History of the Flight
The pilot, a 59-year-old ATPL holder with 19,840 hours total (175 on type), planned a private flight from Wycombe Air Park to the Isle of Wight and return, expecting a duration of about 1 hour 20 minutes. During initial checks, the left fuel gauge indicated approximately 17 US gallons (64.6 litres) and the right gauge between ¾ and full (67 to 90 litres). A visual check confirmed the left tank was at the tab indicator; the right tank was very slightly below the tab. The technical log showed 97 litres total; the Pilot's Operating Handbook states usable capacity is 180 litres (90 litres per tank).
The engine was started using the right tank, which appeared to have less fuel. A defective headset caused a delay for replacement. For takeoff and departure, the left tank was selected per checklist. The aircraft departed at 1205 UTC. About 10–15 minutes later, abeam Farnborough, the pilot switched to the right tank, intending to use it until the approach. The flight deviated via Lasham to avoid gliders, climbed to 4,000 ft over the Solent, and orbited Hurst Castle. Toward the end of the return leg, the pilot noted a slight left roll tendency; he adjusted rudder trim and checked fuel gauges, both showing roughly 15 US gallons (57 litres).
Just before entering the Wycombe ATZ, a FREDA check showed both tanks indicating about 15 US gallons (57 litres). Flight time was about 1 hour 10 minutes. The pilot joined for Runway 24 and performed downwind checks with similar gauge readings. He elected a touch-and-go for handling practice. The touch-and-go was uneventful; during the climb-out at approximately 100–200 ft after retracting drag flap, the engine rapidly lost power and stopped.
Forced Landing
The pilot lowered the nose, turned left about 60°, and headed for a field. Visual engine failure checks determined no cause. He notified the tower of an engine failure and positioned for landing. At about 100 ft AGL, engine power momentarily returned but then failed again. The power surge allowed a slightly better landing area. Insufficient height remained for further troubleshooting; he closed the throttle and landed in the selected field on a heading of about 070°. During the landing roll, maximum braking was insufficient to stop before the far hedge; rudder and differential braking yawed the aircraft left. It came to a halt at approximately 1320 UTC, about 15–20 m from the hedge, on a heading of about 360°. The time from right tank selection to accident was about 1 hour 15 minutes.
Engineering Examination
A licensed engineer examined the aircraft 30 minutes later. No fuel was visible in the right tank; the left tank showed slightly below the tab (approx 64 litres). No fuel leaks were found from tanks or drain valves. The engine turned freely with no leaks. The fuel, magneto, and battery master switches were off; other electrical services were on. When the battery master was selected on, no fuel pressure was indicated. The left gauge showed approx half full (12 US gallons / 45.6 litres); the right showed about 2 US gallons (7.6 litres). With fuel selected to the right tank and electric pump on, the fuel failed to prime (rapid clicking). On selecting the left tank, the pump primed and pressure indicated 4 psi. The engine started and ran normally on the left tank; a full-power run and magneto/carburettor heat checks were normal. With the right tank selected at 1,500 rpm, fuel pressure dropped to zero after 65 seconds; the engine stopped 15 seconds later and would not restart. Repriming with the left tank restored normal operation.
Before aircraft recovery, 50 litres of Avgas was drained from the left tank and 150 millilitres from the right tank. The Pilot's Operating Handbook states unusable fuel in critical attitudes is 1 US gallon (3.8 litres); the Maintenance Manual gives 0.125 US gallon (0.47 litres) per tank.
Pilot's Assessment
The pilot provided a full account, stating: "The primary cause was my failure to select to the left tank during the FREDA and the downwind checks when returning to the Wycombe airfield." Secondary causes included possible overestimation of right tank quantity, an optimistic right fuel gauge, and increased fuel burn due to long taxi, diversion, climb, and orbit. He estimated 15 minutes endurance remained in the right tank, but the factors reduced it to just a few minutes.