When Aerospatial, as it was called then, developed the S330 Puma they had this idea whereas it would be able to conceal itself in a forward location by taxiing into cover. Whirling rotor blades make this quite difficult but if the helicopter could propel itself without the rotor any gap in the trees would do.
So they dreamt up the tracked self propelled undercarriage,
For those that don't know the Puma's system there is a means where one can disconnect No1 engine input from the rotors yet leaving them connected to the No1 alternator and hydraulics. This was the source of energy for the tracked undercarriage.
The procedure would have been: Land and shut down, fold the rotor blades, disengage No1 drive, restart No1 and then taxy the aircraft into its hide. There was a ski on the nosewheel to traverse rough ground.
They never tried to operate it on the aircraft but there was a mobile test rig to assess it. Rumour had it that when it passed the hangar doors on yet another test run somebody would start a stop watch. When the inevitable bang and clouds of smoke materialised in the distance the watch would be stopped; a list of times/names checked and the winner scooped the pool.