RichR
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quote:
Originally posted by Ian
quote:
Originally posted by Steve
i think everyone assumes the belt has its own power and the plane is free to move.
In this instance, I fail to see how an aircraft propelled by thrust on its wings would fail to move.
Does this mean sea planes can't take off if there's a current? WTF.
they struggle and this is what lead to the isle of wight - Southampton Sea Plane being dropepd from service after 6 months in 1962 - even with the funding and passenger numbers
in the high currents of the Solent it struggled to take off
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RichR
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Location: Waterhouses, Staffordshire
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I never once said ti was powered by the wheels - I said it transmitted its forward propulsion through its wheels - so Paul J kindly get your facts right
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Paul_J
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Live_lee, only kidding mate  I get where your coming from 
Just felt that sometimes you would just post anything up - how relevant or not it was. like how the power of jet propulsion is calculated.
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SVM 286
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quote:
Originally posted by Jules S
quote:
Originally posted by SVM 286
quote:
Originally posted by Sxi04
...can you tell me what would happen if the conveyor underneath the aircraft is moving at five times the speed of the aircraft itself? discounting tyre blowouts and other variables
Yes Mr. 04, the craft would exit the rear of the conveyor unless the engines were powered up to compensate.
No it wouldnt,
the planes wheels would simply spin faster.
The only force that has an ability to move the plane forwards are its propulsion system (the jets)
The plane isn't fixed Jules.
It is an unconnected body.
It will of course fall off the back of the belt if the engines don't stop it. Much in the same way you would fall off a tread mill if you walked too slowly or stopped walking.
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Ian
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Registered: 28th Aug 99
Location: Liverpool
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Actually thats a bad example - the current would offer drag on the floats and therefore slow the plane.
The belt as I'm aware wouldn't offer the same resistance to the road wheels of a jet plane, which have very low frictional coefficient compared to the engine thrust.
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DarrenGSi
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can you see my way of thinking though
conveyor is at Xmph, plane is not being propelled, this causes the plan to go backward, its sitting on the same piece of conveyor constantly.
after 5 mins the plane still has no power, so is still not moving.
after 5 mins, the plane starts to accelerate but ONLY up to Xmph.
so the plane is now thundering along at Xmph on the conveyor also going Xmph.
now if you were standing in the control tower looking at the plane, it would appear not to be moving because the plane is going an opposite direction from the belt and both are at Xmph.
after 5 mins of watching the plane appear to be on the same spot the pilot tries to lift the nose to take off but guess what, the nose doesnt lift because the wings do not have air passing by them to lift the plane.
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RichR
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Location: Waterhouses, Staffordshire
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I didnt I put how thrust was calculated - after you said it had no relationship to speed - when infatc it has a great relationship with both jet and ground velocity
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SVM 286
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quote:
Originally posted by John
Darren and SVM are just totally wrong in general.
John, I apologise if I have offended you.
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Jules S
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Registered: 24th Dec 03
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quote:
Originally posted by LiVe LeE
quote:
Originally posted by Ian
quote:
Originally posted by Steve
i think everyone assumes the belt has its own power and the plane is free to move.
In this instance, I fail to see how an aircraft propelled by thrust on its wings would fail to move.
Does this mean sea planes can't take off if there's a current? WTF.
they struggle and this is what lead to the isle of wight - Southampton Sea Plane being dropepd from service after 6 months in 1962 - even with the funding and passenger numbers
in the high currents of the Solent it struggled to take off
On a runway the size of a postage stamp with no where near as thrust as engine produce these days 
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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runway - its a fucking estuary the size of about 50/60 runways
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SVM 286
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quote:
Originally posted by John
quote:
Originally posted by SVM 286
quote:
Originally posted by robmarriott
I'm with Paul here
plane would move down the conveyor belt even if it was on skis
It can't Robin.
The conveyor travels at the SAME speed as the aircraft.
We have to consider that a constant in this case or we are wasting our time mate. 
You showed you didn't have a clue with your comment before.
The plane would not go backwards off the conveyor showing you don't understand.
Yes it would John. Primary school physics realy.
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Ian
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Registered: 28th Aug 99
Location: Liverpool
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quote:
Originally posted by DarrenGSi
after 5 mins, the plane starts to accelerate but ONLY up to Xmph.
This assumes that the frictional resistance which the thrust must overcome is generated by the ground and not the air.
