What happened
During the approach, while on the base leg of the landing pattern, the captain lowered the landing gear. This action was immediately followed by a loud bang and noticeable shuddering of the aircraft. The flight crew declared an emergency and initiated abnormal procedures.
The crew subsequently performed a forced landing at the destination airport. During the landing sequence, all main landing gear tires blew out. Following the arrival, the crew completed an emergency shutdown and evacuated the aircraft; all occupants were not injured.
The investigation
An examination of the aircraft revealed that the left hand main landing gear retract cylinder support frame had failed due to fatigue. This failure resulted in the breaking of the hydraulic lines attached to the retract cylinder, which caused hydraulic fluid to dump overboard. Additionally, the investigation found that the antiskid system had been deactivated.