Stirlingshire microlight crash caused by extreme turbulence
A microlight aircraft crash in Stirlingshire was caused by severe turbulence, an Air Accidents Investigation Branch report has said.
Pilot David Martin, 61, and his passenger Alan McCaskie, 63, died when the aircraft went down close to the summit of Ben More, near Crianlarich.
The AAIB released photographs taken from the aircraft before the crash, which happened on 12 May.
Six snapshots show the snow-capped mountain looming larger and larger.
Mr Martin, from Kinghorn in Fife, had been flying for 12 years and was a member of the Scottish Aero Club in Perthshire
His passenger Alan McCaskie, from Broughty Ferry in Dundee, who was the aircraft's owner, had joined the club in 2011 and was working towards his pilot's licence.
The AAIB said: "The severity of the turbulence created by the wind, close to the summit of Ben More, was such that it exceeded the safe conditions for flight in the microlight.
"This resulted in a loss of control which led to the impact close to the summit of the mountain."
The photos were taken from a video camera attached to the Pegasus Quik microlight.
The report said the video showed the flight path had been stable up to a point about 300m from the summit.
It said: "At this point the aircraft started to roll rapidly from left to right and pitched nose-down".
The AAIB added that the increase in engine power "suggests the pilot was trying to arrest his rate of descent and climb out of the turbulence".
A witness on the top of Ben More saw the last moments of the aircraft's flight and had described the wind at the summit as "very strong".
The report said when the witness removed an item of clothing from his rucksack it was nearly "ripped" out of his hand by the wind.
The AAIB said the microlight's video recordings showed that there was "no compelling visual evidence of the wind speed and direction at the summit".
It added: "It is likely that, in this case, a lack of awareness of the wind conditions, and of the likelihood and severity of turbulence downwind of high ground were factors in this accident."