I was once tasked as enemy to deliver some "Rock Apes" from Gutersloh to one of the RAF "Clutch" stations, by helicopter. We fooled ATC into thinking we were transiting north/south at low level under their MATZ stub (we spoke to discover if there was any inbound traffic as we were about to go in parallel to the runway). We turned hard right and flew unannounced onto the roof of the Ops bunker, whereupon the Rocks rapidly disembarked the Puma from the hover and we were gone in about five seconds. The defending force had so much cam on top of the machine gun posts that they couldn't turn the guns inwards so we were effectively unopposed.
We discovered later that in the commotion we caused our tame Rocks banged on the door, shouting "We're under attack, let us in!" and someone foolishly did let them in......
Lessons were learned.
We learned that it was very difficult to get them to give us a refuel after having such fun at their expense .....