The-Hogs.net - Washington Football Discussion, Redskins to Commanders Era

Where I tend to disagree with this argument is that the a/c is not interacting with the air. While the a/c is on the ground, it is groundspeed...while in flight airspeed. Since the conveyor's opposite direction versus the a/c groundspeed matching/syncing, it would ideally keep the a/c at 0 kts of airspeed. Without the force of wind driving under the winds creating lift, it could neither achieve flight nor sustain it. And with the a/c unable to achieve forward momentum, it is impossible to receive the "headwind" necessary for flight. This theory is only true of course if the constant increase of a/c groundspeed was met with equal opposite groundspeed of the conveyor...keeping it "x marks the spot" on the conveyor.

P.S.

On the U.S.S. John F. Kennedy, I personally observed an S-3 (jet) take a cat shot (improper weight) and was unable to surpass stall speed. Due to it's lack of airspeed and headwind, it nosed into the water and was driven over by the carrier. This trajedy is just an example of how important wind/airspeed is. Anytime on my airfield that a pilot even remotely thinks he's getting a tailwind, they request a runway change (from 5 to 23, or vice versa.)

$.02

Countertrey wrote:

Anyways...scientists-schmeintists, cup. There's no lift, as noted. Try to picture the whole thing as a person on a treadmill.

Clearly, most folks here are thinking that aircraft use their wheels to provide propulsion. This is not a car. If you place a car on the hypothetical treadmill, your analogy is correct.

In the case of our aircraft, the propulsion forces will impart momentum irrespective the treadmill. The wheels, which are in contact with the treadmill, do not propel the plane.

The engines DO NOT CARE that there is a treadmill. They are interacting with the AIR, not the TREADMILL. They will force the plane forward NO MATTER WHAT speed the treadmill is travelling in the opposite direction.

UK Skins Fan gets it. Everyone else has fallen for the red herring of the conveyor belt... which has no bearing on whether the plane flys or not.

Ya'll got access to a treadmill? Buy one of those cheap, rubber band planes... try it yourself. Just be ready to catch the plane before it flies into the wall in front of the treadmill.

Whoah, hey now, I simply said I was agnostic about it ... I have gone back and forth on this one but I am pretty convinced it will, in fact, take off at this point.

Whoah, hey now, I simply said I was agnostic about it ...

as some famous dude once said "You're either with us or agin us". I'm sure that at some point he went on to butcher to word NOOOOCUELER, but that's just another story....

Where I tend to disagree with this argument is that the a/c is not interacting with the air.

Still not paying attention. Of course the AIRCRAFT is interacting with both... however, the engines are not. Air goes in one end, and comes out the other at a much higher velocity... leads to that "equal and opposite reaction" that Sir Isaac Newton was so fond of. The Engine, therefore, moves forward. The fortunate aircraft that it is attached to, gets to go with it.

Your anecdotes about cat undershots are, of course, interesting, but are completely unrelated to this hypothetical. (I was a Navy airedale for a few years, too (my first 4 years in the military... but then I discovered that soldiering was more fun)... and also sat for (and earned) my A&P license. Understanding aerodynamics and the physics of flight are a part of that.

SHE FLIES!!! The plane FLIES!!!

(fondly remembering "FOD walks"... thank you very much)

The only thing that bothers me about your angle is (and this may be my misunderstanding of the riddle) if the conveyor is counteracting the force of the jets, thus keeping it in place, how is it gaining any true airspeed? I'm really not trying to beat a dead horse here, and this is all in good fun, but we may have to agree to disagree. My opinion is the a/c in question must reach/sustain a certain amount of airspeed (stall speed) to achieve flight. I cannot see how this is possible with aforementioned conveyor keeping it from gaining forward motion. The ground speed could indicate 250 kts, but if the conveyor is counteracting this with 250 kts of opposite direction revolutions, the a/c in question could not move forward. No forward motion, imho, equates to 0 kts headwind. Without the headwind, takeoff and flight is impossible. Once again, these are the ramblings of a Naval Air Traffic Controller, only to be taken moderately serious. BTW, I respect your point of view and think you bring a valuable argument to the table.

