What happened
On the morning of 10 May 2015, a Yak-52, registration ZU-ULU, departed Vereeniging Airport (FAVV) for Rand Airport (FAGM) under visual flight rules. While the flight itself was completed without incident, a collision occurred upon arrival at Rand Airport.
After landing safely on runway 29, the pilot began taxiing at approximately 15 knots. While attempting a 90-degree left turn on taxiway 17, the aircraft suddenly suffered a loss of both steering and braking capabilities. Due to the downward slope of the taxiway, the aircraft drifted approximately 40 meters off the taxi and struck a parked, unoccupied Piper PA-31 Chieftain, registration ZS-LKM, near hangar 12. The impact caused the propeller of the Yak-52 to strike the right-hand wing tip of the ZS-LKM. There were no injuries to the pilot or the passenger.
The investigation
Investigators examined the mechanical state of the aircraft following the collision. The inspection of the Yak-52 revealed damage to the engine front, the spinner, and the loss of one propeller blade. The parked ZS-LKM sustained damage to its right-hand wing tip, landing gear door, and the fuselage area below the horizontal stabilizer.
Technical analysis focused on the left wheel assembly. Upon disassembly, investigators discovered that the brake drum had been destroyed by corrosion. This specific area of the component is located in a position that is inaccessible during standard annual inspections.