What happened
On December 27, 2005, at approximately 13:55 UTC, a Beechcraft BE76, registration CS-AVL, was performing a flight training mission departing from Covilhã Aerodrome for Tires Aerodrome. The aircraft was occupied by an instructor and two student pilots.
During the takeoff roll, as the aircraft approached $V_1$, the crew heard a loud burst. Because the aircraft had already surpassed the decision speed, the instructor took control and elected to continue the takeoff to avoid a runway excursion. After completing a circuit, the crew returned to the same runway to land. The approach was conducted at minimum $V_{Ref}$ with full flaps to mitigate potential damage. Upon landing and subsequent inspection, it was confirmed that the right main gear tire had burst and the rim had sustained damage due to contact with the runway surface.
The investigation
The GPIAAF examined the aircraft' and the tire remnants. Analysis of the tire tread revealed characteristic faceting and erosion patterns typical of a locked wheel dragging on an abrasive concrete surface. The investigation established that the tire had been structurally weakened during a previous landing at the same aerodrome. During that prior arrival, a student pilot performed a hard landing on the right main gear, likely with the brake applied, which caused the initial damage. This damage remained undetected during the pre-flight inspection because the affected area was in contact with the ground.
Findings
- The primary cause of the tire burst was poor landing technique during a preceding flight, which caused abnormal wear to the tire structure.
- The instructor's pre-flight inspection was insufficient to detect the hidden damage on the tire tread.
- The crew's emergency management was noted as non-standard, specifically the decision to retract the landing gear after the initial burst before returning for the landing.
- There were no injuries to the three occupants, though the aircraft sustained damage to the right tire and rim.