CEN14LA107

The pilot reported that he lowered the landing gear and observed gear-down indications before touchdown; however, the landing gear collapsed during the landing. A postaccident examination of the airplane revealed that all three landing gear had collapsed; no anomalies in the extension/retraction linkage were found. The airplane owner reported that, during recovery of the airplane, he had adjusted the nose landing gear actuating rod for the nose gear to fully seat on the stop flats. Additionally, the landing gear had been serviced during the most recent annual inspection, which was about 24 flight hours before the accident. Although it is possible that the landing gear was not properly adjusted after the maintenance work, several flights had been conducted in the interim without any reported issues related to the landing gear system. Postaccident examinations revealed that the nose landing gear down lock switch was improperly mounted upside down and that the limit switch was stuck in the closed position. The inoperative nose landing gear switch would have provided a gear down/locked indication to the pilot regardless of the nose landing gear condition. It is possible that the nose landing gear did not fully extend and lock down before landing due to either the inoperative limit switch or a slight misrigging of the system. However, because the landing gear was operated by the transmission jackscrew, it is unlikely that an issue with the nose landing gear would have caused a collapse of the main landing gear if the main landing gear was fully extended and locked in the down position. The reason for the landing gear collapse could not be determined.

On January 3, 2014, about 1515 mountain standard time, a Piper PA-24-250, N6767P, sustained substantial damage when the landing gear collapsed during landing at the Grant County Airport (SVC), Silver City, New Mexico. The pilot was not injured. The aircraft was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight originated from the Deming Municipal Airport (DMN), Deming, New Mexico, about 1430. The pilot reported that he lowered the landing gear on downwind and observed a gear down indication before touchdown. He noted that the approach was normal; however, the landing gear collapsed during the landing rollout.A postaccident examination was conducted by a Federal Aviation Administration (FAA) inspector after recovery of the airplane. All three landing gear had collapsed. Damage included bent and buckled fuselage frames. The examination did not reveal any anomalies in the extension/retraction linkage. However, it was noted that the nose landing gear down lock switch was improperly mounted upside-down and was not making contact with the striker plate. Further examination revealed that the limit switch plunger was stuck in the closed position. The airplane owner informed the assigned FAA inspector that after the accident, he adjusted the nose landing gear actuating rod in order for the nose landing gear to fully seat on the stop flats. A mechanic noted that there may have been damage to one of the frames, causing the nose landing gear to become out of rig. However, the FAA inspector reported that there appeared to be no movement of the landing gear transmission mounting at the time of the postaccident examination. Maintenance records indicated that the landing gear had been serviced during the most recent annual inspection. This included repair of the gear motor transmission, a rebuild of all three landing gear struts, and replacement of the bungee cords. The maintenance work and inspection was completed on April 11, 2013, at a recording tachometer time of 2,862 hours. The tachometer indicated 2,886 hours at the time of the accident. The landing gear retraction mechanism included push-pull cables to each main gear and a push-pull tube to the nose gear. The transmission motor installed below the cabin floor drove the transmission screw (jackscrew), which in turn actuated the push-pull cables and push-pull tube to extend or retract the landing gear. Limit switches installed on each gear assembly would stop the transmission motor when the landing gear was fully extended or retracted. These switches also operated indicator lights in the cabin. A safety switch was located on the left main gear assembly in order to prevent the gear from retracting while the airplane was on the ground.