What happened
On 17 April 1999, a Piper PA-28R-180, registration G-WWAL, was completing a private training flight at White Waltham Airfield. As the aircraft was taxiing toward its designated parking position, the pilot heard an unusual noise originating from the left-hand wheel. In response, the pilot brought the aircraft to a stop and shut down the engine.
Upon conducting a visual inspection of the area beneath the port wing, it was discovered that the left main landing gear wheel had struck a metal tie-down stake. The stake had been driven into the ground with approximately 4 inches of the metal protruding above the surface. There were no injuries to the two crew members or the single passenger on board.
The investigation
An examination of the aircraft's structure was conducted following the incident. While the tyre remained inflated and the landing gear strut showed no signs of damage, the impact had significant consequences for the wing structure. Engineering inspections revealed that the port upper wing surface had lost several rivets and the main spar had experienced twisting.
The investigation focused on the visibility of the hazard. It was determined that the metal stake was dark in colour, lacked any identifying markings, and was partially obscured by grass, which prevented the pilot from detecting it during the taxiing maneuver.