Accident Overview
After takeoff from Shoreham-by-Sea Airport's runway 07 in good weather, the pilot, who was also the aircraft owner, conducted a test flight following an engine change. Witnesses observed intermittent puffs of dark smoke from the right engine during initial climb. At approximately 600 feet above ground level, the aircraft rolled to the right, then inverted and spun to the ground. After a brief pause, it burst into flames and was largely consumed by fire. The sole occupant, the pilot, was killed.
Wreckage Examination
Impact occurred on the sloping side of the west flood bank of the River Adur. The aircraft was oriented 60° nose down, rolled to the right, and yawing to the right at impact. Both engines were rotating, with the left engine developing more power than the right. Examination at the AIB engineering facility revealed the rudder was approximately fully left and the elevator fully up. No pre-crash defects were found in the left engine, but severe corrosion was present in the fuel control boost capsule (Part n° CH 90274) of the right engine.
Engine Test Findings
Tests on an engine test bed showed that a perforated boost capsule could induce power fluctuations and cause the engine to experience a rich cut when the throttle was retarded. Previous incidents with the same aircraft type had reported similar fluctuating boost and rpm after takeoff, later attributed to boost capsule perforation.