Let's say you had a giant treadmill with an airplane on it

[PCL_128]

I don't have to think too hard on this one. It's quite simple. No airflow, no airspeed. No airspeed, no takeoff.

And I just lost a lot of confidence in the FedEx screening process.

 

[fartknocker]

And I just lost a lot of confidence in the FedEx screening process.

This was one of the interview questions. I had my treadmill, and model airplane all ready to go. I proved it right there in the interview. They were amazed!!

 

[FlyinScotsman]

Maybe I am an idiot, but I think it sounds fairly simple.

I run on treadmill I don't go anywhere.

I don't produce any relative wind. ie wind in my face.

I learned very early on that I needed some airflow over the wing to make it work, measured by the pitot tube, which would be reading zero. So no lift.

My airplane on a tread mill still isn't going anywhere, just like me when I run.

So how about you geniuses that seem to have this all figured out please explain.

Because, like I said I might be an idiot, but someone will have to show me. Maybe with whiteboard or a powerpoint presentation

 

[fartknocker]

FlyinScotsman,

Yep, me too.

 

[FlyinScotsman]

maybe, we need one of those PFT geniuses or one of those who log PIC time as an FO.

I bet they have got this all figured out!!

 

[YourPilotFriend]

There are to different thought processes going on in this thread.
1. The plane remains stationary and doesn't take off
2. The plane provides enough force to accelerate down the belt and take off.

I think the way the question is worded, it pertains to #1. However, based on a certain set of conditions #2 is possible, however the question is incomplete to answer that.

 

[fartknocker]

YourPilotFriend,

I read the question to mean that the plane was stationary. Based on this, the plane would not take off.

 

[COOPERVANE]

Picture yourself on the treadmill wearing rollerskates. You hold a rope in your hand that is secured to a building far in front of you. The treadmill is moving at 5 mph and you pull on the rope. Would you move forward? Yeeeeeesssss!What if you pulled at 60 kts? Think of the propeller thrust as the rope as you pull. You would have a helluva wheel speed at takoff though!!

12 shots of tequila

 

[FlyinScotsman]

I thought I would dust off this old gem to kill the PIC thread.

Let's say you had a giant treadmill with an airplane on it.

As you add power and begin to move for the takoff roll, the treadmill speeds up and keeps the plane in the same relative position. As the plane goes faster, the treadmill speeds up, always maintaining the aircraft's relative position.

Would you ever be able to take off?

GO!!

I can't believe I am getting sucked into this.


As stated above the airplane stays on the treadmill and remains in the "same relative position" So, I assume, that the treadmill is not allowing the airplane to get any friction and actually move forward.

Once again......... no movement......no airflow..........no flight.


I am such a sucker, I know........I know..........

 

[Flyer1015]

There are to different thought processes going on in this thread.
1. The plane remains stationary and doesn't take off
2. The plane provides enough force to accelerate down the belt and take off.

I think the way the question is worded, it pertains to #1. However, based on a certain set of conditions #2 is possible, however the question is incomplete to answer that.

EXACTLY!!!


I think everyone is right... it depends which case you're referring to.

Case #1 or Case #2