Pilot David Martin, 63, and his passenger, Alan McCaskie, 62, died after they hit turbulence while attempting to fly over the summit of the 3850ft-high Ben More in Stirlingshire.
But he lost control in the turbulence created by the mountain, which exceeded the safe conditions for flying the aircraft according to a new report by the Air Accidents Investigation Branch (AAIB)
Accident investigators released the images – taken by a video camera aboard the microlight – which show the final approach before it came down 100ft below the mountain's peak on May 12 last year. The footage forms part of the final AAIB report into the tragedy, which calls for better guidance on mountainside flying.
This is reflected in guidance issued in other countries, including New Zealand, but there is no such advice issued by the Civil Aviation Authority in the UK, the AAIB said. Its report added: "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 report said the video showed the flight path had been stable up to a point about 980ft from the summit.
It added: "At this point the aircraft started to roll rapidly from left to right and pitched nose-down".
The AAIB investigators said the increase in engine power "suggests the pilot was trying to arrest his rate of descent and climb out of the turbulence".
The report said 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.
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 there was "no compelling visual evidence of the wind speed and direction at the summit".
The report 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."