On March 15, 1984, a Cessna 401 (registration N777CS) was involved in an aviation accident near Chicago, IL. Investigators recorded the probable cause as: The shearing of the bolt on the top portion of the left-hand bellcrank assembly and the breakage of one of the tangs at the bottom of the bellcrank, which exhibited instantaneous overload characteristics. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
The left main landing gear collapsed during the landing roll after investigation revealed a sheared bolt on the bellcrank assembly exhibiting instantaneous overload characteristics.
What happened
During the landing roll, the aircraft's left main landing gear collapsed. The incident occurred while the aircraft was moving along the runway surface following touchdown.
The investigation
Examination of the landing gear components revealed that the bolt located on the top portion of the left-hand bellcrank assembly had been sheared off. Additionally, one of the tangs at the bottom of the bellcrank was found to be broken.
When the fractured surfaces were examined under a 10-power microscope, the fracture characteristics indicated instantaneous overload.
Probable cause
The shearing of the bolt on the top portion of the left-hand bellcrank assembly and the breakage of one of the tangs at the bottom of the bellcrank, which exhibited instantaneous overload characteristics.
A SkyWalk Join't 3 paraglider crashed into the ground near Las Vizcachas, Chile, on September 1, 2024. The pilot and passenger sustained serious spinal…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2024-09-01DGAC Chile
A Cessna 172N struck electrical cables while on final approach to land at Aucó Aerodrome in Chile. The pilot was uninjured, but the aircraft sustained damage…
A Bombardier DHC-8-402 suffered a tail strike during landing at Puerto Williams on September 9, 2024. All 76 occupants were unharmed, but the aircraft…
A MYD JS-MD 3 glider veered off the runway and struck a wall at Vitacura Aerodrome on January 6, 2025. The pilot was uninjured, but the aircraft sustained…
A recreational paraglider flight in Puchuncaví, Chile, ended with the pilot sustaining serious injuries after a rapid descent and impact with a hillside on…
PARAPENTE (ULTRALIVIANO NO MOTORIZADO)·2025-03-29DGAC Chile
A Tecnam P2006T landed on its belly at an aerodrome in Poland after the crew failed to confirm landing gear deployment. The incident resulted in no injuries…