I think I responded to you elsewhere on this chap.
There were several survivors when the Whitley crashed. The aircraft broke in half and several airmen in the back escaped although one was fatally injured. can I suggest you check if Jurby or Andreas was the airfield. The book "Rough Landing or Fatal Flight" will give the names of the casualties and "Agents By Moonlight" will tell you about Knowles and setting up special duties.
O-D