why cant aeroplanes reverse????

Answer 1

Do it all the time. We have thrust reversers on the engines which are normally used during landing to help slow down. But I fly an executive Boeing 727 to many airports that don't have a tug big enough to push us back so we have to reverse out of parking spaces on occasion. We'd rather not have to do that though as it kicks up a bunch of crud from the ramp sometimes that can be injested into the intake.

Answer 2

As you read in he other answers jet aircraft in some cases can use reverse thrust to back up.

I've read that studies are going on to develop a drive system for the wheels of future airliners that would save fuel by allowing the pilot to start the engines only right before take off.

Richard Branson the president and owner of Virgin Altantic began experimental operations in London where fuel is saved by towing aircraft all the way out to a holding area near the take off point. Saving all the fuel the plane would otherwise waste just moving to that area.
I have not read anything yet about the results of that study.

Answer 3

On the ground, most turboprops and commercial jets can, in fact. That facility, known as reverse thrust, is usually used for braking after landing.
Reversing at the stand is not normally permitted because a) the crew can't see where they're going, and, b) the blast can cause considerable damage to equipment & personnel on the ground, as well as kicking up all sorts of cr ap which can be sucked into the engines.

In the air, aircraft rely on forward movement creating the passage of air over the wing to provide lift, except those that can rely solely on engine thrust, vide the Harrier.

Answer 4

Some aircraft CAN reverse, using the thrust reverser, which redirect most of the jet flow towards the front. Granted, this is not a very high % of the normal forward thrust that gets effectively redirected, and for high bypass turbofan, only the low pressure flow (which still accounts from most of the thrust while in the normal operation mode) is diverted. Propeller airplane can also use variable pitch to achieve reverse motion, if they have variable pitch propeller (small single engine piston aircraft usually do not have variable pitch propeller)

Backing up a plane is a delicate operation that must be monitored by ground personel, as the pilots do not see where they are going.

Answer 5

On the ground Aeroplanes can use the reverse thrust to reverse out of the hanger or parking bay. It works out cheaper and easier for it to be pulled out onto the tarmac to get the plane ready for take of if you mean reverse in flight the plane would stall and do a fall out of the sky.

Answer 6

I think everyone's missing the point here. Aeroplanes only stay in the air because of the movement of the air passing over the wings - providing there is enough volume of air passing in the right direction (ie. front to back!). The shape of the wing allows the air to lift the aircraft upwards. If you were to put the engines into reverse it would only slow the plane down reducing the "lift" and eventually "stalling" it into a dive. You would never be able to get it to go backwards - only if it were on the ground! Harriers, etc are different - they use massive amounts of thrust to hover and manoevre backwards.

Answer 7

Some of them can reverse.

Harriers can fully reverse their exhaust vector nozzles and the aeroplane will fly backwards. Its wings are shaped to allow it to work.

Most large turboprops (e.g. the RAF Hurcules- it can taxi backwards whatever afikoff says, I've seen it) can reverse the pitch of their propellors to enable them to slow down when landing and also drive slowly backwards on the ground.

All jets can divert a small proportion of their exhaust forwards to enable braking when landing (reverse thrust) but this is never used in the air.

Aeroplane wings are shaped so they're thicker at the front (leading edge) than the back. This "aerofoil" shape is what gives them their lift. If the aeroplane flew backwards the wing wouldn't so efficient so "lift" wouldn't be guaranteed.

All helicopters can fly backwards.

Answer 8

Most can't due to the fact that the powerplant(s) only provide forward thrust. In some cases aircraft are equipped with propellers that can change the angle of the blades and provide reverse thrust. As people have mentioned some jet aircraft also use thrust reversers which deflect the air and exhaust gases (thrust) in the opposite direction. This is mainly used to slow an aircraft down when landing on a shorter runway.

Answer 9

Aeroplanes can reverse. Those with jet engines can use the reverse thrust mechanism. However Its noisy and creates too much dust so it is genrally more efficient to use pushback tugs :-).

Answer 10

Some can. The Hercules can reverse direction on the engines and pull the aircraft back (used for tactical landings and parking on the pan).Techically, the Tornado (with it's reverse thrust buckets) could too.

Obviously, it couldn't fly backwards, but this is very useful on the ground.

have a look...
http://en.wikipedia.org/wiki/Reverse_thrust