$.02

JansenFan wrote:
Vertical Take Off and Landing

The Harrier can take off whether the treadmill moves or not. It just tilts it's wings and uses the thrust to push up instead of forward.

Other than that it's like the other dude here in the Ville said "the plane is running in place.

If the belt was to speed up and the plane not match that speed wuoldn't it lost ground? Until it falls off the back of the belt?

The only thing that bothers me about your angle is (and this may be my misunderstanding of the riddle) if the conveyor is counteracting the force of the jets

Understand that the only part of the plane that interacts with the conveyor is the wheels. While the propulsion system would have to overcome what is known as rolling resistance, this would be the only small effect of the conveyor on the ability of the plane to move forward. The only way that the reverse force of the conveyor would prevent the plane from moving forward would be if the air above it was moving in the same direction at the same speed as the conveyor.

This is because, once again, the engines interact only with the air and the airframe... not the conveyor. The wheels free-wheel, meaning that the conveyor, no matter how fast it goes, cannot prevent the plane from moving forward.

V1... V2... Rotate! Gear up!

I kinda feel stupid for not knowing this from the outset

I kinda feel stupid for not knowing this from the outset

Dude! It's all relative! For a cup with a pink straw stuck in his head, you're a friggin genious.

On the "Dixie Cup Scale of Container intelligence" (or DICSOC as we like to call it), I'm sure you are probably a MENSA candidate.

Countertrey wrote:

I kinda feel stupid for not knowing this from the outset

Dude! It's all relative! For a cup with a pink straw stuck in his head, you're a friggin genious.

On the "Dixie Cup Scale of Container intelligence" (or DICSOC as we like to call it), I'm sure you are probably a MENSA candidate.

Good point, good point

Ah! The pleasure the offseason is.

Are we talking about Danny's Redskins One? I'm sure it's on the treadmill now, getting in shape for the beginning of free agency...

The question is -- which direction is that puppy heading?

Countertrey wrote:

I kinda feel stupid for not knowing this from the outset

Dude! It's all relative! For a cup with a pink straw stuck in his head, you're a friggin genious.

On the "Dixie Cup Scale of Container intelligence" (or DICSOC as we like to call it), I'm sure you are probably a MENSA candidate.

did you realize that acronym spells d*ck sock?

I'm an idiot.

If the "treadmill" is keeping the wheels from making forward progress by counteracting all forward speed the aircraft is effectively stationary,

LOL... The treadmill has no effect on forward airspeed, because the wheels rotate freely. As a result, there is no way for the treadmill to prevent the aircraft from moving forward relative to the speed of the air above it. Beyond the effect of rolling resistance, it just can't do it. There, by the way, is the response to your "Theory of Relativity" attempt. Engine thrust interacts relative to the air, as well as to the surrounding earth which, relative to the treadmill, and the aircraft in motion, is still.


And, just exactly does your "pedegree" have to do with your or my qualifications to argue this? Do you wish a list of my relatives and friends with aviation/engineering/NASA credentials? Would it matter? Nope.

I saw Haile Selassie once.

Your correct.

Well, it's about as relevant as you telling us all you were in the Navy as an airdale.

Had YOU read the entire thread, you would have known that was in direct response to another poster's (Skinz74) use of his Naval experience. Apparently, I am the only person not permitted to make such responses in your book. MY evperience is valid. You wish me to accept that YOU have some expertise because you are a pilot. My experience is just as valid as yours. You are definitely barking up the wrong tree. You, your self, stated that your comments had no relevence.

I happen to agree. Genetics do not impart knowledge of physics.

Re-read the question.

Fine. Let's BOTH do it.

A plane is standing on a runway that can move (some sort of band conveyer). So far, so good
The plane moves in one direction, while the conveyer moves in the opposite hmmmm... BOTH are moving... and in OPPOSITE directions
direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite
direction). soooooo... if the PLANE is moving at 150 mph in one direction, then the TREADMILL is moving at 150 mph in the OTHER direction

The question is:Will the plane take off or not?


Well... don't most planes reach V2 at speeds below 150 mph????

did you realize that acronym spells d*ck sock?

