On April 2, 1988, a North American T-6G (registration N9871C) was involved in an aviation accident near Stockbridge, GA. Investigators recorded the probable cause as: Brake fluid leakage onto the brake shoe caused the shoe to expand and lock the wheel. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An airplane nosed over during landing roll after the left wheel locked. Post-crash examination revealed no mechanical failure; the pilot reported brake fluid leakage caused brake shoe expansion and wheel lock.
Event
The aircraft touched down with the left wheel locked. During the landing roll, the airplane nosed over.
Investigation
Post-crash examination revealed that the left wheel could not be rotated forward by hand; it could be rotated aft only with considerable effort. The hydraulic brake line was disconnected from the left brake assembly, but the wheel remained locked in the forward direction. The brake assembly was disassembled. Disassembly showed no evidence of mechanical failure or malfunction. The pilot indicated that brake fluid had leaked onto the brake shoe, causing it to expand and lock the wheel.
Probable cause
Brake fluid leakage onto the brake shoe caused the shoe to expand and lock the wheel.