ZELL Airliner Launch System Idea

[Cobra]

Hey Guys, What If someone Developed a ZELL System to Launch Airliners in areas where Runways were Short? think it would Work? What Airliner could be used for it? the Idea just came to me now! Thanks for looking.Dan

[PR19_Kit]

One thing to bear in mind, passenger G loadings on take-off!

[upnorth]

Boeing did experiment with a RATO system built into the wing filets of 727s for use in high and hot environments:

http://www.youtube.com/watch?v=G7LErwBNobU


As for ZELL itself and an airliner. I think, realistically, the economic concerns surrounding increased stress related maintenance on airframes subjected to ZELL takeoffs along with, I suspect, much shortened service lives of said aircraft would preclude the adoption of such arrangements to most airlines.

Most airlines that operate from those smaller fields aren't the major carriers with bigger budgets.

Now; from a WHIFF point of view, I'd be inclined to stick ZELL onto the smaller regional jets. Things like:

BAC 1-11
BAE 146
Boeing 737

[Weaver]

One thing to bear in mind, passenger G loadings on take-off!

Not neccessarily an obstacle: after all, they've been talking seriously about sub-orbital passenger craft since the 1960s which would subject their passengers to space-rocket levels of G.

Actually, you don't neccessarily have to use high G. You can use a rocket to accelerate a plane to flying speed at a constant 1.5G (for instance) if you're willing to accept that the burn time will have to be longer. Also, since the aircraft would be in low speed flight for a longer time, you might need an attitude control system (possibly on the rocket?) for positive control.

The real problem is not technical, but conceptual: ZELL only lets you take off without a runway, not land without one, so this would only be useful for flights from a runway-less location to one with a runway: not much scope for return tickets.... The RATO concept is probably more viable: build a STOL airliner then use an integral rocket to get it off the runway at high weights. You could see the nozzle(s) concealed in the middle of a 146's airbrakes: it just opens them a bit when the rocket's running to avoid skin heating.

[PR19_Kit]

The prototype Comet 1 was built with provision for rocket motors mounted between the two Ghosts in each wing root. In rear views you can see the conical fairing between the jet exhausts, but I'm not sure if they ever fitted the motors, let alone flew using them.

I'm not sure about the ZELL idea with a 'slow burn' rocket to minimise G loadings. The aircraft will have a minimum flying speed, at least 100 knots in this day and age, and it has to reach that before it gets to the end of the launch support rails, that's a LOT of acceleration!

[rickshaw]

Boeing did experiment with a RATO system built into the wing filets of 727s for use in high and hot environments:

http://www.youtube.com/watch?v=G7LErwBNobU

I can just imagine the passenger reaction the first time they experience that!  "We're on fire!  We're on fire!"   

[Weaver]

The prototype Comet 1 was built with provision for rocket motors mounted between the two Ghosts in each wing root. In rear views you can see the conical fairing between the jet exhausts, but I'm not sure if they ever fitted the motors, let alone flew using them.

I'm not sure about the ZELL idea with a 'slow burn' rocket to minimise G loadings. The aircraft will have a minimum flying speed, at least 100 knots in this day and age, and it has to reach that before it gets to the end of the launch support rails, that's a LOT of acceleration!

Hence why I suggested a Harrier-style reaction control system to operate until minimum flying speed was reached. Since you wouldn't need the RCS for landing, and since a slow-burning, long running rocket is likely to be longer and thinner than a traditional ZELL booster, you could see the booster becoming a kind of "carrier aircraft" with a long, thin body containing the rocket, recovery 'chutes and the pitch and yaw RCS jets at the nose, with two "wings" that carry the roll RCS jets far enough outboard to be useful. You might even see it with a small turbojet which provides bleed air for the RCS and enough thrust to get the (now empty) boost vehicle back to where it can make a near-precision touchdown.

All this is approaching the condition of the various military VTOL "launch platform" aircraft that were suggested in the 1960s, and that might actually be a better way to to go. The "carrier" is an aircraft (possibly manned) that has a large number of vertical lift engines and enough thrust engines to compenstate for it's own mass. The combination vehicle lifts off vertically then uses both the airliner's and the carrier's thrust engines to accelerate to flying speed. As soon as the airliner can manage on it's own, the two separate and the carrier returns to the launch site for a vertical landing.

Going a highly dubious stage further, you could even see the airliner docking with a carrier to make a vertical landing: just don't ask me to be the public liability insurance underwriter for that one!

[PR19_Kit]

But that's getting waaaay off Cobra's original thing about a ZELL launched airliner though...............

[Weaver]

But that's getting waaaay off Cobra's original thing about a ZELL launched airliner though...............

Yeah, but it's as funny though....

Actually, I'm getting ideas about the Plasticart 1/100th Yak-40 I've got upstairs and those Evil Mushroom lift fans....

[Jschmus]

This is maybe not the most hare-brained scheme I've ever seen suggested for airline use, but I know a lot of people who fly all the time and hate it.  They hate airplanes in general.  Asking a bunch of those people to jump into a rocket-boosted airliner is asking for trouble.