On April 16, 1984, a Swearingen SA226TC (registration N163MA) operated by Midstate Airlines, Inc. was involved in an aviation accident near Milwaukee, WI. Investigators recorded the probable cause as: the binding of the right main gear door due to a slightly bent aft hinge bolt and a dry, unlubricated bushing, which the hydraulic cylinder could not overcome; the lack of recent inspection and lubrication was attributed to the difficult access of the bushing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 2 related events involving the same aircraft type or operator are linked below.
A gear-up landing occurred when the crew could not extend the right main landing gear. Examination revealed a bent hinge bolt and dry bushing that had not been recently lubricated due to difficult access.
Incident Overview
A gear-up landing was performed after the flight crew was unable to extend the right main landing gear through normal and emergency procedures. The aircraft touched down with the landing gear retracted.
Examination Findings
A post-incident examination of the aircraft disclosed that the right main landing gear door aft hinge bolt was slightly bent and difficult to rotate in its bushing. The bushing and bolt were dry and had not been lubricated recently. The hydraulic cylinder was not capable of supplying enough pressure to overcome the binding door.
Maintenance Context
Investigators determined that the bushing had not recently been inspected or lubricated by maintenance personnel because of its location being difficult to access.
Probable cause
the binding of the right main gear door due to a slightly bent aft hinge bolt and a dry, unlubricated bushing, which the hydraulic cylinder could not overcome; the lack of recent inspection and lubrication was attributed to the difficult access of the bushing.
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…