History of Flight
On May 20, 2018, about 1950 Pacific daylight time, a Piper PA24-250 airplane, N244TW, sustained substantial damage shortly after landing at Norman Y. Mineta San Jose International Airport (SJC), California. The private pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed, and no flight plan was filed. The flight originated from French Valley Airport (F70), Murrieta/Temecula, California, about 1730.
According to the pilot, he had rented the airplane from Plus One Flyers at McClellan-Palomar Airport (CRQ), Carlsbad, California. After an uneventful flight from CRQ to F70 earlier, he departed for SJC. Near the "Pruneyard" VFR reporting point, he contacted SJC tower and was instructed to cross midfield at 2,000 ft, then entered a right downwind for runway 30R. He reduced power, extended the landing gear, and verified a green indicator light. The approach and touchdown were normal. While braking at about 30 mph near the intersection of runway 30R and taxiway Echo, the landing gear "suddenly collapsed." The airplane slid on its belly and stopped about 150 ft beyond taxiway Echo. Airport safety personnel assisted; the airplane was lifted and towed. FAA inspectors noted substantial damage to the fuselage structure.
Aircraft Information
The airplane, manufactured in 1958, was equipped with a Lycoming O-540 series piston engine. It was purchased by its current owners in 2013 and placed on leaseback to Plus One Flyers. The most recent annual inspection was completed on May 18, 2018, at about 2,918 total hours. All applicable FAA airworthiness directives, including AD 77-13-21 for main landing gear bungees, had been complied with.
Landing Gear System
The tricycle landing gear is electrically controlled via a handle on the instrument panel and actuated by a single motor-transmission in the cockpit floor. All three gear are mechanically interlinked and move in unison. Each gear locks in place with an overcenter link assembly. Microswitches on each gear close upon full extension; all three must close to illuminate the green light and stop the extension motor.
Wreckage and Impact Information
After the accident, the airplane rested upright with all gear nearly fully retracted. The cockpit landing gear handle was in the DOWN position. When lifted, the gear partially extended. Manual manipulation of the nose landing gear (NLG) forward caused both main landing gear (MLG) to fully extend and lock. The emergency extension system was intact. Visual inspection of wheel wells and linkage showed no obvious failures. The right MLG tire had scuff marks.
Tests and Examination
When the airplane was raised on jacks and powered, the gear retracted normally. However, extension via the normal system was only partly successful: the gear extended but the motor continued running and the green light did not illuminate. Manual attempts to fully extend the NLG were unsuccessful. The MLG overcenter stops were observed in contact, but the NLG drag link overcenter stops were not contacting, indicating incomplete NLG extension. The NLG microswitch was not closed. Proper rigging requires all three overcenter stops to lock. The reason for the improper rigging could not be determined; no damaged or worn components were found.
After recovery, the airplane was transported to an off-airport facility. During disconnection for transport, the MLG push-pull cables and motor/transmission were separated. All three gear could then be fully extended with proper stop contact. The NLG overcenter stops now closed, indicating that the NLG had been not fully extended previously. Examination of the motor and transmission revealed no damage or wear. The investigation was unable to determine the specific reason that prevented the NLG from fully extending before separation from the rest of the landing gear system.