A beginner's doubt on jet engines

10 Points to Bob, who got it first

Merry Christmas everyone.


"Cockpit Colin" wrote in message
...
For what it's worth, a 757 at ground idle produces around 3000 pounds
thrust
per engine - you can back them using the reversers, but you can't go full
power as the re-ingest the exhaust gasses.

And when you're backing you must always use forward thrust to stop, and
not
the brakes - anyone guess why?


"Ramapriya" wrote in message
oups.com...
I know that a car's engine needs to be mated to the transmission for
propulsion. This I know isn't the case with an aircraft with a jet
engine; if the engine is turned on without the brakes applied, the jet
of air leaving the engine will hurl the craft forward.

My doubt is, why does this forward motion effect not occur during
push-back, when the engines are normally turned on? Is it because at
low revs the engine would lack the punch to initiate the forward motion
of a heavy aircraft? If not, I'd imagine the push-back becomes a bit of
a tiresome affair by the time it's over...

Sorry if this is infuriatingly elementary, but I need to ask somewhere


Ramapriya