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E120
9th Mar 2001, 15:06
A question I run into concerning all types of aircaft; When you're doing a static takeoff, applying full takeoff power without moving. Do the brakes get hot at this time?

HPSOV
9th Mar 2001, 17:33
Nah mate,
Brakes only get hot when there is friction, and friction is caused by motion!
If the aircraft isn't moving there is no friciton, so hence no heat is created!!

E120
9th Mar 2001, 22:05
OK, that's what I thought. Now; were does all that energie do than?

DreamCatcher
9th Mar 2001, 22:47
Is this a wind-up?

Virtually all the energy (presume you're talking about the engine output, and not the pilot's feet on the brakes!) is thrust, chucking cubic metres of air backwards. The plane can't react in a forward direction 'cos the brakes are on.

Some energy will be absorbed in a vibrating airframe and passengers' teeth!

Hope that's OK. :)

PS - your profile says you're a pilot?????

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If you're not on the edge, then you're taking up too much space.

[This message has been edited by DreamCatcher (edited 09 March 2001).]

BigJETS
12th Mar 2001, 02:13
There is a transfer of energy going on at that moment. But the product of the energy, HEAT, is not occuring at the brakes, its occuring within the "engine" which provides power to the "grip" Mechanical stress is going on at the grip which at the moment is ONE part. It will also be occuring in every link between the "engine" and the "grip". There will be minute heat associated with this stress undetectable until one part becomes two under load (friction).

Lucifer
12th Mar 2001, 13:42
In theory, the energy (due to equal and opposite reation) is going to the earth, thus rotating the earth (and moving masses of air as well). So all the Fast Jets spooling up stationary are messing up our orbit! The effect is pretty much insignificant though. (Ditto when you brake after landing)