Jet powered alternative to the V-22

Tovarich

Banned
The British worked out that the maximum jet thrust you can point towards the ground, be it metal, tar or dirt, is around 21,000 pounds. This has to do with both the temperature of the jet efflux and the force against the surface. Beyond that and you start melting or eroding the surface....

So how do those launch-pads Nasa employ for space-launches get re-used? :confused:
They must be capable of taking a lot more than 21000lb of thrust.

Or is it simply that whatever they're made of would be prohibitively expensive?
 
So how do those launch-pads Nasa employ for space-launches get re-used? :confused:
They must be capable of taking a lot more than 21000lb of thrust.

Or is it simply that whatever they're made of would be prohibitively expensive?


IIRC the area directly beneath the launch pad at the cape is a deep pool of water.
 
So how do those launch-pads Nasa employ for space-launches get re-used? :confused:
They must be capable of taking a lot more than 21000lb of thrust.

Or is it simply that whatever they're made of would be prohibitively expensive?

Obviously one can make specialized launch/landing pads for rockets (well, up to a point--try it with a fusion rocket and see where it gets you!)

But the point of VTOL is to be able to take off and land anywhere, without having to prepare the field first.

As many have said, if you are going to have to send in a bunch of civil engineers or Seabees or whatever to prepare the landing site first, might as well just make your standard issue runway for your standard issue airplane.

Note no one has yet tried to make a rocket port for a rocket landing on its jets a la a Heinlein juvenile novel. It's one thing to blast off and leave your launching pad red-hot and smoldering (well, wrapped in steam anyway) and another to come down on that and sit on it. For landings we'd need a whole other order of development! Can probably be done--lots of cold water to flush a steel or titanium mesh with, and everyone waits patiently for the steam to die down. But there is no point.
 
Doesn't the USMC/RN varient of the F-35 have one of those lift fans in it, the ones that are just dead weight after VTOL?

100% correct. It carries allot less fuel than the A and C, and at the moment can barely get itself off the ground with a minimum fuel load and no stores.

While the F-35A/C are a workable propsition, the B is a rediculous attempt to build a better mouse trap. The Pegasus engine is the only (spectacularly) sucessful VTOL system for fixed wing single engine flight. I'll try not to say they should stick with Harriers (ala F-111 :D), but.......
 
yes those lift fans are very death weight, during normal fight...

next to BS Pegasus engine Bristol Siddeley build the BS100 engine
this was supersonic version of Pegasus for HS P.1154
http://en.wikipedia.org/wiki/Bristol_Siddeley_BS100
sadly the P.1154 became victim of British politician
and proof of concept prototype Hawker P.1127, became the Harrier Jet

the 1960s were full of prototypes and proposal for Transport VTOL
Lockheed presendt C-130 Hercules VTOL version
FIAT G.222 (C-27A Spartan) had also unbuild VTOL version
The Ling-Temco-Vought XC-142 even build as prototype for US Military
it almost went in service but problems with cross-linked drive shaft
and Budget cut do Vietnam War stopt the project.
BAe had also a proposal for VTOL Transporter (in join venture with Dornier) but i forgot the name of aircraft :eek:
 
IIRC the area directly beneath the launch pad at the cape is a deep pool of water.

I'm pretty sure it's not, or at least it doesn't have to be. The Redstone, for instance, had a thrust of over 70,000 lbs, and it had nothing more than a concrete pad and a slightly elevated ring for the rocket itself to sit on. The only references to water I've seen at LC39 are for the sound suppression water system, which doesn't have anything to do with reducing temperature but instead (as the name indicates) is supposed to absorb and muffle the intense sound waves emitted by the SRBs to prevent damage to the Shuttle. The flames are directed out along concrete blast trenches.

EDIT: You can very clearly see the Redstone's launch arrangements here. Very obviously not a pool of water underneath!
 

Bearcat

Banned
The F-35B is NOT VTOL. It's STOVL. Short take off, vertical landing. Just like the harriers on the Invincibles.

The -Bs will take more development than the A and C variants, just as the Harriers required a lot of fine tuning to become a viable warbird. But that is just a matter of time, money and will. Now whether the US has the will, with the RN opting for C variants for the QEs, that is open to question.
 
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