A brainteaser.. The Airline Short Takeoff Conveyor.

I still don't fully understand this. In my way of thinking, handrail's post, #18, is exactly how I would answer it...like with the aircraft carriers example.

Then Scholzie's post #22 brought new light with the pulling not pushing explanation.

I guess I'll never grasp this concept unless I could see it done in real life, which would be quite complicated, if not impossible, to attempt.

 

visualize thus... as stated originally, but ALSO.. the aircraft has a cable attached via 'skyhook', which can lift the aircraft.

1. the effect when engines go to takeoff power with a slack cable

2. the effect when engines go to takeoff power with cable lifting aircraft so the wheels dont quite touch the conveyor.

The wheels have nothing to do with the plane's ground and airspeed, exception being when brakes are applied to slow it.
They are only there to reduce/control friction. And the conveyor only affects the wheels.

 

To put a point on that:

someone once invented a system that would spin the wheels up to same speed they would be going in ground contact so as to "improve landing" where, the wheels are not rotating till they hit the runway, then screech violently up to speed.

It was found to have the opposite effect, wherein the weight added for such cost fuel and increased the landing run. Better to 'waste' rubber.

 

I'm still confused. So I suggest one thing. Petty, get a plane, get some nice engineers and try this out for yourself. Although, please note, I will not believe it unless YOU are the pilot.

 

So are you saying that as the engines gain more power when a plane is taking off eventually the wheels aren't truly rolling (like a car driving down a road) on the conveyor, but merely skimming along it, providing just enough control to keep the plane headed straight? if so, then i think i'm starting to understand this. if not, then my brain is taking a step backwards.

This is what I'm having trouble understanding (unless the above 'skimming along' part of this post is correct, then forget all this). I get that the wheels don't effect the plane's speed...the engines supply power, and the wheels provide control, like enabling the plane to maneuver around the runways to get into loading/unloading and takeoff positions etc. etc. But as the power of the engines increase the plane will move forward faster, causing the wheels to turn faster, which, according to the original question, would also cause the conveyor to speed up to match the speed of the wheels. This way of thinking would make the plane stay in one place, like a person running on a treadmill.

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Pettyfog's above link to thetechlounge.com got me wondering how many other forums are duking it out over this problem. mmm...

on a funny little side-note I'd like to point out that this thread got google to recognize the word conveyor and the FulhamUSA sponsor on the bottom right of the screen as I type this is for QCindustries.com which apparently is the "industry leader in conveyor belts".

 

At least it finally got rid of that Lampard banner :3d smile: