dalek
Since 1941 there have been 20 recorded military air accidents in the vicinity of the Mull; the first being an Armstrong Whitworth Whitley of 502 Sqn in 1941. These have resulted in more than 120 fatalities.
A very experienced Maritime Captain and Instructor, Sqn Ldr D Kinch, who lost a Brother in Law in the Neptune crash on the Mull on 10th October 1956, wrote the following letter to the Daily Telegraph on 13 December 2000:-
" In light winds and high relative humidity, layers of fog and low cloud form adjacent to the Mull to obscure the high ground completely. There are occasions when a relatively calm sea and a grey sky of similar hue merge, so that in otherwise good visibility a pilot flying in accordance with Visual Flight Rules may be unaware that he is about to enter a fog/cloud bank."
The Chinook pilots had an advantage over the other unfortunates who crashed on the Mull; they could have slowed to walking pace until clear of the fog.
They did not do that.