Walking/Air Cushion Ambulance Idea

[PR19_Kit]

My point about aerospace tech is that most hovercraft control systems are fairly simple, consisting of just rudders in the propwash. If you had a powerful hovercraft with gas-turbine engines, you could have something like a Harrier's reaction control system, using bleed air to feed variable side and front nozzles which could push the thing around much more precisely. You could also have either a thrust-reverser system or reversable pitch thrust blades (depending on what the craft's thrust mechanism was) to give powerful braking without dumping the cushion.

The larger Westland 'craft had exactly that sort of system, with the rotating prop masts on the roof in the case of the SRN2, 3 and 4 and puffer ports on the  SRN5 & 6. All had reversible pitch props, but certainly the SRN4s took some stopping like that, simply due to the inertia of 300 odd tons.

The puffer ports bled air from the lift fan systems rather than bleed from the compressor stages, possibly because the air was available anyway.

[Weaver]

Cheers Kit - I knew about the rotating prop masts but not about the puffer ports. 

Like you say, the problem with stopping any hovercraft is inertia. You can get them up to impressive speeds, but they are, effectively, aircraft, so they have all the same stopping problems: more actually, since an aircraft has wheels, so once they're on the ground, conventional braking can be applied.

[PR19_Kit]

I suppose 'ports' in this context is taken in a VERY wide sense. On the SRN6 they are about 4-5 FEET square, unlike the Harrier's control jets, which are only inches across. I guess it's a matter of the type of energy involved, the Harrier system using high velocity and high pressure air and the hovercraft the exact opposite.

[Weaver]

Yes, that's just what you'd want on a ground vehicle: high volume, low pressure ducts rather than the Harrier's low volume, high pressure ones. There's no point having a hover ambulance that creates more casualties than it saves by knocking passers-by on their backsides every time the driver moves the stick/wheel....