Herne Bay air show crash pilot 'trapped by wrong lifejacket'
An air show pilot forced to ditch his plane in the sea got wedged in the cockpit as he was wearing the wrong sort of lifejacket, investigators said.
The plane lost power and crashed when a balloon fragment lodged in the engine during a display, the Air Accident Investigation Branch (AAIB) said.
It was ditched in shallow water off Herne Bay on 14 August 2016.
The pilot, who became trapped by his lifejacket in the cockpit, was rescued from the sea by members of the public.
During the display a series of balloons were released from a boat for the pilot, who escaped with minor injuries, to burst with his propeller at a height of about 500ft (150m).
A fragment from one of the balloons became lodged in the air path of the engine's carburettor and the plane lost power, the AAIB said.
The pilot responded by trying to ditch the aircraft just off the beach, attempting to stall it and land tail-first.
But the main wheels touched the water first, pitching the aircraft forward before it landed upside down in the water, the report noted.
The pilot's lifejacket, a type usually worn by sailors, was designed to inflate as soon as it came into contact with the water.
Members of the public ran into the sea to right the upturned aircraft and helped the pilot out, after he had been submerged for about 20 seconds.
"Although the pilot was able to unfasten his straps, he found himself trapped in the cockpit, with his head close to the sea bed and insufficient space to manoeuvre himself out," the AAIB reported.
"Moreover, his automatic lifejacket had inflated and its bulk and buoyancy were pressing him up into the inverted cockpit."
They described the type of lifejacket as "totally unsuitable for general aviation use", saying they can "seriously hinder escape".
The AAIB has published a safety leaflet giving pilots advice on the use of suitable lifejackets.
The operators of the aircraft have since developed a modification to the plane's engine to allow an alternative air supply in the case of blockage.