History of the Flight
On 5 July 1998, a Piper PA-28R-180 (registration G-AVWU) departed Wycombe Air Park, Buckinghamshire, for Le Touquet. Shortly after takeoff, the pilot selected the landing gear up but it failed to retract. He recycled the gear selector and yawed the aircraft, but could not obtain an up or down-and-locked indication. He then used the emergency landing gear selector override in an attempt to extend the gear, but could not achieve three green lights. The pilot performed a low pass over the control tower, where personnel reported the gear appeared to be down. After another circuit, he landed on Runway 25. During the ground roll, the left main landing gear collapsed. The pilot maintained directional control until the left wing dropped, causing the aircraft to swing 90 degrees left and come to rest on grass. There was no propeller strike or fire. The two occupants exited unaided as the fire vehicle arrived.
Landing Gear System Description
The aircraft was equipped with a retractable tricycle landing gear powered by an electrically driven reversible pump, controlled by a selector switch on the left side of the control quadrant. A pressure-sensing device could lower the gear regardless of selector position, based on airspeed and engine power (propeller slipstream). The emergency landing gear lever, located between the front seats, could be used to manually release hydraulic pressure for free-fall extension (with spring assistance on the nose gear) or to override the automatic system. A lock pin on the left side of the emergency lever/flap handle cover could retain the lever in the override position. A placard near the lever stated: "Override engaged / Auto - Ext - Off / Lock pin on side / To engage override: Pull lever full up, push lock pin / To release override: Pull lever full up and release."
Examination of the Aircraft
After recovery, the landing gear system was examined. The electrically powered reversible pump motor was contaminated with hydraulic fluid from a leaking seal, which had been present for some time. This contamination caused the motor to fail, explaining why the gear initially would not retract and later would not extend using the normal system. Selecting the override position still required the pump to function, so the gear could not be lowered. When the aircraft was later moved to a maintenance facility, the emergency down selection (free-fall) was checked and the gear achieved the down-and-locked condition. The placard was a typed paper label that had become soiled and curled at the edges, making it difficult to read from the pilot's seated position.
The aircraft sustained damage to the left flap, left main landing gear, and left wing.