Well, of course. I mean, it is a test for cup intelligence, and all... I could have arranged it so the o in sock was a u, but, you know, discretion being the better part of valor, and all...

I'm still going with the jump-jets.

But to take the question as it was asked:

First I'll state my credentials others have so why not.

1. I've flown on all kind of plane (big ones, little ones, 2 seaters, even the ones that have no business near clouds) Military and Civilian.
2. I've seen treadmills... I've even been on one or two.
3. I got peeps that know peeps that have also seen treadmills AND flown on planes.

If you don't feel I'm qualified to answer this question then I sujest you move on to the next post

First I have to make a couple of assumptions here, I tend not to assume but CLL didn't stick around to clarify

Lets assume that the Plane has a endless supply of fuel and because the treadmill is computerized to match the speed of the plane than it has to have a point where it will end (or it would be a runway wouldn't it?) because it a solid belt that on a loop.

Now that that's out of the way, forget about this:



for a minute.

Imagine instead of a plane, you've got a rocket with wheels sitting on that belt. When that rocket fires, it's eventually going to rocket off the end of that belt. Right? At some point will the engines will move enough air to get the plane moving (which will cause the belt to keep pace) the belt will always adjust AFTER the planes speed has increased meaning the plane will move forward. At some point the plane should have enough airflow going over and around the wings to provide lift. If not that belt is going to run out and that plane is gone.

Or maybe not

That's a big azz treadmill.

Countertrey wrote:Well... don't most planes reach V2 at speeds below 150 mph????

Stick to the original question. I'm confused enough.

Don't you need to edit that sig :?: Now that you have your avatar back

Countertrey wrote:

Well, it's about as relevant as you telling us all you were in the Navy as an airdale.

Had YOU read the entire thread, you would have known that was in direct response to another poster's (Skinz74) use of his Naval experience. Apparently, I am the only person not permitted to make such responses in your book. MY evperience is valid. You wish me to accept that YOU have some expertise because you are a pilot. My experience is just as valid as yours. You are definitely barking up the wrong tree. You, your self, stated that your comments had no relevence.

I happen to agree. Genetics do not impart knowledge of physics.

Re-read the question.

Fine. Let's BOTH do it.

A plane is standing on a runway that can move (some sort of band conveyer). So far, so good
The plane moves in one direction, while the conveyer moves in the opposite hmmmm... BOTH are moving... and in OPPOSITE directions
direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite
direction). soooooo... if the PLANE is moving at 150 mph in one direction, then the TREADMILL is moving at 150 mph in the OTHER direction

The question is:Will the plane take off or not?


Well... don't most planes reach V2 at speeds below 150 mph????

Rack one up for the old guy. To be moving at 150 miles per, the plane would have to moving off the conveyor belt. That would require the engine to be delivering thrust enough to balance the influence of the converor belt (150 mph) and another 150 mph to actually be said to be moving at 150 mph.

Let's say, for instance, that in normal circumstances the plane requires thrust that would propel the plane 83 mph before it flew. In the circumstance that the conveyor belt is moving at 150 mph in the other direction, the plane would need thrust enough to move 150 mph just to stay at the same place on the conveyer belt and an additional amount of thrust to drive it to an additional 83 mph, which would create enough movement of wind over the wing to allow the plane to fly. In this case, in order to fly, the plane would reguire thrust enough to drive itself 283 mph
in ordinary circumstances to fly off a conveyor belt going 150 mph in the opposite wasy.

ATV wrote:Answer = Hell No.

Lift, which makes airplanes rise, is generated by air pressure beneath the wings.

Bingo! Thats the answer!

jazzskins wrote:

ATV wrote:Answer = Hell No.

Lift, which makes airplanes rise, is generated by air pressure beneath the wings.

Bingo! Thats the answer!

Nope, it is not

I'm sorry, the conveyor can do whatever the heck it likes, but it isn't stop those jet engines from getting the aircraft moving forward.

Unless the conveyor is also capable of getting the air around the aircraft to move at 150mph in the same direction as the wings are trying to go...

There it is. Conclusive proof that Brits are smarter than Yanks. 100% of them got the answer right.