What happened
On 15 July 2021, a pilot operating a Lancair IV-P, registration ZU-TR/V, departed Wonderboom Aerodrome (FAWB) in Gauteng for a local flight within the general flying area. The flight was conducted under visual meteorological conditions as a private operation. Upon returning to the aerodrome, the pilot received clearance to land on Runway 29.
While the initial touchdown of the main landing gear was normal, the aircraft's behavior changed immediately as the nose wheel contacted the runway surface. The pilot experienced a sudden veer to the left, and the nose wheel skidded at a 90-degree angle relative to its centered position. The aircraft continued to skid for approximately 50 meters before coming to a halt on the runway. There were no fatalities or injuries during the event.
The investigation
An inspection conducted by an aircraft maintenance organisation revealed that although the nose wheel had extended properly upon landing, the tyre had deflated without the pilot's realization. This deflation caused the tyre to fold sideways, which physically prevented the nose wheel's caste ring from rotating left or right. This mechanical restriction forced the wheel to grind against the runway surface.
Further examination of the tyre components identified two punctures in the inner tube. These punctures were aligned with defects on the outer tyre surface, suggesting that an object had pierced the tyre and then exited, leading to a gradual loss of pressure. The force of the skid resulted in substantial damage to the aircraft, including a bent nose wheel trunnion and a cracked engine cradle at the trunnion attachment point.
Findings
- The primary cause of the loss of directional control was a deflated nose wheel during the landing roll.
- A contributing factor was the presence of two punctures in the tyre's inner tube, caused by an object penetrating and exiting the tyre, which led to the gradual deflation of the unit.