RobS
Super Member
But is it HST or GST???
Most excellent work, BTW!
Most excellent work, BTW!
It will not take off but it will fly!
- Thread starter NorthwestBlue
- Start date
Jimbrown
Veteran Member
sappaw
New member
Well Guys, look at it this way, suppose the conveyor belt is moving backwards at 60 mph relative to a fixed point on the ground. The airplane, with the engine off, is then also moving backward at 60 mph relative to a fixed point on the gound. The pilot starts the engine and opens the throttle to 2000rpm, The airplane accelerate relative to a point on the conveyor belt to 30 mph but is still moving backward relative to a fixed point on the ground at 30mph. The rpm is increased to 2300rpm and the airplane accelerates to 60mph relative to a point on the belt. The airplane in not moving relative to the fixed point on the ground. At this point the frustrated pilot open the throttle all the way to 3000rpm an accelerates to 100mph relative to a point on the belt. But the belt is also accelerated to 100mph in the opposite direction. So the airplane will not move relative to a fixed point on the ground.
If there is no wind blowing, there will be no air moving over the wings to generate lift because the airplane must be moving relative to a fixed point on the ground for air to be moving accross the wing so the airplane cannot takeoff. If the airplane had enough power to go mach 2 relative to the belt and the belt always matched the speed of the airplane in the opposite direction then the airplane wound not move relative to a fixed point on the ground, there would be no relative wind over the wing, no lift gererated and the airplane would not fly.
Welcome to the The Theory of Relativity.
If there is no wind blowing, there will be no air moving over the wings to generate lift because the airplane must be moving relative to a fixed point on the ground for air to be moving accross the wing so the airplane cannot takeoff. If the airplane had enough power to go mach 2 relative to the belt and the belt always matched the speed of the airplane in the opposite direction then the airplane wound not move relative to a fixed point on the ground, there would be no relative wind over the wing, no lift gererated and the airplane would not fly.
Welcome to the The Theory of Relativity.
JoeinTX
Platinum Member
Sappaw.......I can't thank you enough.
Gaining flight is not about RPM or engine size or wheel speed.............IT's ABOUT RELATIVE GROUND SPEED.
If the airplane is sitting on a conveyor that exactly and immediately meets and counteracts all of the aircraft's attempts at ground speed.........then our plane goes NOWHERE.
It's so simple and easy.
Until you have enough wind passing over the wing, and the resulting air pressure changes which can pull the wing up, you are just sitting on the ground.
I know Boortz brings this up all of the time, but, it's a load of baloney.
If your car is sitting on the same conveyor belt, which matches and counteracts all wheel motion........you don't move. No wind motion will you feel.
Thus, no fixed-wing aircraft can gain flight in this scenario.
Done...........over..........answered.
Gaining flight is not about RPM or engine size or wheel speed.............IT's ABOUT RELATIVE GROUND SPEED.
If the airplane is sitting on a conveyor that exactly and immediately meets and counteracts all of the aircraft's attempts at ground speed.........then our plane goes NOWHERE.
It's so simple and easy.
Until you have enough wind passing over the wing, and the resulting air pressure changes which can pull the wing up, you are just sitting on the ground.
I know Boortz brings this up all of the time, but, it's a load of baloney.
If your car is sitting on the same conveyor belt, which matches and counteracts all wheel motion........you don't move. No wind motion will you feel.
Thus, no fixed-wing aircraft can gain flight in this scenario.
Done...........over..........answered.
the_sandman_454
Silver Member
An airplane's tires freewheel. Even if we count friction, just about every airplane, with the exception of the tractor plane in the original post, the wheels have low enough frictional and rotational forces to allow the plane to still take off. If the pilot can't seem to make it happen, cuff him in the back of the head and say the phrase "hey idiot, release the brakes"...
To test this, you'll need three things. A pair of rollerblades, a friend, and a treadmill. Your friend represents the engine of the plane. Have your friend stand somewhere other than the treadmill (i.e. off to the side). Start the treadmill, and have your friend hold you in position. Then have your friend advance the throttle on you (i.e. start pushing you forward to simulate the thrust an airplane's engine produces). You will not stay in the same place on the treadmill, even if you speed the treadmill up relative to yourself, you will still move relative to the ground, so you achieve lift (assuming a long enough treadmill, and a strong enough friend)...
An automobile or a tractor on the other hand, are driven by the wheels rather than an engine producing thrust, so therefore, these types of vehicles would have no ground speed relative to the earth or the treadmill.
Or you could go with the Harrier AV8, or the F35 joint strike fighter in development, and not bother with a runway at all.
That airplane in the original post looks like it's flying backwards though. I envision it as a twin engine pusher machine, where the propellers are in the back, with a canard in the front. Almost looks like some of the Rutan designs, except there's a tractor built into it...
To test this, you'll need three things. A pair of rollerblades, a friend, and a treadmill. Your friend represents the engine of the plane. Have your friend stand somewhere other than the treadmill (i.e. off to the side). Start the treadmill, and have your friend hold you in position. Then have your friend advance the throttle on you (i.e. start pushing you forward to simulate the thrust an airplane's engine produces). You will not stay in the same place on the treadmill, even if you speed the treadmill up relative to yourself, you will still move relative to the ground, so you achieve lift (assuming a long enough treadmill, and a strong enough friend)...
An automobile or a tractor on the other hand, are driven by the wheels rather than an engine producing thrust, so therefore, these types of vehicles would have no ground speed relative to the earth or the treadmill.
Or you could go with the Harrier AV8, or the F35 joint strike fighter in development, and not bother with a runway at all.
That airplane in the original post looks like it's flying backwards though. I envision it as a twin engine pusher machine, where the propellers are in the back, with a canard in the front. Almost looks like some of the Rutan designs, except there's a tractor built into it...
daTeacha
Veteran Member
I thought the original thread died around post number 800 or so, but it has been reincarnated in this oldie a slightly revised title and some new readership. You guys who are late to this party need to look up the older thread and spend about 3 days reading all the posts. 
MadDogDriver
Gold Member
Go Navy!
tallyho8
Elite Member
- Joined
- Aug 1, 2004
- Messages
- 4,998
- Tractor
- Kubota L4400, Kubota ZD326
I can only repeat what I said in my last thread. (Very unscientific)https://beta.tractorbynet.net/forums/index.php?posts/1102128/
daTeacha
Veteran Member
MadDogDriver said:
Can you even begin to comprehend the G forces that guy is working with!? You can see what appears to be a practice bomb to the right of the plane, unless that's some kind of rocket takeoff assist canister. Condensation like that doesn't usually occur until near the speed of sound. I don't konw that I would be flying that fast that close to the deck.
Fantastic pic! Can you give us any details?