Will the plane take-off?
Thread Starter
Joined: Jan 2004
Posts: 187
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From: London
Will the plane take-off?
Can someone please explain this:
A plane is standing on a runway that is made of a large conveyor belt. The plane fires up its engines, but as it moves forward, the conveyor belt senses the speed of the plane's wheels and moves at exactly the same speed in the opposite direction. Can the plane take off?
Silly I know..........but still
A plane is standing on a runway that is made of a large conveyor belt. The plane fires up its engines, but as it moves forward, the conveyor belt senses the speed of the plane's wheels and moves at exactly the same speed in the opposite direction. Can the plane take off?
Silly I know..........but still
A Runyonesque Character
Joined: Apr 2004
Posts: 1,209
Likes: 2
From: The South of France ... Not
It will take off – backwards. It will hover in ground effect for a moment, then stall and crash back on the runway. The impact on the moving belt will collapse the undercarriage and the aircraft will travel backwards on the decelerating belt until it comes to a stop alongside the waiting fire tenders.
Believe me – I’ve seen it happen many times.
Believe me – I’ve seen it happen many times.
Joined: Jan 2007
Posts: 82
Likes: 0
From: Milton Keynes
It is in fact a trick question.
It assumes the reader believes that the speed of the wheels is in anyway related to an aircraft's ability to move forward. Of course it isn't, its the thrust generated by the engines that move an aircraft forward and has nothing to do with the speed the wheels are rotating (providing the brakes are not applied of course).
The aircraft will accelerate in a forward direction and will take off normally.
The fact that the runway/conveyor is trying to maintain a speed proportional to the speed of the wheels albeit in the opposite direction is immaterial. all that this means is that the conveyor belt will accelerate exponentially.
Providing the wheels can rotate fast enough and not disintegrate then it will have little or no effect. If the take off speed was 220 Kts then at take off the conveyor will be running at 220 Kts in the opposite direction and the wheels will be running at 440 kts.
Hope that helps.
It assumes the reader believes that the speed of the wheels is in anyway related to an aircraft's ability to move forward. Of course it isn't, its the thrust generated by the engines that move an aircraft forward and has nothing to do with the speed the wheels are rotating (providing the brakes are not applied of course).
The aircraft will accelerate in a forward direction and will take off normally.
The fact that the runway/conveyor is trying to maintain a speed proportional to the speed of the wheels albeit in the opposite direction is immaterial. all that this means is that the conveyor belt will accelerate exponentially.
Providing the wheels can rotate fast enough and not disintegrate then it will have little or no effect. If the take off speed was 220 Kts then at take off the conveyor will be running at 220 Kts in the opposite direction and the wheels will be running at 440 kts.
Hope that helps.
