federal Aviation Administration (FAA) inspector examined the airplane and stated that the tailwheel centering mechanism was "weak," and could "easily" be moved out of the centered position. An FAA-conducted functional check of the left brake system determined that the system operated normally. The right braking system was damaged in the accident, which precluded a functional check, but the FAA inspector reported that a visual check did not reveal any preaccident failures.

Text from the NTSB. Open the NTSB docket for ERA09LA468 for the full record.