Threads

"As a pilot, I am not here to debate that the aircraft will take off, but the Mythbusters did not have an accurate test.

As shown in the episode, the aircraft started moving foreward, before the belt was at the same speed, there by off setting the speed of the plane and the belt. The plane continued to accelerate faster than the belt and took off.

The best way for this myth to be tested, would be to hold the plane in place, accelerate the belt to the takeoff speed, and then let the plane loose at full throttle.*****PLEASE MYTHBUSTERS, REVISIT THIS MYTH AND USE THIS RECOMMEND TEST FROM A RATED PILOT!

Another way of looking at this myth would be a seaplane on a river. The seaplane will be carried with the flow downstream, until the engine can produce enough thrust to over come the pull, and it will sit there, and once it overcomes the flow, it will accelerate and take off.

PLEASE REVISIT THIS MYTH."

"Aaaahhh!

I didn't see your proposed experiment until now and I agree; under most of these open-ended conditions, flight is possible.

There are a few propositions under these terms, however, that, as a matter of fairness, should be considered:

If the plane is capable of infinite thrust and the conveyer is limited to a set maximum, then the plane will always get airborne and the myth is true.

If the plane has unlimited thrust potential and the conveyer also has infinite potential, then the myth is plausible but impossible to research.

If the plane has limited thrust and the conveyer is also limited on potential, then the myth is both plausible and possible to research. It really comes down to how much bigger one item is over the other and your hypothesis hints that I'm allowed to get a bigger, more powerful conveyer.

If the plane has a set limit on thrust and the conveyer has infinite potential, then the plane will never fly. Eventually, the wheels will be unable ward off all of the drag force and the myth is busted.

Under these sets of values, You're right at one end of the scale and I'm right at the other.

If we're talking abount an all-or-nothing proposition where plausible is not an acceptable outcome, then, under the Scientific Method of Investigation, the myth must be busted because one set of variables exist that negate the hypothesis.

Either way, I appreciate the friendly sparring. My hats off to a worthy opponent!"

"miles per hour (mph) = knots * 1.15
Take your (ground) speed in knots and multiply it by 1.15 to get your (ground) speed in miles per hour.

example: 300 x 1.15 = 345 mph

When you match airspeed of 25 knots to a vehicle doing 25 miles per hour.............DO YOUR MATH.........IT'S NOT THE SAME!!!!
If they had converted miles per hour to match exactly the (knots) airspeed of the plane, there might have been a different result.....but because they did not match the speed correctly............you can't call it busted.............DO IT AGAIN CORRECTLY
"

"Think about it in its extreme. Say the airplane has a maximum capable speed of 100 mph at full power. It’s on a belt that accelerates to 100 mph backward. At this point the airplane is stationary on the belt and being moved backward in relation to the air at 100 mph. It now spins the propeller at full power and accelerates to its maximum speed of 100 mph. Its wheels are going 100 and the thrust is moving it at 100 in relation to the BELT, BUT it is now stationary in relation to the surrounding air and ground, so its airspeed is 0. It will not lift off because it is not producing lift."

"From one possible perspective I ask: How is "the conveyor belt (tarp) at 20 mph" and "ZERO GROUND SPEED" "THE SAME SPEED"? 20 <> 0. "AT THE SAME SPEED" is not sufficiently unambiguous to conclude that it must mean only "WHATEVER AIRSPEED IS NECESSARY TO MAINTAIN ZERO GROUND SPEED". To my reading, zero ground speed does not seem like the same speed as 20 mph groundspeed. It's a language parsing problem, not a physics problem."