Pilgrim
You could be referring to an incident in 1965. I was serving on 105 Sqn in Aden when detailed for the board of enquiry. When a Beaver suffered an engine failure in the Radfan, the Army pilot carried out a successful force landing in a dried up whaddi bed. A Wessex was dispatched from Khormaksar to recover the undamaged Beaver and lift it to the forward air base at Thumeir. Shortly after picking up the Beaver the Wessex pilot experienced a loss of power and jettisoned it. The board was present when the engineers opened up the (sealed) suspect Wessex engine. Sure enough, there was a fore and aft line of sand damaged compressor blades confirming the reason for the loss of power. RAF/Army harmony was restored and the Wessex pilot cleared of any blame. This web site lists units based in Aden at the time
http://www.britains-smallwars.com/Aden/units.html