What happened
On 22 May 2016, a Maverick 430, registration G-MZJJ, was conducting a private flight from Monewden Airfield in Suffolk to Shoreham Airport. After a flight duration of 1 hour 40 minutes, the pilot prepared for the return leg with an indicated 35 litres of fuel remaining in a 60-litre tank. The pilot had calculated a fuel consumption rate of 11 litres per hour, anticipating a return flight of 1 hour 40 minutes.
During the return journey, the aircraft encountered unexpected weather conditions. While a tailwind was anticipated, the actual wind at 2,000 ft was from 120º at 15 kt, causing the aircraft to drift west of its intended course. This necessitated backtracking to verify the aircraft's position. Additionally, the pilot was denied permission to transit the Southend Airport ATZ, which further extended the flight duration.
As the aircraft approached the Ipswich area, the fuel gauge indicated only 5 litres of fuel remained. Approximately 2 to 3 miles from the destination at Monewden, the engine ceased operation while the pilot was descending to circuit height. The pilot prepared for an engine-off landing in a field at Shop Farm, Clopton. During the maneuver, the main landing gear impacted the edge of a ditch, resulting in severe damage to the landing gear and lower fuselage. There were no injuries to the pilot or the passenger.
The investigation
The investigation examined the fuel management and flight planning of the crew. It was noted that while the pilot planned for 11 litres of consumption per hour, the actual consumption on the outbound leg was approximately 15 litres per hour. The total flight time of 2 hours 45 minutes suggests that the actual fuel burn rate on the return leg was also higher than the pilot's initial estimates.
Following the event, the pilot noted that approximately 2 to 3 litres of fuel remained in the tank. The pilot suggested that the fuel outlet, located at the rear of the tank, may have become uncovered during the descent, leading to fuel starvation. The investigation also reviewed the pilot's decision to continue the flight despite the low fuel readings without accounting for unusable fuel or the impact of unexpected headwinds.