Modern jets scaled versions

[ZENTA]

Hi all,

Is there any particular reason why people do not design scale down versions of modern jet fighters (F-16, F-18, etc.)?

I'm sure I am not the only one dreaming of my own small version F-18 Super Hornet.

Thanks in advance for your input.

 

[GregLocock]

Of course there is.


Do you mean an absolute scale model? that would still fly? and carry a pilot?

It would cost hundreds of millions to develop and crertify, and millions to build, and a lot of training to fly.

Or do you mean something less ambitious?







Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[ZENTA]

Thanks Greg for your reply,

I was thinking along the lines of a long-ez in terms of construction and configuration. Maybe twin wankels on the back driving counter-rotating props on a single shaft to keep the profile of the design(except for the props).

Of course I do not know how the aerodynamics, cg, etc would play out, but I am sure it can be worked out.

It is just a thought that came to me while watching a canard aircraft video.

 

[IRstuff]

You can buy micro-turbine engines for R/C planes, if you want something a little more practical:

http://www.swbturbines.com/swb-35.htm

http://www.asiascalerc.com/links.htm

http://www.skymasterjet.com/22.htm

I haven't actually seen one fly in person, but I've seen the videos and it kicks butt compared to any fan propulsion:

http://www.rcarf.com/f16s.wmv

http://www.airpacmodels.com/skymasterfiles/f-2204.wmv

http://www.airpacmodels.com/skymasterfiles/f22.wmv

Prices are in the low to mid-thousands...

TTFN

 

[ZENTA]

Thanks IRstuff, but I am actually talking about a 50% scale model that can carry at least a pilot, and the use of pusher propellers to minimize cost.

Again it's just a thought.

Cheers,

Eddy
Miami, Fl.

 

[InteroperabilityFix]

I don't know about the F18, but the F16 is fly by wire. You couldn't fly that plane with direct linked controls because it is very unstable.
So scratch the F16.
Say you went and built a scale F4, how would you learn to fly it? You'd have to first train in a swept wing jet trainer like the T38.
What about testing? Would you do it yourself, after having flown say a T38 and maybe gotten some hours, at best, in a privately owned Phantom? Would you get a real F4 driver to test it for you? Would they be crazy enough to try it?

If you want to fly a jet fighter lookalike, this is your best bet:

http://www.viperjet.com/

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[IRstuff]

The kit is only $183K!!!

For another $75K, they'll pre-build parts of it for you.

TTFN

 

[ZENTA]

The motivation for my question was a video of a Rutan Long-ez being modify to install a jet engine, it closely resembled many of today's jet fighters. I proceeded to search the internet for similar projects without any luck, which just made me more curious about it.

I did find however several examples of smaller versions of old fighter aircrafts (P-51, Corsairs, etc).

I also found F/A-18 r/c models using pusher props.

I guess my question should have been, why isn't anybody even trying to design an F/A-18 look alike with pusher propellers?

Cheers,

 

[wes616]

1. market size
2. insurance



Wes C.
------------------------------
Light travels faster than sound. That's why some people appear bright until you hear them speak.

 

[Zapster]

The kit is only $183K!!!

Price sounds cheep if it includes a GE power plant with 0 hours on it. I assume the kit does not include the power plant.

 

[IRstuff]

Yep, sorry, got too excited.

Kit does not include the engine, engine installation kit, avionics, instruments, unholstery, paint, or wiring.

TTFN

 

[swearingen]

The F-18 is fly-by-wire also. The reason all of the more recent jets are is because a human can't fly them at slow speeds. They are so unstable that they require many very fast inputs and our reaction times are not up to par. The flight control computer(s) get information from the pilot's stick and rudder pedals and interpret that information to give the pilot what he/she wants. They are purposely made this unstable at low speed so that they are more maneuverable at high speeds.

Scaling down these aircraft may alleviate some of these problems, but it may also exacerbate others. I'd hate to know that I was flying a shape that is inherently unstable even if it's scaled down...

 

[monkeydog]

Dont forget what makes these planes great fighter planes is the fact they are unstable, thus highly manuverable.

 

[scotty7]

Whilst F16 F18 etc are unstable, this is because of the aft CG leading to a lack of static and dynamic stability. Stick a load of lead in the nose, and it could be flown conventionally - this would have to be a consideration for a small copy. As would wing section etc. Not easy without considerable understanding of the aero.

 

[InteroperabilityFix]

http://www.f22r.com/

there u go

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