Cessna P210 N731LT accident near Atlanta, Georgia

Probable cause

The pilot's delayed extension of the landing gear and his failure to ensure that the main landing gear (MLG) were down and locked before touchdown, which resulted in the collapse of both MLG. Contributing to the landing gear collapse was the mis-set landing gear warning horn, which prevented timely notification that the landing gear were not down and locked.

NTSB analysis

The private pilot reported that he was conducting an instrument flight rules cross-country flight and set up for an RNAV approach; however, he was subsequently cleared for an instrument landing system approach. He added that he continued to the airport, recalled lowering the landing gear, but because he was setting up for a different approach, he did not verify that the landing gear were down and locked. He added that the landing was normal but that, during the landing roll, he heard a "snap" and felt the airplane drop and veer left. The airplane departed the left side of the runway and came to rest with the nose landing gear (NLG) down and locked but with both main landing gear (MLG) collapsed.

Postaccident examination revealed no damage to either MLG downlock hook assembly. Testing of the landing gear system revealed that it functioned normally during multiple gear cycles, including an emergency extension. A check of the landing gear warning horn revealed that it was mis-set about 0.3 inch higher than specified, which reduced timely warning that the gear were not down and locked.

Given there was no damage to either MLG downlock hook assembly, it is likely that neither MLG were down and locked at touchdown because the pilot extended the landing gear late during the approach and did not verify that they were down and locked, which only allowed sufficient time for the NLG, which extends and locks first, to fully extend and lock before touchdown. If the landing gear warning horn had been properly set, it is likely the pilot would have been warned in time to either go around or to allow for complete gear extension before landing.

Text from the NTSB. Open the NTSB docket for ERA16LA042 for the full record.