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I can't beleive we went through this whole thread and no one mentioned the gription rule. 
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Lee -
My head hurts just reading all of this, but I STILL stand by my last decision.....it depends on the assumptions made in the original statement.
As stated in response #55, ..if the plane isn't moving, neither is the conveyor!!
What am I missing here????Ken W.
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"If you can't fix it right, fix it so no one else can fix it right."Comment
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OK folks try this answer for size:
or
or Google
airplane + "conveyor belt" and read to your hearts content.....Comment
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OK
enough is WAY too much
Yesterday I read a message signed like this:
mpc
Level 5 Engineer - Senior Principal Engineer/Scientist
Aerodynamics, Stability & Control, Flying Qualities, and Simulation
Boeing (formerly McDonnell-Douglas)
Now, today I see at least 20 messages trying to contradict this person, and yet he makes how much to know this stuff, and the rest make how much to make nonesense?
I freekin give up... I was POSITIVE the plane would not move, I am a stubborn swamp yankee by birth, and even I saw the light.
The plane will fly.. period...The voices made me do it.Comment
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Okay, I feel safe replying again. It's amazing how fast this thread grew from when I last logged in...
I was rather tired (late night sessions in the simulators knocking me totally off schedule) when I posted that; later I realized it looks like I'm trying to say "I'm the world's expert on this so listen to me and shut up" which wasn't my intent. I would have edited it out but others had already quoted it. I apologize to anybody that I offended or annoyed.Yesterday I read a message signed like this:
mpc
Level 5 Engineer - Senior Principal Engineer/Scientist
Aerodynamics, Stability & Control, Flying Qualities, and Simulation
Boeing (formerly McDonnell-Douglas)
How much do I make? Not enough. haha.Now, today I see at least 20 messages trying to contradict this person, and yet he makes how much to know this stuff, and the rest make how much to make nonesense?
Niki - for that El-Al crash, the circumstances were more than just dual engine failure. One engine actually broke off the wing (due to corroded mounting pins) while the engine was running fine... it tore up part of the wind AND smashed into the engine next to it knocking it off the aircraft too. This happened shortly after takeoff. The flight crew was able turn around and start flying back to the airport; as they turned onto final approach though their airspeed got too low for the torn-up wing and it stalled. That loss of lift caused the loss of control. The airplane did stay airborn though on only 2 working engines for a while.
There's a rather informative website, with a somewhat morbid title, that collects this accident type of stuff. I actually make new folks in my group read some of this to remind them of how serious their jobs can be:
It does have pop-up adds though, fair warning. Many of the pics are of maintenance goof-ups... guys forgetting to set the parking brake and finding the airplane rolled into a ditch the next morning; etc. It's not all sick.
mpcComment
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Russian Wolf, I salute you. Never would I have expected this kind of reaction to a simple question. This might be a record. At least it is probably a record for the total number of hours of thought and calculation devoted to one thread.
I read about 8 pages of replies and some of you can come and work for me anytime. Others, nope.
Anyway, I say the plane flies provided (as someone else pointed out) the bearings can handle twice the normal speed and the engines can produce sufficient thrust to overcome the extra drag from the faster-turning wheels.
I don't expect this to be final, but I'd bet a week's pay on it.AndrewComment
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I don't think the question can be answered as stated. It all comes down to how "speed" is defined.
Science defines speed as distance traveled over time (such as mph). x=vt (or v=x/t)
One can argue it won't take off because of the conveyer. If you are on a treadmill set at 5 mph you'll have to run to 'stay in place' in relation to your surrounding. But you actually ARE moving your legs at 5 mph because your distance traveled is based upon the length (distance) of conveyour belt passing under your feet.
But if the conveyour is moving at 5mph and you at 10 mph, your moving at 5mph in relations to your surroundings.
So the assumption is made on how the airplane's speed is being measured. By the distance of converyour traveled (or wheel speed)? in which case the plane can't take off. Or by the air speed (amount of air passing around the wings)? in which case it will take off.
Either way the question doesn't state WHAT the airplane's speed is in reference to, conveyour or surroundings. Therefore everyone's right depending upon which assumption they made.Eric
Be Kind OnlineComment
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The question is a theoretical question and should be answered that way IMO.
The question is asking simply "will takeoff or not" considering only one factor; The conveyer is rotating at the plane speed to the opposite direction.
Actually, if it was B-707 or B-747 the tires would blow before it lifts off. The tire speed limit of both planes is 225 MPH (Goodyear). Usually, a fully loaded 707 or 747 will liftoff around (if my memory is not failing me) 150~160 Knots (Nautical mile/hour) that are around 180 MPH and if the conveyer is rotating at the opposite direction at the same speed......
About speeds, normally, the speeds that are generally known are MPH or Km/H (on the other side of the pond). Those who are in maritime, know another speed; Knot (1 Knot = 1.15 MPH.)
In aviation, all the speeds are represented in Knots (except the tire limit speed) but, there are many "speeds" like:
GS - Ground Speed
TAS - True Air Speed
IAS - Indicated Air Speed
CAS -Calibrated Air Speed
EAS - Equivalent Air Speed
Maybe I forgot a few more
The most important speed for the pilot is the IAS that measure the actual MASS of air acting on the wing for the Lift production (and its different at see level and at 41,000 Feet).
Too low an IAS, and the airplane stalls and turns to a falling stone and the gravity lows of Newton will take care for the rest...
Too high IAS, will break the plane and it will come down in a form of (big) potato chips.
As Russianwolf said, it's a "trick" question just to test us if we know that there is no connection between the engine and the tires, and it should be answered as a "trick" or very theoretical question (at least I don't know an airport that the runway is a conveyer rotating backward).
Mpc
Thanks, I did not know all the facts exept that they had " 2 Engine Sepatation".
The same happend to a B-727 that lost an engine at takeoff at Lapaz airport and turn (steep) to land. (Lapaz airport is at 14,000 feet and sorounded by mountains).
nikiComment
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Oh forgedaboutit!
The plane will crash!!!!!!!!!!!!!!!!!!!!!!!!!!Comment
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Okay, this is a scenario I haven't seen. What if it's a Stanley plane?
LeeComment
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No stipulations as to a number.
If it was a sharp plane, I think it would take off and fly, unless I was using it. In this case it would sit and rust.
I do have one that actually moves though. Typical block plane. This would create belt movement, but after a couple inches, I'd give out and grab a file. How far will a file fly?
LeeComment
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