Just read the very sad news.
David was my flying instructor at RAF Akrotiri in 2003 during PPL training. He was a very likeable chap and had a huge amount of experience to share.
I saw a video of him line training on a Cathay L1011 and his teaching style was exactly the same as with me on the C172. As a previous poster said - unflappable.
I remember in my infancy of learning to bash the circuit (when 80kts felt like 450 kts

) I asked David to set the power or something like but forgot to say please. He gently chided me with, "..even as a 747 Captain you still have to say please when asking the FO to do things for you.." Never forget that.
I know David was a well thought of member of the village he lived in as well as the Aircrew Association.
It is a real loss and my thoughts are with Diana.
The Cat.