I'm a high boost turbodiesel fanatic (for cost reasons) but agree completely about choice of turbine for such an edge of envelope application, Nick.
On obscure projects: I thought the
vaccum buoyancy project was interesting, albeit requiring >1m^3 per kg MAUW
. Not convinced about the no fuel claim either, unless he is going nuclear to pump in/out the buoyancy tanks
. I also wonder about the weight of the composite structure required to avoid tank collapse compared to that volume of hydrogen at say 500 mbar
. Still, in theory it could hover and land - albeit much more subject to the whim of the wind than a helicopter. Ever seen a blimp do an airfield beat up?
Edit: $300M development seems a tad high, but i don't know heli project costs. I'm guessing S-92 was a $3Bn development project? What sort of concept development time goes on to kick off this sort of project?
Mart