No, no more than it hurts if it’s going in the other direction. :dubious:
Unless Monty Hall shows you the donkey behind door number 1, and offers to let you swap your door (#2) for Door #3…
The theoretical case has already been answered to my satisfaction, if not to everyone’s. To me, the question gets interesting when trying to figure out what the practical limitations are.
In addition to the speed limitation imposed by the tires, I get the impression that rolling vehicles become more difficult to control as their speed increases. Any variance from your desired line of travel will carry you off that line a lot faster at 100 mph than it would at 10. I’ve always wondered if the plane would reach a controlability threshold at some point, where you couldn’t make steering inputs fast and precise enough to stay on the runway.
It does matter if the runway first reaches a constant speed with the plane standing still relative to a finite runway (brakes on, wheel chocks, or the acceleration is so gradual it doesn’t overcome the friction of the wheel bearings). Which is the case with a real life moving runway: an aircraft carrier. Consider especially a WWII carrier flying off its a/c without using the catapults*. The carrier would take minutes or hours to accelerate to launch speed with the plane standing still relative to the deck. Say it wasn’t windy to simplify visualizing. The plane’s ability to get airborne in the space available would obviously depend which way the carrier was steaming compared to which way the plane was trying to take off. Or again more realistically in low wind with a slow carrier (like an escort carrier) the plane might end up in the water forward of the ship, which is why smaller escort carriers got more in the habit of using their catapults as time went on. A fast carrier had plenty of speed to get WWII carrier planes airborne without using the slow to reset catapults, even in fairly light wind, as long as the leading planes could be arranged fairly far aft to start their takeoff run.
In the Mythbusters case the conveyor is accelerating rapidly with plane powered up already. Yet still the amount of ‘conveyor’ passing under the plane’s wheels will be greater with the truck pulling it in the opposite direction to the plane’s take off run than if it’s pulling the same direction And amount of runway passing under the wheels before takeoff is the key element in the closest real life analog to the situation.
*US WWII fast carriers had catapults but often didn’t use them; Japanese carriers generally didn’t have catapults. Same would apply with catapults actually, but I think it’s easier to make the comparison with fly off without the possibly confusing addition of a catapult to the situation.
Treadmill!
Slowly I turned. Step by step, inch by inch…
Ha! I knew it! Once, in 1960, for about 20 minutes, I fell for the same scam.
Of course, in 1960, the Internet ran on punch cards, so you had to take some extra steps.
Still no. The airplane will take off when the velocity of the air over the wings produces enough lift to exceed its weight. It doesn’t matter how you produce that relative airspeed, and it certainly doesn’t matter what the wheels are sitting on or what that surface is doing.
I really would have hoped the entire Internet would have understood that by now.
I believe that you and I are the only two, Elvis. Bernoulli is dead.
Does it matter if the runway has a gold fringe?
They put an R/C airplane on a roll of paper and pulled the paper. The airplane moved much faster than the paper and took off.
If the runway gets up to and above the stall speed of the airplane, with the airplane still, relative to the runway, the airplane will take off with the brakes still on.
I believe that was the scenario Corry El was talking about.
Been many years since I saw that episode, but I’m pretty sure they used a real plane as well.
Perhaps so, I recall a truck pulling the roll of material. It wasn’t paper with the real airplane.
I believe that the concept is that the aircraft and the conveyor belt are moving at the same speed. The aircraft does not move in relation to a fixed point off the conveyor belt. There will be no air movement relative to the wings.
The runways around here are all moving at close to 1000 MPH. In fact, they circle the Earth once a day!!!
Nifty!
Cool!
What I said is definitely true. It must be a matter of you not reading or considering it carefully enough. In the real life case of a moving runway, an aircraft carrier, the key consideration is how much ‘runway’ passes under the planes wheels before the relative wind speed over the wings reaches flight speed. In the hypothetical conveyor or Mythbusters quasi ‘conveyor’ demonstration case that doesn’t matter.
IOW any plane that could get in the air from a stationary runway could take off from an infinitely long carrier flight deck with the plane taking off forward and the ship steaming astern. But on a real finite carrier deck the plane would use up more deck to get to flying speed the lower the sum of the carrier’s and the wind’s speed (assuming the carrier steaming into the wind). And if the amount of deck required exceeded that available, the plane would go into the water.
Nobody would ever consider trying to fly off WWII carrier planes forward with the ship steaming astern, nor with the ship at anchor unless it was a exceptionally windy. It wasn’t because they never watched Mythbusters, it was because it wouldn’t work. Yet with the ship steaming fast ahead it was generally practical even in relatively light wind, and catapults weren’t generally used till carrier plane minimum flying speeds rose (as for jets for example) post WWII. But the speed and direction relative to the takeoff direction of the ‘moving runway’ of an a/c carrier absolutely mattered (and matters today with catapults virtually always used). The artificial hypothetical of an endless conveyor tends to obscure that practical reality.
But what if the plane is in orbit, and the conveyor belt is on a space station?
Then the aircraft would be in a vacuum and there would be no airflow over the wing. It would be something wicked.