will it take off?

[MossRoad]

I've seen many a jet not have enough power to overcome a 2" wheel chock. The ground will be tearing up behind them, grass and stuff flying all over the place, and the thing doesn't have enough power to push itself over a piece of 4X4 that has been cut on the diagonal to make triangular chocks. Where's all that force going? Just out in the wind behind it because an 8 ounce piece of wood 2" high is holding it back. You could stick your steel toed workboots under there and hold back a sizable business jet at hard throttle when it is attempting to get moving from a stop. It really doesn't take that much to hold it back. And I'm talking about sizable jets like Falcon 20s that FED-X used in the 80's, not some weeny jet like a Bede-5. So no, I'm not kidding. It takes a LOT to get a plane to move from an initial start and it doesn't take much to hold it back.

 

[BillyP]

I can't get that link to work.

Try YouTube - RC B-52 takeoff, flight and crash.. Egon had an extra http://

 

[MossRoad]

Try YouTube - RC B-52 takeoff, flight and crash.. Egon had an extra http://

Thanks.

Man, the poor person that had all that time into making that thing!

 

[rback33]

I watched that and was thinkin "that aint no B52".... then I realized the link said RC in there.... then it was kinda funny

 

[Egon]

Hey, thanks for gettin things straightened out for me.

Do some checking on You Tube and watch the landings at the old Hong Kong Airport.

 

[joerocker]

Moss,

A wheel chock is like a brake. It's MEANT to keep something from rolling. It will hold back a car too. The MCB isn't a brake, it doesn't keep the plane from moving THROUGH THE AIR.

Why is everyone so obsessed with the wheels and tires? They're ONLY there to hold the plane up and allow it to roll forward to gain airspeed so it's wings can attain lift. Having the ground move underneath has no relevance since the plane is disconnected because the wheels are free to turn. As long as there is nothing to prevent the plane from moving through the air, it will.

 

[rutwad]

what's up with all these formulas? They prove NOTHING!
I can give you a flying bumble bee, but you can't provide a formula to support that.

THE PLANE FLIES!!!

 

[MossRoad]

Moss,

A wheel chock is like a brake. It's MEANT to keep something from rolling. It will hold back a car too. The MCB isn't a brake, it doesn't keep the plane from moving THROUGH THE AIR.

Why is everyone so obsessed with the wheels and tires? They're ONLY there to hold the plane up and allow it to roll forward to gain airspeed so it's wings can attain lift. Having the ground move underneath has no relevance since the plane is disconnected because the wheels are free to turn. As long as there is nothing to prevent the plane from moving through the air, it will.

It won't hold a car back. In fact, the car will jump it with relative ease. The jet will have to apply huge amounts of power to make enough wind to blow it over the chock. A car can go over curbs and an airplane cannot. Where did all that energy go from the airplane? Into the wind. That's the same place the energy will go from a plane sitting on the magic conveyor belt... into the wind.

If there was no resistance, the plane would accellerate to infinity forward while the conveyour accellerated to infinity backwards in the same instance. You have to consider the wheels and the forces that the magic conveyor belt will exert against them.

 

[SPYDERLK]

MossRoad, even a real conveyor built FOR the purpose would do a heck of a job in the short term.
Larry

 

[turnkey4099]

It won't hold a car back. In fact, the car will jump it with relative ease. The jet will have to apply huge amounts of power to make enough wind to blow it over the chock. A car can go over curbs and an airplane cannot. Where did all that energy go from the airplane? Into the wind. That's the same place the energy will go from a plane sitting on the magic conveyor belt... into the wind.

If there was no resistance, the plane would accellerate to infinity forward while the conveyour accellerated to infinity backwards in the same instance. You have to consider the wheels and the forces that the magic conveyor belt will exert against them.

First a jet doesn't move by "making wind", it moves by reaction to moving mass amounts of air backwards.

Your arguments are getting weaker. First you have to show there is enough rolling resistance to keep the plane from moving with the engine at take-off power. Set it on the ground it moves, set it on the conveyor = it will move as the axle friction is all that provides resistance. That is the same resistance that was there when it was on the ground and it just ain't very much.

For the plane to remain still with respect to the air, you have to provide a major amount of resistance somewhere. You haven't done it yet.

Re the jet and chocks - that goes all the way back to the late 40s & 50s. Lots of people claiming you could hold a jet back as long as you never allowed it to move at all. Of course that was a whole bunch of hooey.

I spent 21 years in the AF, granted not directly dealing with planes, but all on flyiing bases. Yes, a jet will jump a chock.

Harry K