There's more.
The civvy owned WW that was used for the filming came from Ireland, and when taking off from Chiv for the filming sequence, developed an hydraulic problem, which caused a vast amount of 'smoke in the cockpit'. The pilot 'panned' back to the dispersal at Chiv, and the SAR GE's changed (I think) an hydraulic pump that had had given up the ghost.
The spare part (don't quote me!) to fix it, may well have been from old RAF stock in the hangar.