What happened
On 2 May 2017, a Vans RV-4, registration G-RVER, was involved in a serious incident at Bute Airfield in South LanKShire. Following a period of being parked, the pilot performed standard pre-flight procedures and initiated the engine start-up. During the start-up sequence, the pilot maintained the control column in a fully aft position, which is standard procedure for this aircraft type.
To begin taxiing, the pilot applied power while using right rudder and braking to initiate a turn. During this maneuver, the tail of the aircraft rose unexpectedly. Despite the pilot releasing the right brake, the tail continued to lift until the propeller made contact with the ground. The impact caused the engine to stop after roughly four to five revolutions. Following the event, the pilot noted that a 12-knot wind had developed from the east, creating a tailwind component during the taxi.
The investigation
An examination of the aircraft following the incident revealed physical damage to the propulsion system and landing gear. Specifically, the outer four inches of both propeller blades sustained damage. Furthermore, the investigation established that the engine had undergone a shock-load. The tailwheel assembly also showed signs of distress, with the tailwheel spring retaining bolt hole becoming elongated and the retaining bolt itself bending.
Findings
- The primary cause of the tail rising was the presence of a 12-knot tailwind during the taxi phase.
- The pilot's decision to hold the control column fully aft, while standard for start-up, was inappropriate for the prevailing wind conditions.
- The incident resulted in no injuries to the pilot, but caused significant damage to the propeller, engine, and tailwheel assembly.