Jump to Content

Summary

Summary

During approach, the crew of the Boeing 737 selected "gear down". A loud "bang" was heard and the "gear safe" green light for the right main landing gear illuminated immediately. The left main and nose landing gear lights illuminated in a time consistent with a normal extension sequence. As the cockpit indications showed that the landing gear was locked down, the approach was continued and a normal landing was completed.

History of the flight

During approach, the crew of the Boeing 737 selected "gear down". A loud "bang" was heard and the "gear safe" green light for the right main landing gear illuminated immediately. The left main and nose landing gear lights illuminated in a time consistent with a normal extension sequence. As the cockpit indications showed that the landing gear was locked down, the approach was continued and a normal landing was completed.

Inspection of the aircraft revealed that the right main landing gear (MLG) trunnion pin attach lugs had failed. As a result, the right main gear hydraulic actuator disconnected from the MLG assembly, resulting in free-fall of the right MLG during extension to the "down and locked" position. The trunnion pin failure resulted in little damage to the actuator and surrounding structure. No damage to control cables or hydraulic lines occurred.

Diagrams of the B737 landing gear assembly and photographs of the damaged trunnion pin are available on the ATSB website linked to this occurrence number.

 
Share this page Comment