Jonmalibuss Posted February 1, 2006 Report Share Posted February 1, 2006 Alright, time for the answer.... It will NOT fly----The only way a plane generates lift is by air flow around the wings.... if the belt is keeping the plane stationary there will be no air flow and it wont take off. <{POST_SNAPBACK}> I strongly disagree! Why would there be no airflow over or under the wings? Why do you think the plane would stay stationary? If this was the case then think about the speed of the treadmill which is supposed to match the speed of the plane in the opposite dirrection. If the plane isn't moving forward then the treadmill would not be moving. Your trying to say the plane would go no where at WOT??? As for the Dyno example that is like comparing apples to oranges. Your car/truck is moved down the road by turning your wheels. A plane is not it will move forward no matter what, the thrust from the engines is going to be pushing it forward, it doesn't matter how fast the wheels are spinning. Link to comment Share on other sites More sharing options...
ssfromsd Posted February 1, 2006 Report Share Posted February 1, 2006 Am i the only one here whose dad was a Pilot? haha. Just a correction the air on the top of the wing moves faster I.E. spreading the air particles out like a vacume sucking it upward. Working along with the high pressure air underneath creating higher pressure like a leaf blower blowing it upward. Get what im sayin here. the wing needs to be going foreward from the ground that the tread mill is on. The speed should def be higher than 40 or so if it is not an ultralight... Link to comment Share on other sites More sharing options...
Big O Posted February 1, 2006 Report Share Posted February 1, 2006 You guys are killing me .... think about it. You are correct ... the lift is cause by air currents / force ... but the treadmill is completly stupid. Think water aircraft ... no wheels ... still takes off just fine ... same principle ... it doesn't matter what happens to the wheels ... you can take the damn things off and it would still work ... The plane is put in motion by propolusion ... once in motion the current and airflows will take over ... the wheels are only on there to stop the plane from smashing into the ground ... The earth is moving in the opposition direction ( what would need to happen to offset the propolsion ) just the ground .... Link to comment Share on other sites More sharing options...
dcairns Posted February 1, 2006 Report Share Posted February 1, 2006 I say the plane will take off. Remember the plane is exerting it's power between itself and surrounding air. Not like a car, which transmits it's power to the ground through the wheels. So what the wheels are doing, is largely irrelevant. There are a few practical considerations, such as, can the landing gear and wheels handle the increased rotational speed and will the plane have enough extra power to overcome the increase in rolling resistance posed by the 'belt'. Link to comment Share on other sites More sharing options...
Dirt.boy Posted February 1, 2006 Report Share Posted February 1, 2006 Aussumption #1: Plane speed is measured as air speed. (although the answer is the same using ground or absolute speed as meassured by a GPS or similar) Answer: The plane will fly. Plane will accelerate up to speed and conveyor will match plane's speed in the opposite direction. The pilot reading the plane's speed through the air will not see any difference from a normal takeoff. If the pilot happens to read the gauge showing the speed of the wheels it will read that the wheels are spinning twice as fast as "normal". Assumption #2: Plane speed is measured as wheel speed. Answer: Problem is invalid. When the plane's wheel's begin to spin the conveyor will react in the opposite direction. The conveyor speed can only add to the existing wheel speed. Any additional conveyor speed will then only compound the difference in speed. The conveyor speed can only match the measured wheel speed if the plane isn't moving. Therefore the model is not valid, because the only way to get the wheels moving is to get the plane moving and once the plane is moving there is no way the conveyor can match its speed to the speed of the wheels. Link to comment Share on other sites More sharing options...
zippy Posted February 1, 2006 Report Share Posted February 1, 2006 i suppose this question would matter if it is a prop plane or jet propelled. a prop plane create's it's own wind and should get enough coming off the prop to create lift at the wing. a jet plane creates wind from plane speed. a jet type would work the same as if you were pushing a cart on the same conveyer. there would be just enough push on the plane to keep it from going backward. a prop type plane would be the same as pulling the same cart on the conveyer from the front, except the prop creates alot of wind and wind is what lifts the plane. this would probably work just like flying a kite. Link to comment Share on other sites More sharing options...
