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"KUNG-FU TERRORISTS TO TARGET WEMBLEY"

What the hell? You are afraid that a few terrorists with kung fu powers can overpower hundreds of passengers on a plane. You coward.

We hijack planes and they are then converted into bombs that can be dropped on to crowds packed into football stadiums, or rammed into skyscrapers during prime-time, killing a quarter of a million in a quarter of an hour.

There is no way even a mass hijacking will kill quarter of a million. The article says, talking of a reinforced door that "the cabin crew removed it from its hinges", but when we look at the original articles it's pretty clear that there were crew on both sides and so the door was removed from the cockpit side (where the screws are). What you are spreading is pro-terrorist bluster propaganda; giving the terrorists the oxygen of publicity they need; if we were in a war (and we are not) then you and the daily express should be treated as the Quislings you are. Refuse to be frightened. Refuse to be afraid.

Good stuff. I still think this whole thing is proposterous, but I enjoy the analysis of whether it's even possible, so I postulate the following:

What if instead of rotating wings, the platform was a fixed wing design with a wingspan tremendous enough to:

1) Remain in aloft in a sationary position in the lowest wind speed recorded for the location
2) Reduce the cable length back to 6 miles so that the cable can go straight down instead of in a curved slope

It seems to me that with a sufficiently planned design, the lift created over the stationary wings could easily sustain the 50-100ton hanging load. According to this page, the maximum takeoff weight of a Boeing 747 is 800,000lbs, or 400 tons. If those wings can put that 400 ton aircraft into the sky at 250 MPH, then a similarly sized wing should sustain 50-100 tons in a quarter of that wind speed which is about in line with what you're going to going to expect from the jet stream.

So let's say hypothetically, you have this huge aircraft-sized behemoth "glider" holding its own tether mass with no/few moving parts. Now all we would need to do is outfit the puppy with, say, fore and aft rotors and a central generator to extract power from the same airflow that keeps her afloat.

I'm no expert on fluid dynamics, but it seems at least plausible to me, and potentially more achievable than that helicopter scheme. Plus if there is a problem with the glider version, it could potentially release itself from its tether and land as a normal glider-type aircraft in an appropriately located air strip.

Further, the thing might be launched into position from the very same air strip potentially under battery power using its own generator/props as motor propulsion and carrying its own spooled tether up into the sky with it, lowering the tether for ground connection once it is in position. With a sufficient design it might not even need batteries, and could just remain tethered during flight, spiraling its way upward and carying the tether up with it, drawing power off the grid through the tether itself for motive power, and returning to a state of power generation once in place.

Just exploring ideas... all in all, as I mentioned, I think stationary concepts are going to be more reliable and oceanic deployments definitely solve the "land grab" issues that these wizards were attempting to address by reaching for the sky.

...you get two hundred plus soon-to-be-dead people....

Or, with the new Airbus A-380, well in excess of 800 http://www.aircraft-info.net/aircraft/jet_aircraft /airbus/A380/.

Have a nice flight.

Does this do anything for innovation? The new Airbus A380 is the largest passenger airliner in existence.

Air Foyle HeavyLift does charter that single flying AN-225 that is considered "the world's largest aircraft". (specifications)

It is one thing for a 747 to carry an empty shuttle, and quite another for it to carry one with enough rocket fuel to get from FL100 to orbit, plus its payload and crew.

The takeoff mass of the shuttle is about 2,000 metric tonnes, and the landing mass is only 100 tonnes. (Source: wikipedia). That's a big difference! 1900 tonnes, or 95% of the mass is burnt or otherwise used in getting up there. This is pretty typical of orbital systems: the higher you want to go, the more of your mass you need to burn to get there, and therefore the larger the system needs to be to carry a useful payload. Starting above sea level would help, but you'd still need hundreds of tonnes of fuel.

The shuttle currently needs the external fuel tank and rocket boosters, which are not transported on the 747 and would get in the way of mounting it. Maybe you could do without the boosters if you started from FL100. But I think the shuttle doesn't have much onboard fuel, so you still need the big tank.

The maximum payload of a 747-400 is only 150 tonnes, and that's a more modern plane than the 747-100 currently used as a shuttle carrier. That number is calculated without the extra drag of a whole other aircraft sitting on the back, so I think carrying even an empty shuttle must be close to the limit. Carrying one with even half the required fuel would be impractical. Even if you put the shuttle on a superjumbo, the amount of fuel to drag a shuttle up to launch altitude would be enormous.

While a 747 may be able to fly inverted I don't know if it would be able to do so with a shuttle strapped on the back. Could the shuttle detach and roll upright, while fully loaded with fuel? It's not designed to be the most manueverable aircraft, even when empty. I would suspect it would drop like a stone when fully fuelled.

I think the reason the SpaceShipOne is feasible is that it's a much smaller craft and they don't go all the way to orbit.