Some serious DIY modelling!

I have never thought about that. Was it moved back, or forwards? And I spent 21 years working on this. :-(

Dave

I'll get back to you on this when I phone my model flying mate.

Dave

Without destroying my link back to this, just what is the path of the intake to the engines?

Dave

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember Dave saying something like:

center of lift is ALWAYS on the center of gravity, by definition.

Stability is satisfied if a rising nose or falling airspeed moves the center of lift backwards and vice versa.

i.e. its the first differential of lift with respect to airspeed, angle of attack, or both that defines stability in pitch..

Normally any stability issues can be solved by moving the CG forward, and compensating with up elevator.

Forwards.

So why does a paperclip on the nose end make a paper plane flyable?

Chris

technology!

Assuming that's not a wind up, this is the same thing

Because it encourages the center of lift and center of gravity to coincide *with the plane in a nice glide*.

A falling bomb is nice and stable too. But it doesn't glide very far..

Dnt confuse stability, with performance in other areas.

Anyway, MY paper planes don't need paperclips ;-)

I don't think that clockwork technology met with a great deal of success in the aviation world

I feel thick now, knowing that. Hence the canards at the front being the deciding factor.

Dave

Youtube" sites but my browser hates 'em but is always fine with "the same content" if it exists on YT.

Initial comment: should have made the plane a little bigger, then he could have sat in it and it would have been even more fun :-)

I don't know about engine vs. engines - about 1:35 when it starts moving, it looks like the grass is being blown all the way across the back, not just in the middle, but that might just be an effect of the low quality / high compression in the vid itself.

Is it possible that the engine(s) are mounted inboard in the fuselage, but ducted via the wings to the 'normal' engine exhausts? I'm not sure if that'd work without too much flow restriction (or problems with overheating). I'm sure it'd be possible with the intakes though (although maybe there's an intake toward the front on the underside of the fuselage

- I'm not sure if it'd be possible to see it in the video even if there was)

cheers

Jules

No it isn't. I have, on and off spent the last 30 years working on turning stable centre of lift aircraft into fly by wire that were unstable.

Starting with a Jaguar that was made slightly unstable by changing the aerodynamics. Computers were added to compensate for flight for the pilot.

Followed by the EAP (Experimental Aircraft Project). This had canards at the front. This resulted in the development of the eurofighter Typhone.

Dave

It puts its centre of gravity over the centre of lift. The *basic* principle of flight. As the NP says.

Fly by wire is different, much different.

Dave

I worked on that in the aerospace industry for many years. Did I do OK then?

Dave

canards at the front require a very forward CG, or if you think of them as aircraft with very large tails. a very rearward one ;-)

Shame you didnt do a basic physics course first.

The function of fly by wire is to make sure that the CG IS at the centre of lift, at all times..moving the elevators changes the center of lift dramatically ;-)

Go back and check your definitions., I know what you are saying, but it isn't the correct way to say it.

No, I said it puts it there when its in a stable gliding attitude. Center of lift varies all over the place depending on airspeed and attitude.

If it isn't at the center of lift, teh plane will fall over. Fly by wire wire is equivalent to riding a unicycle. It can be done, but requires constant input.

Normal planes are like sitting in a unicycle with te tyre removed suspended upside down. by a cable. It's stable.

Its the confusion between the first differential of lift position with lift position itself. If the centre of lift e.g. moves aft as the plane puts its nose down, and the weight is not low enough for some sort of pendulum stability, its unstable in pitch and will tend to 'tuck under;' Its VERY hard to fly a plane like that, and beyond a certain limit, impossible. Pull the nose up, and it responds by snapping into a stall.