1Quik7 Posted January 31, 2008 Report Share Posted January 31, 2008 Sentiments agreed with... I thought the 'myth' was that a treadmill that matches the speed of the plane...will not allow the plane to take off All of their 'tests' allowed the plan to far exceed the speed of the treadmill. I thought they would be trying to match the speed attained by the propeller (very difficult to do) The only 'myth' they busted was whether a plane can take off when a conveyor belt slows it down slightly exactly...the 'myth' is that if a "treadmill" matches a planes Vr speed (at which it can rotate and gain lift) the plane won't go anywhere...it says nothing about a plane going beyond it's Vspeed(which is the catch)...however...if the Vr speed is 25mph for 'said' plane (which is extremely low)...and the tarp is being pulled away at 25mph..it would need to compensate for this loss, but it had 2000ft to do so...which is why i said booo for an Ultralight, it still goes back to the original mistakes of the thread...most people thought the plane and tread would "match" speeds...from all the responses i saw...i honestly thought people thought the propeller creates the wind that creates lift on the wings. in the end it was a simple answer....it's just a hard question to explain. Quote Link to comment Share on other sites More sharing options...
Sully Posted January 31, 2008 Report Share Posted January 31, 2008 OK, I didn't read the entire thread so I don't know what all was said. But from the way I saw it, the plane did not stay still, which meant that the plane was going faster than the treadmill. If the plane was standing still, it would not have taken off. But, since the guy flying the plane got it going faster than the treadmill, it moved forward, which caused air under the wings, which gave it lift. When they are able to get the plane to stay still on the treadmill, then it will not fly. I have a feeling that this "myth" will create so much controversy that they will have to do it again. I thought they were suppose to keep the plane at the same speed as the treadmill, which means that it would be stationary. But that's not what they did. Quote Link to comment Share on other sites More sharing options...
spankis Posted January 31, 2008 Report Share Posted January 31, 2008 Wow, people STILL won't give in. I just watched this on the DVR. Ridiculous. Believe it kids. Pilot on the show = dumb, not gonna lie. Quote Link to comment Share on other sites More sharing options...
87GT Posted January 31, 2008 Report Share Posted January 31, 2008 The wheel spins twice as fast as the conveyor belt? Quote Link to comment Share on other sites More sharing options...
HAOLE Posted January 31, 2008 Report Share Posted January 31, 2008 Wow, people STILL won't give in. I just watched this on the DVR. Ridiculous. Believe it kids. Pilot on the show = dumb, not gonna lie. I am not sure how that guy got a license. Quote Link to comment Share on other sites More sharing options...
Furloaf Posted January 31, 2008 Report Share Posted January 31, 2008 You don't have to be an automotive engineer to get a Driver's license, do you? Quote Link to comment Share on other sites More sharing options...
TA In Progress Posted January 31, 2008 Report Share Posted January 31, 2008 The only way it wouldn't have taken off is if the axle (spindle) nuts were so tight that the wheels wouldn't turn, they had a brake locked up, or they left the emergency/parking brake set (Creating more drag than the engine could overcome). Even then, it might still go. That said, I've had several planes come in at night with locked up brakes and overtorqued wheels, and they still took off, there just wasn't much left of the tire once it landed. Quote Link to comment Share on other sites More sharing options...
Draco-REX Posted January 31, 2008 Report Share Posted January 31, 2008 Other way around, they tried matching the treadmill to the plane's takeoff speed (~90mph I think), but it just didn't matter because the non-powered wheels are relatively frictionless. There's no controversy, the plane takes off because it's not powered by the wheels - which might as well have been giant ice cubes. I feel like a broken record. The plane's takeoff speed was 25. Considering a Truck can accelerate faster than a plane to 25mph, the treadmill was actually going faster than the plane. It still took off, which kills the arguments about the plane's speed vs treadmill. I think one problem that people are having is that they INTERPRETED the question to mean that the plane would be held stationary as part of the experiment. Unfortunately, that's wrong. The components of the experiment were: 1 Plane in takeoff procedure, 1 Treadmill acting in opposition to the plane's forward movement. That's it. You cannot interpret or apply meaning to an experiment or you skew the results. You have to run the test as designed. I'm sure peopel will start saying they should have kept the plane stationary, but that's not how the question was worded. If you try to keep the plane stationary, you're applying your interpretation to the question and FORCING the results to conform to your preconceptions. That is NOT science, it's politics. Quote Link to comment Share on other sites More sharing options...
