Overview
On March 2, 2012, at approximately 1420 central standard time, a Piper PA-30, registration N373JT, experienced a collapse of its main landing gear during landing on runway 36 at Northwest Regional Airport (52F), near Roanoke, Texas. The private pilot, who was the sole occupant, reported no injuries. The airplane sustained substantial spar damage. The aircraft was registered to and operated by the pilot under 14 Code of Federal Regulations Part 91 as a personal flight.
Flight Details
The flight originated from Crystal City Municipal Airport, near Crystal City, Texas, at about 1300, with a planned destination of Denton Municipal Airport (DTO), near Denton, Texas. Day visual flight rules (VFR) conditions prevailed, and no VFR flight plan was filed. During the flight, the pilot diverted to Northwest Regional Airport due to electrical system issues.
Electrical Issues
According to the pilot's statement, the alternators were producing approximately nine volts of output during the flight. The pilot switched the generators off and on multiple times but could not achieve more than eight to nine volts. Intermittent global positioning system (GPS) operation occurred, and a "squeal" was heard in the radio. The pilot noted that the noise stopped when the right alternator was switched off. Eventually, radio communication capability was lost while en route to Denton Municipal Airport.
Landing and Collapse
The pilot diverted to Northwest Regional Airport and lowered the landing gear on downwind. He observed that the nose landing gear was extended by its reflection in the spinner. The landing rollout was described as "normal" until the right main landing gear collapsed, followed by the left main landing gear. The pilot commented that the alternator failure likely resulted in insufficient battery power to lock the gear in place.
Emergency Procedures
The PA-30 flight manual included an emergency procedure for landing gear extension. The procedure specified reducing airspeed to not exceed 100 mph. Full travel of the extension handle or a green light indicates gear extension. An operational note indicated that reducing power and rocking the gear extension handle aids manual extension.
Inspection Findings
A Federal Aviation Administration inspector reported no evidence of mechanical malfunctions or failures that would have precluded normal landing gear operation.