What happened
On 7 March 2000, a Beech D55 Baron, registration G-MOSS, was conducting a private flight from Guernsey to Elstree Aerodrome for the purpose of preparing the aircraft for its Certificate of Airworthiness renewal. While entering the landing circuit at Elstree, the pilot selected the landing gear to the down position. During this process, a physical thump was felt beneath the front right seat, and the cockpit indicators showed that the nose and left main gears were locked, but the right main gear remained indicated as red.
Attempts to rectify the situation through reselection and the use of the emergency selector were unsuccessful, leaving the gear in an unconfirmed state. After performing two flypasts of the control tower to assess the situation, the pilot decided to proceed with the landing. Upon touchdown, the pilot attempted to distribute the aircraft's weight toward the left and nose gears. Although the right main gear initially appeared to support the aircraft, it suddenly collapsed. The pilot immediately cut the fuel mixture and feathered both propellers, bringing the aircraft to a stop with no injuries to the crew. The incident resulted in damage to the right propeller, engine cowl, flap, and aileron.
The investigation
Investigators examined the landing gear mechanism and the aircraft's maintenance history. It was noted that the aircraft had been parked for an extended period in Guernsey prior to being acquired by its new owner. Subsequent inspections by the maintenance company revealed that the up-lock roller on the right main landing gear had seized. As the mechanism attempted to release the up-lock, the gear actuating rod became bent. Because the rod was now effectively too short, the gear could not complete its travel into the down-lock position.
Findings
- The primary cause of the gear failure was a seized right main landing gear up-lock roller.
- The bending of the gear actuating rod prevented the landing gear from reaching the locked position.
- The aircraft had undergone recent maintenance on the landing gear bushes and joints, but these components appeared to have been left unlubricated.
- Prolonged storage in Guernsey had led to corrosion in various articulated joints and bushes, which had necessitated significant repair work prior to the flight.