SPLN SUX Posted January 31, 2008 Report Share Posted January 31, 2008 I am not sure how that guy got a license. I dont even have a license and knew what would happen... wheres all those people that were so sure it wouldnt take off? Quote Link to comment Share on other sites More sharing options...
Nitrousbird Posted January 31, 2008 Report Share Posted January 31, 2008 There sure are a lot of stupid people out there. Some of them just happen to post on this message board. If you thought the plane wouldn't take off, you are stupid. And I didn't watch the show. If being called stupid offends you, well, that sure sucks, huh. Quote Link to comment Share on other sites More sharing options...
Tractor Posted January 31, 2008 Report Share Posted January 31, 2008 don't matter if the planes take off speed is 25 mph and the treadmill is running 1,000 mph backwards the plane will still take off. The treadmill has NOTHING to do with the plane moving forward and cannot prevent the plane from moving forward. The reason for this is the invisible force of the prop against the air around it. The faster the plane is moving backwards at the time the prop begins turning the more pressure (read that force) the prop will have to "dig in" to the air and start negating the backwards movement of the treadmill. I understand how some people wouldn't get this and won't call anyone stupid over it. Some people just understand other things better than others. Physics of flight are something I happen to understand enough to get it. BTW I don't watch that show. I can't stand the format of all these new TV shows. I liked the old dry way of learning on TV. Evan Quote Link to comment Share on other sites More sharing options...
PCarillon Posted January 31, 2008 Report Share Posted January 31, 2008 The plane's takeoff speed was 25. Considering a Truck can accelerate faster than a plane to 25mph, the treadmill was actually going faster than the plane. It still took off, which kills the arguments about the plane's speed vs treadmill. I think one problem that people are having is that they INTERPRETED the question to mean that the plane would be held stationary as part of the experiment. Unfortunately, that's wrong. The components of the experiment were: 1 Plane in takeoff procedure, 1 Treadmill acting in opposition to the plane's forward movement. That's it. You cannot interpret or apply meaning to an experiment or you skew the results. You have to run the test as designed. I'm sure peopel will start saying they should have kept the plane stationary, but that's not how the question was worded. If you try to keep the plane stationary, you're applying your interpretation to the question and FORCING the results to conform to your preconceptions. That is NOT science, it's politics. It wouldnt matter if he accerated the truck to 100+mph the plane uses thrust from the proppeller to make it move and fly so it doesnt matter what the ground is doing it will still propel itself and take off... the planes wheel speed will just increase compared to the conveyor belt ex:25mil take off speed + conveyor belt speed 100mph so the planes wheel speed is 125 mph yet the actually planes speed is still 25mph... its simple Now throw a 25mph tail wind at it and it wont take off until the plane speed reaches 50mph Quote Link to comment Share on other sites More sharing options...
hot_wire Posted January 31, 2008 Report Share Posted January 31, 2008 If the plane moved forward at all, the treadmill didn't move fast enough. I interpreted the question to mean that the treadmill matched the planes forward speed no matter what. The plane would not have moved if the treadmill was capable of going infinitely fast (as I interpreted it). The real world version, yes the plane flies. My hypothetical and currently impossible to implement interpretation - Its still on the ground with overheated wheel bearings! Quote Link to comment Share on other sites More sharing options...
hot_wire Posted January 31, 2008 Report Share Posted January 31, 2008 It wouldnt matter if he accerated the truck to 100+mph the plane uses thrust from the proppeller to make it move and fly so it doesnt matter what the ground is doing it will still propel itself and take off... the planes wheel speed will just increase compared to the conveyor belt ex:25mil take off speed + conveyor belt speed 100mph so the planes wheel speed is 125 mph yet the actually planes speed is still 25mph... its simple Now throw a 25mph tail wind at it and it wont take off until the plane speed reaches 50mph Think of the drag on the planes wheels if the truck went 200mph. Now 700mph. The drag on the wheels at 3000mph would be incredible and definitely prevent the plane from moving forward. Wish my truck could go that quick --- I'd show you all!!! :woowoo: Quote Link to comment Share on other sites More sharing options...
