Update on the cause
When the initial report is an accident happened because "the engine lost power" I'm always interested in exactly what caused the engine failure. From AAIB Bulletin: 3/2016 G-BRRA:
The aircraft took off from Runway 29 at Biggin Hill Airport. The pilot retracted the landing gear and reduced power to 2,400 rpm and +4 boost but, one or two seconds later, he heard the engine ‘cough’. This caused him some concern, so he turned the aircraft back towards the airfield, intending to climb overhead to investigate before proceeding en-route. A few seconds later, the engine lost power and the pilot could see flames coming from the right-hand exhaust pipes....
A limited examination of the engine after the accident suggested that a cylinder in the right bank had a broken inlet valve spring with a penetration of the associated induction flame trap.