WPR21LA209

The pilot reported that, after he was established on the downwind leg for landing, he verified that each of the airplane’s three landing gear were in the down position through the landing gear indicator on the instrument panel and a visual inspection using a mirror located on the right-wing strut, which allowed him to see the undercarriage. The pilot stated that he verified that the landing gear was in the down position a second time after he turned onto the final approach leg. The pilot stated that his approach to the runway was normal with 20° of wing flaps extended and he could hear the stall warning horn as he felt the landing gear contact the runway. Immediately after the airplane touched down, the pilot felt the airplane sink slowly to the left side. The airplane spun slowly to the left and came to rest. The left horizontal stabilizer and elevator were substantially damaged. A postaccident examination of the landing gear system revealed that the down locks for both of the main landing gear exceeded the manufacturer’s maximum clearance. According to the service facility, the resulting play could have caused the main landing gear down lock to retract after the airplane touched down if the landing gear motor lost pressure while the gear was deployed. Further, according to the manufacturer, in addition to a loss of hydraulic pressure, the landing gear required a ground clearance of about 16 inches for it to retract. This could have occurred if the airplane bounced, but the pilot reported that the touchdown was smooth, and the airplane did not bounce. Additionally, the landing gear motor functioned normally during postaccident testing; therefore, it is unlikely that the system lost hydraulic pressure. The service facility reported that the nose landing gear on this airplane normally becomes fully extended before the main landing gear during deployment and photographs of the accident site revealed that the nose landing gear was still deployed while both main landing gear were retracted. As the postaccident examination and analysis did not reveal any anomalies with the landing gear that could have caused the accident, it is likely that the pilot deployed the landing gear late and did not allow the main landing gear to complete its full range of travel before the airplane touched down. This likely resulted in the main landing gear to collapse.