PCarillon Posted January 31, 2008 Report Share Posted January 31, 2008 If the plane moved forward at all, the treadmill didn't move fast enough. I interpreted the question to mean that the treadmill matched the planes forward speed no matter what. The plane would not have moved if the treadmill was capable of going infinitely fast (as I interpreted it). The real world version, yes the plane flies. My hypothetical and currently impossible to implement interpretation - Its still on the ground with overheated wheel bearings! Wrong HOt the plane doesnt get its forward speed from its wheels it gets it from the prop that is creating thrust so I dont care if you hooked the treadmll up to the shuttle its still taking off.for what you are tring to say to work you would need a head wind that matches the movement of the plane so if takes 25 mph of thrust to take off then a 25 mph headwind would theoretically keep the plane stationary but with the loft created by the head wind going over the planes wing surfaces the plane should still leave the ground and fly but not move.THE GROUND MOVING has no effect on a planes movement Quote Link to comment Share on other sites More sharing options...
Tractor Posted January 31, 2008 Report Share Posted January 31, 2008 Someone draw a picture of an airliner with 30,000 foot long wheel supports because I still get the feeling some people think planes get power from wheels and the prop blows air over the wings. Evan Quote Link to comment Share on other sites More sharing options...
KillJoy Posted January 31, 2008 Report Share Posted January 31, 2008 The prop pulls the plane...... true The wheel roll on the ground..... true The prop pulls the plane, and the plane's wheels roll on the ground. If the ground moves at an equal speed of the wheels, for the plane to be stationary, it WILL NOT FLY. Just like a person on a treadmill. Why do you not run into the Wall? The treadmill is moving at the same speed you are, and you stay stationary. KillJoy Quote Link to comment Share on other sites More sharing options...
Tractor Posted January 31, 2008 Report Share Posted January 31, 2008 Umm... Should I even respond to that? I think he's beyond help on this matter. Ok go get a treadmill and walk on it. You don't move right? Cool, now get a toy car or something and push it on the treadmill. Now turn on threadmill and push it again. No difference the wheels don't connect mechanically to the treadmill and you can push the toy car off the threadmill. We relate your arm pushing the toy car to the prop pushing against air. These two things are unrelated to what the treadmill does. No mechanical link = no possible effect on each other. Someone draw the picture quick:-) Evan Quote Link to comment Share on other sites More sharing options...
Science Abuse Posted January 31, 2008 Report Share Posted January 31, 2008 Jesus tap dancing christ, people are still talking about this? It's bee proven foo'z! Find somethig else to talk about. Quote Link to comment Share on other sites More sharing options...
Nitrousbird Posted January 31, 2008 Report Share Posted January 31, 2008 The prop pulls the plane...... true The wheel roll on the ground..... true The prop pulls the plane, and the plane's wheels roll on the ground. If the ground moves at an equal speed of the wheels, for the plane to be stationary, it WILL NOT FLY. Just like a person on a treadmill. Why do you not run into the Wall? The treadmill is moving at the same speed you are, and you stay stationary. KillJoy See the post I made a few above yours. You are one of those people. Quote Link to comment Share on other sites More sharing options...
KillJoy Posted January 31, 2008 Report Share Posted January 31, 2008 See the post I made a few above yours. You are one of those people. If you are calling me stupid, I am calling you an ass. KillJoy Quote Link to comment Share on other sites More sharing options...
smokinHawk1647545499 Posted January 31, 2008 Report Share Posted January 31, 2008 If you are calling me stupid, I am calling you an ass. KillJoy if you still dont believe i agree with the populous you are the dumb. Quote Link to comment Share on other sites More sharing options...
HAOLE Posted January 31, 2008 Report Share Posted January 31, 2008 If you are calling me stupid, I am calling you an ass. KillJoy Joe is on to something! Quote Link to comment Share on other sites More sharing options...
HAOLE Posted January 31, 2008 Report Share Posted January 31, 2008 You don't have to be an automotive engineer to get a Driver's license, do you? To get a pilot license you but understand how they fly. Flight school 101 Quote Link to comment Share on other sites More sharing options...
KillJoy Posted January 31, 2008 Report Share Posted January 31, 2008 What if the wheels are taken out of the equation? Imagine square blocks instead of the wheels. This rules out MY thoughts on the treadmill, in essence. Will the plane still take off? If so, why? KillJoy Quote Link to comment Share on other sites More sharing options...
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