What happened
On 28 June 1998, a Piper PA-28-161, registration G-BRRM, was conducting a training check flight when a mechanical failure occurred during the departure phase from Rochester Airport. While the instructor and student pilot were climbing out following two successful landings, they overheard ground personnel notifying air traffic control that an object had detached from a departing aircraft. Shortly thereafter, the crew experienced increasing buffeting and loud banging noises.
Upon realizing the severity of the situation, the instructor assumed control of the aircraft. The crew decided to divert to Biggin Hill Airport, prioritizing its paved runway and superior emergency services over the grass strip at Rochester, while also considering the proximity of built-up areas near Rochester. During the transit, the crew noted that the vibration had lessened, likely because the detached component had finally fallen away from the airframe.
As the aircraft approached Biggin Hill, the student pilot observed that parts of the left main wheel were intermittently visible behind the flap, which was also showing signs of damage and vibration. The instructor performed a flapless approach and, as a precaution, shut off the fuel supply during the flare. The aircraft landed and settled toward the left side, though it remained controllable via the rudder. There were no injuries to the two crew members.
The investigation
Investigators examined the damage to the aircraft, which included a punctured fuselage underside, a buckled and holed left flap, and the loss of the left main wheel and oleo strut. Examination of the remaining landing gear hardware revealed that while the upper half of the torque link remained, the lower half was missing. The pivot bolt hole showed no signs of damage.
Technical analysis determined that the oleo strut had over-extended, causing a seal retention ring within the housing to shear. This allowed the strut to release while the wheel remained temporarily attached to the airframe by the brake hose. The investigation concluded that the pivot bolt had either failed or become loose, leading to its loss during a previous takeoff or shortly thereafter.