Sorry I missed the beginning of this thread. Schmism, you devil you.
Anyway, I was on vacation, and when I got back I was out on my tractor. Well, I finally came in and turned on the computer and saw this thread. You wouldn’t have had such passionate responses to the question: Blue, green, or orange gear or hydro synthetic. Tractors are still kinda new to me but I do know a thing or two about airplanes. So here are some analogies that might get you non-believers over on the side of truth, freedom, and the TBN way.
I’m not going to debate the interpretation of the wording of the question. I think it’s pretty clear, but then again, others don’t always see things the way I do. Therefore, this is mainly for those who see the “Magic Conveyor Belt” (or MCB) as the stumbling block to this airplane’s eventual stabilized departure. I will use real world materials for my ideal airplane which will help you envision the reality a little easier. I will also use real world physics, with the exception of the movement of said conveyor belt. Here goes…
The Plane: The ideal plane would have a very large aspect ratio (think glider wing) and a very large thrust to weight ratio (powerful engine, light plane). The one that jumps to mind is the U2 (that Kelly Johnson was amazing). Change out the engine with say an F100 (F15, F16 engine… gobs of power) or something similar. The tires would need to be very hard and smooth, almost slick with very high air pressure. Oh, I know how about this… solid Teflon. Then we’ll change out the wheel bearings and axles. New super-high speed, high temp, roller bearings and axles. No holds barred when you’re dealing with magic.
The Set Up: Now the next thing you need to understand is that there is no mechanical connection between the conveyor belt and the airplane. There is friction (mass, gravity, coefficients and all that garbage), but that’s it. Also, there is no mechanical connection between the wheels and the airplane. Now it’s getting good. The wheels spin freely. Spin em’ forward, backwards, stop them, the plane doesn’t care.
The Analogies: What happens when an airliner touches down during landing? It doesn’t stop immediately does it? When the wheels first touch the runway their rotation is zero even though they are moving through the air at say 140 knots. As the wheels contact the ground friction comes into play. There is a puff of smoke as the rubber boils and vaporizes due to the friction between the ground and the tires. It sometimes takes over a hundred feet for the tires to spin up to a speed where there is no longer slippage and… friction increases. This is key. Friction decreases as the speed between the objects increase. More on this in a second. The airliner hasn’t slowed down a bit from this violent impact. Ground spoilers and thrust reversers are deployed to reduce the lift from the wings and increase friction between the tires and runway to allow the brakes to stop the plane.
The next analogy for you ground bound folks. Take an older car or truck i.e. no anti-skid brakes. You’re cruisin’ at highway speeds, say 80-90 mph… err… I mean 55-65 mph and slam on the brakes. Smoke rubber on pavement, but you don’t stop for a couple of hundred feet.
The Flight Test: With our souped up U2 on the MCB runway with just enough fuel for a short flight and all unneeded instrumentation removed, we’re ready. Now if the MCB wanted to maximize friction it would spin up slowly to maintain an equal speed between the wheels and the belt, but if it did that, the U2 would be 1000 ft in the air before you could blink. Instead the MCB will spin up instantaneously to a thousand, a million, a billion revolutions per second, faster than the speed of light. At witch point the MCB will disappear into the space/time continuum. The U2 will then fall to the ground and takeoff normally.
Sorry, I couldn’t resist. So, as the U2 pilot applies full afterburner and full nose up pitch, the MCB will try to rotate the wheels to restrict the airplanes forward movement. It won’t be able to, remember the analogies? The MCB can accelerate instantly (remember it’s magic) but the wheels have mass and only friction can come into play. The MCB will begin to move the wheels, but by then the U2 will move forward gliding on its super-slick bearings increasing lift and in turn decreasing friction between the tires and belt even more. Lots of smoke and some burned up Teflon tires, but the plane will be flying.
I know I said that I wasn’t going to debate semantics, but…
“a plane is standing on a movable runway( something like a conveyor).as the plane moves the conveyor moves but in the opposite direction. the conveyor has a system that tracks the speed of the plane and matches it exactly in the opposite direction”
Where is the magic conveyor belt?
Now pardon me I’ve got some work to do… on my TRACTOR.
