A severed electrical wire prevented a FedEx Boeing 757-200 freighter from deploying its landing gear, forcing pilots to execute a rare gear-up landing last year, according to the National Transportation Safety Board (NTSB). The incident, which resulted in no injuries, highlights a hidden maintenance challenge in aging aircraft wiring systems.
Hydraulic Failure Triggers Emergency
The sequence began just 22 seconds after takeoff from Chattanooga Metropolitan Airport when a fatigued hydraulic hose ruptured on the left main landing gear door actuator. This failure depleted pressure in the primary extension system, leaving the crew unable to lower the landing gear through normal procedures. The pilots immediately initiated troubleshooting and decided to return to the departure airport.
Backup System Also Failed
When the primary system proved inoperable, the flight crew attempted to activate the alternate gear extension method. However, investigators found a complete break in a critical wire between the alternate system’s switch and its power pack. The NTSB report states the wire failure prevented electrical continuity, meaning the backup mechanism couldn’t release the gear doors to allow gravity-assisted deployment.
Hidden Wiring Defect Eluded Detection
The broken wire was part of an enclosed bundle, making visual inspection nearly impossible during routine maintenance. “The probability that personnel would have detected this break was low,” the NTSB concluded. The fracture pattern suggested gradual fatigue from tensile loading rather than sudden damage. This finding raises questions about wiring inspection protocols in older aircraft like the 757, which first entered service in the 1980s.
Controlled Belly Landing Executed
With no landing gear options remaining, the crew skillfully guided the 757 onto Runway 20. The aircraft first contacted the surface with its left Rolls-Royce RB211 engine approximately 1,650 feet from the threshold, followed by right engine contact 735 feet later. The aft fuselage began scraping another 2,000 feet down the runway before the freighter overran the end by 830 feet. Remarkably, the pilots maintained control throughout the incident, and no post-crash fire occurred.
Maintenance Practices Under Review
The NTSB’s findings have prompted renewed scrutiny of wiring maintenance in older cargo aircraft, which often remain in service decades beyond original design expectations. While the immediate cause was mechanical, the hidden electrical fault that prevented backup system operation represents a secondary failure mode that safety experts say deserves greater attention in maintenance programs.
FedEx and Boeing are reviewing the findings as the aviation industry continues addressing challenges posed by aging aircraft systems. The NTSB plans to issue formal safety recommendations aimed at improving detection of similar latent wiring faults before they can affect flight safety.
