A glider pilot escaped unscathed after his aircraft caught fire as it came in to land at Parham Airfield.
Smoke and fumes filled the cockpit while flames erupted from the middle of the aircraft as the 55-year-old attempted to complete a routine landing at the Storrington airfield, the Air Accident Investigation Branch has said.
The pilot - unaware the vehicle was alight - immediately got out after noticing the smoke and watched on as firefighters battled the blaze which badly damaging part of the aircraft.
According to a report investigators, published last week, the fire was caused by a Front Electrical Sustainer (FES) lithium polymer battery - used to sustain propulsion while in the sky.
In the report investigators said both the plane manufacturer and FES system manufacturer had implemented a number of safety actions to prevent the incident happening again.
The pilot took off from the airfield just after 10.20am on August 10 last year.
Investigators said he had fully charged both FES batteries six days previously and when completing his checks on the morning of the flight there were no faults indicated on the unit which controlled the batteries.
Following take off he flew for nearly 40 minutes before encountering a rain shower and turned on the FES system.
After four minutes it was turned off again but inspectors said the pilot noticed the propeller did not realign itself correctly against the nose of the glider. However, they added he had experienced this before and did not consider it to be a significant issue.
The pilot flew for another hour and fifteen minutes before he came back in to land. As his plane touched down it made an unexpected noise and a smell of burning and smoke filled the cockpit.
He escaped unscathed before flames came bursting out of the battery compartment.
Fire crews were immediately on the scene and the blaze was extinguished however, the glider’s fuselage battery box and surrounding structure were extensively damaged by the fire.
The report said the fire started due to an ‘electrical arcing event’ in the battery where temperatures exceeded around 1,400°C. It addded the pilot did not recall receiving any warning notices about the blaze and he was unaware his aircraft was alight.
Recommendations were put forward by inspectors to the European Aviation Safety Agency, the sailplane manufactures, and the battery manufacturer to incorporate warning systems to alert pilots of a fire or other hazardous conditions when using FES systems.
The plane manufacturer has since replaced the battery compartment bulkhead and the current fleet of FES batteries have been withdrawn and are being ‘refurbished’, the report added.