SSThunder Posted February 1, 2006 Report Share Posted February 1, 2006 Plane won't fly. The plane needs wind. If it isn't going any where then there is no wind. Sure the plane has thust, but it needs wind to create lift. No wind, means no fly. It's a good question. But think about it. A plan needs to reach a certain speed to take off(needs enough wind moving over and under the wings). If the plane never moves, then there is no wind to create lift. Sure you'll get some wind front the prop, but not enough to lift the plane. Link to comment Share on other sites More sharing options...
pimpndevil Posted February 1, 2006 Report Share Posted February 1, 2006 It would fly!!!!!! Because the plane would move regadless of the conveyor. Planes move by moving the air not the tires like a car.Look at like this put a jet pack on your back and stand on a treadmill with roller skates !!!! I bet you won't stay on the treadmill no matter how fast the treadmill moves!!!! Link to comment Share on other sites More sharing options...
zippy Posted February 1, 2006 Report Share Posted February 1, 2006 It would fly!!!!!! Because the plane would move regadless of the conveyor. Planes move by moving the air not the tires like a car.Look at like this put a jet pack on your back and stand on a treadmill with roller skates !!!! I bet you won't stay on the treadmill no matter how fast the treadmill moves!!!! the jetpack would be pointing down. the thrust pointing down would lift you. the jet pack with you leaned over and on roller skates would just keep you on the treadmill. Link to comment Share on other sites More sharing options...
SSThunder Posted February 1, 2006 Report Share Posted February 1, 2006 Wind is what causes the plane to lift off the ground. If you don't move through the air, there is no wind. No wind, no fly. It would fly!!!!!! Because the plane would move regadless of the conveyor. Planes move by moving the air not the tires like a car.Look at like this put a jet pack on your back and stand on a treadmill with roller skates !!!! I bet you won't stay on the treadmill no matter how fast the treadmill moves!!!! <{POST_SNAPBACK}> Link to comment Share on other sites More sharing options...
2006LS2TB Posted February 1, 2006 Report Share Posted February 1, 2006 The more I think about this, I am 100% sure it will fly. For example take a hotwheels car or something and put it on a book. Pull the book backwards and the car will stay stationary on the book. The plane will infact accelerate and be able to take off. Link to comment Share on other sites More sharing options...
Big O Posted February 1, 2006 Report Share Posted February 1, 2006 Why do you think the plane will stay in one spot and not move due to the propolusion? Lets think about a missle .... it doesn't need wind to fly but moves forward due to the propolsion ... put a missle on a stand with wheels on the treadmill ... the missle would take off without a problem ... yes? Once the jets ( missles ) start firing and the moving forward ... the air current will work just as normal ... you guys are overthinking this problem ... Link to comment Share on other sites More sharing options...
Big O Posted February 1, 2006 Report Share Posted February 1, 2006 It would fly!!!!!! Because the plane would move regadless of the conveyor. Planes move by moving the air not the tires like a car.Look at like this put a jet pack on your back and stand on a treadmill with roller skates !!!! I bet you won't stay on the treadmill no matter how fast the treadmill moves!!!! <{POST_SNAPBACK}> the jetpack would be pointing down. the thrust pointing down would lift you. the jet pack with you leaned over and on roller skates would just keep you on the treadmill. <{POST_SNAPBACK}> ah zippy come on .... you are smarter than that ... what if the guy laid down on the ground next the belt and fired up the jet pack? he would go screaming down the runway with a huge rash ... now move him over to the belt and put some skates on him ... he goes flying down the run way with no rash ... but a huge brown spot in his pants. Link to comment Share on other sites More sharing options...
zippy Posted February 1, 2006 Report Share Posted February 1, 2006 remember that until lift happens you are on this conveyer. the conveyer wouldn't let you take off because you are still on it and it is moving as fast as you. you can't forget that part of his question involves the conveyer being able to move as quick as you. until you lift you wouldn't go forward. this is where it becomes difficult. this is also the same reason jet powered planes are launched off of it. without enough speed, they go down at the end instead of up. without enough forward motion for the wind a jet powered plain doesn't go up. Link to comment Share on other sites More sharing options...
2006LS2TB Posted February 1, 2006 Report Share Posted February 1, 2006 Big O, I don't think the plane will stay staitionary. What I was saying with the hotwheel example is that even though the "conveyor belt" was moving it had no efffect on the car itself except for the tires turning but the car did not change its locatino on the book. So if the plane was traveling 20 mph and the conveyor belt was traveling in the oposite direction I don't see how it could have any effect on the plane other than making its wheels turn twice as fast. Link to comment Share on other sites More sharing options...
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