On August 29, 1982, a Cessna 310C (registration N1737H) operated by Alvin E. Potter was involved in an aviation accident near Brunswick, GA. Investigators recorded the probable cause as: Improper adjustment of the landing gear downlocks, which permitted the gear to unlock during landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot reported an in-flight electrical failure after takeoff, requiring a hand-cranked gear extension. The left main gear collapsed upon landing due to improperly adjusted downlocks.
What happened
The pilot reported experiencing an electrical failure in flight shortly after takeoff. In response to the malfunction, he manually cranked the landing gear into the down and locked position before commencing the landing approach. Upon touchdown, the aircraft rolled approximately 200 feet before the left main gear collapsed.
The investigation
A subsequent examination of the landing gear mechanism revealed that the landing gear downlocks were out of adjustment. Specifically, the downlocks could be opened with mere finger pressure. Standard maintenance procedures require normal tension on the downlocks to be between 40 and 60 pounds.
Findings
The investigation determined that the primary factor was the improper adjustment of the landing gear downlocks. This maintenance error allowed the gear to unlock under load, leading to the collapse upon impact with the runway surface.
Probable cause
Improper adjustment of the landing gear downlocks, which permitted the gear to unlock during landing.