Accident Overview
On August 24, 2016, at approximately 1830 central daylight time, a Beech E-55, registration N855T, made a gear-up landing on runway 17 at Sheppard Air Force Base/Wichita Falls Municipal Airport (SPS), Wichita Falls, Texas. The airplane sustained substantial damage to the bottom fuselage structure. The two occupants, a flight instructor and a commercial-rated dual student pilot, were uninjured.
Flight Details
The aircraft was registered to and operated by Cobra Kai Inc (doing business as Cobra Kai Flight Academy) under 14 Code of Federal Regulations Part 141 as an instructional flight operating on an instrument flight rules flight plan. Visual meteorological conditions prevailed at the time of the accident. The flight originated from Kickapoo Downtown Airport, Wichita Falls, Texas, at 1609 and later diverted to SPS.
Landing Gear Failure
During an approach for landing, the landing gear selection handle was placed into the gear down position. Immediately, the flight instructor and the student pilot noticed electrical smoke and fumes, but no fire occurred. They switched the battery and alternator switches to off to vent the cockpit. After restoring electrical power, they observed that the landing gear up and down position indicator lights were not illuminated, and the landing gear circuit breaker was tripped. They were unable to fully extend the landing gear. The manual landing gear crank handle did not engage and spun freely in both directions, preventing manual extension.
Post-Accident Findings
Post-accident examination by the Federal Aviation Administration of the main landing gear retraction actuator assembly revealed a broken snap ring within the manual crank extension housing. This break allowed the actuator worm gear to reposition itself beyond the actuator worm sector travel limits. According to maintenance records, the airplane had a total time of 6,184.5 hours, and no record showed that the landing gear actuator assembly had been repaired or overhauled. The Baron 55 and 58 Maintenance Manual, section 5-10-00-601 (dated April 1, 2015), specifies that the landing gear actuator assembly is to be overhauled or replaced every 2,000 hours for gray or green colored assemblies. The examined assembly was green colored.