Accident Overview
On 20 February 2000, at 1250 hours UTC, a Yakovlev Yak-50 (registration G-BWYK) was being prepared for a private flight at North Weald Airfield, Essex. The sole occupant, a 38-year-old pilot with 9,000 total flying hours (30 on type), sustained serious injuries when the engine fired during hand starting.
Pre-flight Actions
The pilot had prepared the aircraft for start-up before taxiing to refuel. He manually pulled the propeller through nine blades to check for hydraulic lock, then returned to the cockpit and primed the cylinders with fuel to assist starting. He had set the parking brake but did not check the position of the magneto switch.
The Incident
As the pilot pulled the propeller through compression to 'suck in', the engine fired. He believed he was first struck a glancing blow to his right elbow, knocking him off his feet, and then struck again on the upper right thigh, throwing him to the ground. His injuries included a severe open wound, broken femur, and slight abrasions to the head. He called for help using his mobile phone, applied a tourniquet to his leg, and waited for assistance. When help arrived, it was confirmed that the magnetos were on.
Aircraft Information
The Yakovlev Yak-50 (and Yak-52) is not fitted with an idle cut-off mixture control. The normal operating procedure to stop the engine is by turning off the magnetos.
Pilot's Assessment
The pilot considered that, despite many years of experience hand starting aircraft, on this occasion he omitted to check that the magnetos were off before moving the propeller.
Injuries and Damage
The pilot suffered serious injuries. No damage occurred to the aircraft.