Brian,
I had an official towing licence for the yellow peril, in order to tow Wessex helicopters at Tengah ('72-'75) from the 1st line (by the golf club) to Hangar 2 (our 2nd line shed) on the other side of the runway. If you were practiced enough (and I was) you could walk alongside it and then hop on and sit on the engine being careful not to drop the steering arm or the brakes would apply. It was a fair old walk across the runway, but if the tower spotted you sitting on the "donkey" then according to them you were not in full control and an interview with the WO man awaited you on return. As the Wessex was a "taildragger" you could get a really serious turning circle with a "donkey" and that was required to park them in our strange 3 sided big "tent" that passed for 1st line repairs storage. Ah the days..........