The belt via the wheels would not slow the plane sufficiently to counteract thrust.
The thrust would continue to propel the plane in the same way as if the belt were not involved.
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John
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Registered: 30th Jun 03
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U've not offended me at all SVM.
But you are still arguing a lost cause lol.
If its primary school physics why do you not get the point.
[Edited on 24-05-2006 by John]
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Jules S
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Registered: 24th Dec 03
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quote:
Originally posted by LiVe LeE
I never once said ti was powered by the wheels - I said it transmitted its forward propulsion through its wheels - so Paul J kindly get your facts right
Please oh please oh please explain to me how much propulsion is transmitted through the near frictionless wheel bearings?
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SVM 286
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quote:
Originally posted by John
Are you kidding SVM?
No John, i'm quite quite serious.
The physics are so simple it's staggering that you are incapable of concieving them.
If an aircraft landed on a conveyor travelling in the opposite direction to it but at the same speed, the plane would need to maintain speed to prevent from falling off the back of the belt.
As the engines' and subsequently the craft's speed slowed, the craft would be propelled off the back of the belt if the belt maintained it's velocity.
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DarrenGSi
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Registered: 11th Jul 05
Location: East Ayrshire Drives: Civic Jordan 381
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quote:
Originally posted by Ian
quote:
Originally posted by DarrenGSi
after 5 mins, the plane starts to accelerate but ONLY up to Xmph.
This assumes that the frictional resistance which the thrust must overcome is generated by the ground and not the air.
The belt via the wheels would not slow the plane sufficiently to counteract thrust.
The thrust would continue to propel the plane in the same way as if the belt were not involved.
yes it would ian but as you know, there can be no more thrust than is used to get the plane to the same speed as the belt as the question says they are the same speed. if they are to be the same speed how cn the plane use thrust?
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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its not to do with thrust or plane speed tbh - the whole debate hinges on velocity of advance and wether ti would happen - would the plane speed exceed the wheel/conveyour speed
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John
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Registered: 30th Jun 03
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Because you used velocity in your explanation does not mean you are correct svm.
You are showing more and more stupidity as you reply.
Its not even just to this question.
Its showing a total lack of understanding.
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SVM 286
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Location: pain
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quote:
Originally posted by robmarriott
But Jim, the wheels would prevent the plane from stopping dead, they would turn, and allow the plane to continue to move
reverse the theory, the plane can still move from a conveyor as the wheels allow it to
Wheelspeed is not a concern Rob. Identical vehicle speed and conveyor speed are the two factors.
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John
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SVM 286
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quote:
Originally posted by John
Darren thats your credibility gone out the window.
SVM who has already contradicted himself agrees with you.
When did I contradict myself John.
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Robin
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so you are saying the wheels are fixed and wont turn? then the plane is broken.
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Ian
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Registered: 28th Aug 99
Location: Liverpool
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quote:
Originally posted by DarrenGSi
there can be no more thrust than is used to get the plane to the same speed as the belt as the question says they are the same speed. if they are to be the same speed how cn the plane use thrust?
In the wishy-washy crap question, yes.
In the real world, where ground speed IS NOT a factor, the belt COULD NOT speed up sufficiently to counteract the thrust.
The fact that the belt speeds up to meet and offer an opposite force to the plane is a moot concept.
What you're basically saying to me is that the frictional loss through the wheels as offered by the belt is sufficient to overcome the jet thrust, something which would need a considerable amount of belt speed indeed.
Wheel speed less important than the force which countacts the thrust - and the wheels are near frictionless in the grand scheme of things.
[Edited on 24-05-2006 by Ian]
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SVM 286
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quote:
Originally posted by DarrenGSi
svm i think your wrong bout the landing theory but correct bout the take off,
if the plane is landing it will gradually slow down then go backwards the same speed as the conveyor, not stop dead tho
Not if the belt and craft are travelling at exactly the same speed when the craft lands on the belt Darren.
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RichR
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Registered: 17th Oct 01
Location: Waterhouses, Staffordshire
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conveyour speed should in theory be the same as the outer diameter of the wheel's speed
the debate I'm putting acorss is if the conveyour/wheel speed is different to the planes thrust speed
if it is different there will be a velocity of advance - if its the same there wont be
this velocity of advance will determine if the plane reaches take off speed
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