Fatal crash plane 'was overweight', says air accident report
A plane that was involved in a fatal crash on Bute had been fitted with unrecorded modifications which meant it was likely to have been over its maximum weight, a report has found.
The accident happened shortly after the home-built SportCruiser took off from Bute air strip in August of last year.
Thomas McGowan, 63, died in hospital after suffering 80% burns in the crash.
The Air Accidents Investigation Branch said the modifications meant the plane did not comply with its Permit to Fly.
Investigators were told by the pilot, who survived after suffering 40% burns, that the aircraft lost power and could no longer climb as it took off on a return flight to Strathaven, in South Lanarkshire.
Burst into flames
He attempted to return to the runway, but instead flew into the ground.
The plane came to a rest upside down, with witnesses saying it burst into flames almost immediately.
An aviation pathologist said there was no evidence of significant impact injuries, but evidence suggested the temperature in the cockpit had reached between 650C (1,202F) and 1,200C (2,192F).
The pilot managed to escape before pulling out Mr McGowan, from Stonehouse in South Lanarkshire, who died after being airlifted to hospital.
The Air Accidents Investigation Branch (AAIB) report said the plane, with the registration G-EWZZ, had been fitted with a Woodcomp SR 3000/3 variable pitch propeller.
But the propeller had not been recorded in the aircraft's documents, and the 53-year-old pilot did not appear to have been trained in its use.
The AAIB said the single-engine aircraft had also been fitted with an autopilot, which again had not been recorded.
With these two modifications, it was likely that the plane had been over its maximum take-off weight (MTOW) of 1,323lb (600kg), the report stated.
The report said: "G-EWZZ was a home-built aircraft that had been fitted with unrecorded modifications, which meant that it was not in compliance with its Permit to Fly.
"Calculations show that with these modifications the aircraft was likely to have been over its approved MTOW of 600kg when it departed Bute.
"The pilot reported that the aircraft flew satisfactorily on the outbound flight to Bute and that it was during the climb from the airstrip on the return flight to Strathaven that he experienced the symptoms that caused him to believe that he had a partial loss of engine power.
"The lack of performance could have been due to a combination of factors including a technical fault, handling and aircraft weight."
However, investigators said although the aircraft was probably overweight, it is unlikely that this alone affected its performance to an extent that it could not have sustained a positive rate of climb.
They also said they did not believe the presence of the autopilot system would have caused the crash.
Video evidence showed that the engine was still running at the end of the flight, and the ground marks and damage to two of the propeller blades were evidence that it was still producing power.
But the damage to the engine and aircraft fuel system meant that it was not possible to establish if the engine had sustained a partial loss of power.
The AAIB also noted that the single-engine plane was fitted with a Ballistic Parachute Recovery System (BPRS) which was not activated during the flight.
It issued seven safety recommendations relating to the system, which deploys a parachute by use of a rocket.
Emergency responders should be made aware of the risks associated with the device, and how to spot and disable it following an accident, investigators said.