What happened
On 4 June 2001, a Vickers-Supermarine Spitfire PR.XI, registration G-PRXI, was participating in a private aerial display at the Vallee de Seine Airport near Rouen, France. While flying in a formation of four aircraft, the pilot began to drift from the intended position. The pilot subsequently radioed that there was a problem and intended to return to the airfield, opting to use the grass runway.
As the aircraft approached the runway on a base leg, the pilot noted the presence of people on the airfield. Video evidence captured the moment the aircraft's propeller speed dropped following a burst of power and a puff of black smoke. Immediately following this, the right wing dropped, the aircraft rolled inverted, and entered a vertical dive. The impact resulted in the destruction of the aircraft and the fatal injury of the pilot.
The investigation
The investigation, involving the French BEA and the UK AAIB, focused heavily on the Rolls-Royce Packard Merlin 266 engine. While the engine remained largely intact after the crash, a strip examination conducted with the assistance of the Battle of Britain Memorial Flight revealed significant issues within the ignition system.
Technicians discovered that both Rotax magnetos were not airworthy. The right magneto showed evidence of electrical tracking due to a degraded rubber insulator and oil contamination caused by a missing grease retention plate. The left magneto exhibited poor spark performance and internal corrosion. Furthermore, the investigation found that the high-tension leads used aluminium inserts instead of the required copper, which can cause insulative issues.
Findings
- The primary cause of the power loss was electrical failure within the magneto ignition system.
- The right magneto's rubber insulator was severely degraded and thermally unstable, leading to electrical tracking.
- The left magneto was unable to provide consistent, reliable sparking, contributing to a significant loss of engine power.
- The use of aluminium inserts in the ignition harnesses was identified as an unsuitable practice compared to copper.
- Discrepancies were found in the engine maintenance records, as the serial numbers of the installed magnetos did not match the documentation provided for the engine overhaul.