Braking device on a vehicle

Claim 1

A HELICOPTER INCLUDING A NORMAL UNDERCARRIAGE FOR SUPPORTING IT FROM THE GROUND, AND AN ADDITIONAL UNDERCARRIAGE COMPRISING A NUMBER OF OPEN SIDED HOLLOW CASES, EACH INDIVIDUALLY SUPPORTED FROM THE HELICOPTER THROUGH A UNIVERSAL JOINT, THE OPEN SIDES OF THE CASE BEING JUST CLOSED BY THE GROUND WHEN THE HELICOPTER IS STANDING ON THE GROUND ON ITS NORMAL UNDERCARRIAGE, A CONNECTION FROM EACH CASE, MEANS IN THE HELICOPTER SELECTIVELY OPERABLE FOR EVACUATING THE INTERIOR OF EACH CASE AND FOR SUPPLYING AIR SUBSTANTIALLY ABOVE ATMOSPHERIC PRESSURE THEREINTO, QUICK RELEASE VALVES ENABLING THE PRESSURE WITHIN THE CASES TO BE RAPIDLY RELEASED, DEFORMABLE WALLS ON THE CASES ENABLING THE VOLUMES OF THE CASES TO BE REDUCED WHEN THE INTERIORS ARE EVACUATED, FRICTION MEANS IN THE OPEN SIDES OF THE CASES FOR REDUCING ANY TENDENCY OF THE CASES TO SLIDE OVER A SURFACE WITH WHICH THEY ARE IN CONTACT, AND A WINCH AND CABLE CONNECTION BETWEEN THE HELICOPTER AND ONE OF THE CASES ENABLING THE CASE TO BE LOWERED FROM AND RAISED TOWARDS THE HELICOPTER AND RELEASABLE MEANS IN THE CONNECTION FROM THAT CASE TO THE HELICOPTER.