What caused the right main landing wheel to lock up, forcing a single-engine light airplane to flip over at Dillingham Airfield on Oahu in November remains undetermined, according to federal investigators.

But it is possible the locked brake and wheel might have been jammed by a rock or other foreign object, according to findings released Thursday by the National Transportation Safety Board.

The pilot of a Cessna 305, operated by the Honolulu Soaring Club, suffered minor injuries in the accident on Nov. 7, but the airplane sustained substantial damage, according to investigators.

Investigators confirmed the right brake was locked and the tire would not rotate properly. After the airplane was recovered and taken to a hangar, the right brake was disassembled and no irregularities were discovered, the investigation found. After reassembly, the brake was operational.

"It is possible that the wheel/brake may have been jammed by a rock or other foreign object, which was dislodged during the recovery," an inspector reported.

The pilot said shortly after landing the airplane veered right and pitched forward, flipping over on its back.