Fly by wire has nothing to do with how stable the plane is. Airbus use fly by wire as did concord but the planes are not particularly unstable.
You are confusing making an unstable plane (stealth, F22, etc.) and needing fly by wire to fly it with what fly by wire is, its just a control system designed for a particular purpose.
They typically start on gas (butane/propane) from an external can, & then run on kerosene
Agreed. I as using it in the sense the person who first introduced it to the thread, used it.
Correct
As do quite a lot of stable aircraft, but the one thing they usually have in common is a mechanical back up if their computers fail. Even the true fly by wire and nothing else have a back up to get them home. It's a bit like the engine management in a car. If it goes bits up, there is still the ability to get you home in the software.
Why would a stealth aircraft require fly by wire?
The purpose is to allow a computer to fly the aircraft and nothing else. Let the pilot get on with seducing the air stewardess, ready for the sleepover. ;-) Remember the Trident aircraft, the first to be cleared for take off and landing in fog? That was computer assisted flight.
Dave
It's not because of the stealth. Recent high performance jet fighters are deliberately built to be unstable because it makes them more maneuverable. It's not possible to control them with human reflexes so fly-by-wire is necessary,
That is definitely not my strong point, I have to say, but I think we are going down the same street on this :-)
None of the aircraft I worked on had elevators. Tail planes, tailerons and canards were the norm.
I will, thanks for pointing that out.
Dave
on kerosene
That rings a bell from discussions with my model flying computer guru. Thanks
Dave
Because it is shaped to be stealthy rather than to fly.
A Sopwith Camel is unstable (at least in pitch) and certainly predates electronic controls.
Andy
In message , "dennis@home" writes
Wossat dennis - the right shape to hide behind lamp posts, in doorways and disguised in a fedora and Mac?
talerons are elevators, by another name. as are canards.
Stability is merely a matter of the correct position of the C of G, by and large. Yes, it varies with the shape, but it doesn't vanish entirely ;-)
The reasons for fly by wire are many: Choose from a non exhaustive list..
- the plane is unstable, to gain manoeuvrability.
- the plane is marginally stable to allow most efficient low drag flight
- the plane driver (I hesitate to say pilot) is a klutz, and it helps him not f*ck it up.
It also killed quite a few.
It wasn't that unstable in pitch.
It had other problems.
Probably the worst of which was the guaranteed engine cut just as you cleared the boundary fence and didn't adjust the mixture.
And a propensity to spin viciously, due to a relatively small tailplane.
which was a blessing or a curse, depending on whether you could get out of it or not.
Plus the gyroscopic effects of a rotating engine, made it 'interesting'..
Well having a rudder that acted like elevators was interesting.
The C of G can and has been adjusted by adding ballast, made from spent uranium to the front or back of an aircraft, providing that the aircraft was designed conventionally as a stable one.
Its amount of stealth does not alter its ability to fly to any extent. Stealth is built into the airframe by careful use of angles and attention to gaps between panels. The idea of stealth is to reduce the aircraft's radar profile down to the size of a small number of birds and to reduce the heat that comes from the engines. To some extent, this can be done by sucking in more air than the engine requires and bypassing it to shroud the jet exhaust plume heat. There are other ways though.
That said, there are devices that can look at the sky and tell you what flew through it earlier.
Dave
Have you looked at a stealth fighter? it is angled because it was the only way to do it with the CAD they had when it was designed. It is more like a flying brick than a plane. The stealth bomber is a much more refined design and flys much better than the fighter. The raptor is yet another step forwards.
The stealth fighters are easy to track if you have a large number of transmitters and a few well placed receivers. The angles are all computed to stop stuff being reflected back to the transmitter with the assumption the receiver is co-located. The bombers have better absorbing surfaces but you can track them by monitoring the changes in the EM field as they pass over transmitters.
Looked at one? I spent nearly 20 years on them where I worked. We had a radar building that had bay windows at the back that looked at a mobile canvas hangar. Each bay window had a radar mounted in it. Aircraft were only put in there at night when there was heavy cloud cover, so the satellite's couldn't see the ground.
It was angled due to the work of the radar people, not CAD
A brick would have been seen without a radar.
If I remember rightly, wasn't it the B1 stealth bomber coming over from the USA quite a few years ago? Friday, or Saturday?
I am not clued up on the US aircraft, but it was definitely a stealth model, to take part in a flying display in the UK?
At the time, I was taking all the overtime I could to top up my pension pot and I was working for the production side of things to see off and marshal back a Tornado F3. I got him up and running and he came back and did his fly past to announce he was back and I marshalled him back in.
He raised the canopy and I can't remember if it was the pilot, or navigator that told me that the stealth bomber was coming in, as he had seen it on his radar out in the Atlantic.
Don't know about that.
Do you work in this field then?
Dave
Basic physics, really.
Take that as a 'no' then?
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