Why don't planes have reverse gear

Question

they have to be tugged out onto the runway before take-off. why is it so? can't they push backwards themselves?

Answer 1

i believe the c-17 and a couple of the russian cargo planes can move backwards.

edit: what's with the thumbs down i've seen them on tv do it.

Answer 2

Wow! What a variety of answers, correct and incorrect.  Here is a correct answer, and you can compare it with the others to make a decision:

Airplanes do not have to be "tugged out to the runway."  All airplanes, large and small, can taxi out for takeoff under their own power.

Most propeller driven transport airplanes (though very few light airplanes) have reversible propellersthat can be used to slow down after landing and also for backing up.  Some propeller airplanes are backed up under their own power quite often.

I once backed a DC-6 into a hangar using reverse propellers, but it was a sweaty job, and I was glad I had about nine guys watching out for me.  The main problems with reverse power are (a) you can't see where the dickens you are going, and need lots of people on the ground to give you hand signals, and (b) you stir up tons of dirt and debris, which is not good for the airplane, the people standing around, and the environment in general.

Many jet airliners and cargo planes also have reverse thrust, and in some cases it CAN be used to back up, but in most companies it is forbidden by company policy, for the reasons given.

So in that sense, airplanes DO have reverse gear, but it isn't called that.  And it is usually used only for slowing down after landing, and not for moving backward on the ground.  In most operations, the tugs only push airplanes back from the gate until they are in the clear and can taxi under their own power.

Answer 3

Planes dont have wing mirrors to see whats behind them... :P

Answer 4

I don't know much about planes,

so whatever i say, i have heard about it but i am not sure,

When a plane is landing, there is reverse throttle, i dont know if that is different from reverse gear but i have heard that reverse throttle is applied.

I think i have seen planes go backwards to taxi of properly to the runway,

i think they can push themselves backwards.

Answer 5

They have, silly!!!

Answer 6

Because the cost and weight to be able to move backwards would just mean they'd use more fuel in regular flight. So it's just more cost effective to use a tractor.

Answer 7

You can use reverse thrust for powerbacks. This is often done with the DC-9/MD-80 series of aircraft. You could do it with any of the Boeing aircraft with the underwing engine setup, but the possibility of FOD would be much greater. I've never seen it done on a Boeing.

With turboprops you can put the props into reverse pitch. I've made a 3 point turn and backed up the last 6 feet in a Twin Otter once in order to get full length out of a short, narrow runway with no parallel taxiway.

Answer 8

turbine engines only can push air one direction, they have something called a reverse thruster witch is only a deflector at the rear of the turbine to change the air flow to the sides to add drag when on the groundd at landing

Answer 9

Imagine it would be slightly awkward to reverse a plane.

Why don't snails fly? It takes them a life time to crawl everywhere!

Answer 10

the MD-80 series used to power-back. But it was only those planes because the engines are mounted up high enough that objects or people wouldn't get sucked in. This also wastes gas and can be dangerous around busy airports. So thats why they usually don't. If you see it happening, take a pic.

Answer 11

Most large commercial planes are just too large and expensive to risk reversing them at airports if they could. The potential to damage numerous planes is there. In short it`s just much safer and cost effective.

Answer 12

       Most jet-liners have thrust reversers which are used for braking after landing.  If they were to be used to back away from the terminal, they would blow the terminal away.

Answer 13

BECAUSE THEY DON'T HAVE BACKUP LIGHTS ?!?!  lol

Answer 14

there would be no point. they cant see where they are going.

Answer 15

As many of the previous answers state, planes could power themselves backwards.  They don't have a reverse gear because the wheels are not linked to the propulsion of the aircraft.  Either the engine or the propellers are used to move.  It would also be dangerous to reverse an aircraft with the engines due to blast from the engines/props and the fact that the pilot wouldn't be able to see where he's going, or what's coming toward him.

Answer 16

They dont need it. They have a tug 2 push them back.

Answer 17

Most commercial aircraft have reverse thrust to help when landing, this could be used to move the aircraft backwards and some propeller driven aircraft will use this to assist in maneuvering at some airports. If you try this with jets the hot exhaust is blown forward and goes in the air intake, causing rapid engine overheating. That's why reverse thrust is not used to finally stop the aircraft on the runway

Answer 18

Your question has already been answered, but I just have to add something.

http://www.youtube.com/watch?v=ID3jfc39x...

http://www.youtube.com/watch?v=DZSs_Fmyv...

Aviation Geeks will usually admit there is something dangerously exciting about watching an large jet that moves tens of thousands of pounds at hundreds of miles an hour, divert that thrust and power with the clamshells/bucket reversers in order to back up a hundred or so feet.

Answer 19

Planes have jet engines en brakes but no gearbox

Answer 20

Planes don't have ANY gears!!

Answer 21

Right. all turboprop planes can move themselves backwards, and frequently do. Some jets such as the MD-80 and Dc-9 also can, but do so rarely. Most jets cannot use reverse thrust below 60 knots because it damages the engines. Aircraft with old style bucket reversers do not suffer this because they simply deflect the thrust in the opposite direction.

Answer 22

I believe planes have a reverse gear.

Answer 23

Many airplanes are capable of backing up under their own power, although it is rarely done these days.  One reason is that it can be dangerous.  The pilots cannot see behind them.  In some planes, the pilots can barely see the wing tips, if at all.  

Another reason is that doing this causes a lot of debris and dust, on the ramp, to be blown at the terminal and ground crew standing around.  

One other reason is that if the pilots are backing up and kit the breaks too hard, the nose could raise up in the air.  A captain at an airline I once worked at was backing up, at the request of the maintenance department (they were too lazy to get a tug), he hit the brakes too hard and the tail of the plane hit the ground.

It is done, however, occasionally.  A few months ago, I saw an MD-80 backup because a few tugs were broken down.

Answer 24

Because  though Jet engines have both Forward and reverse thrust it would be impossible to operate a reverse thrust without slamming into a building while on the ground...

Answer 25

Some jet aircraft have deflectors that direct the exhaust forwards (reverse thrust) which could potentially move the plane backwards.And some variable pitch propeller aircraft (those that can change the angle of the propeller blades) can angle them to produce reverse thrust.

Most likely they don't because it's more efficient to have a tug, jet engines can be very inefficient at low speed plus of course they can't see behind them.

Answer 26

The jet engine only works for forward motion. It is impossible for it to propel itself backwards unless the jet engine were to be turned around. Air goes in the front and out the back faster.  

Answer 27

In one form or another, this question has been asked over 200 times already.

[ there are no engines driving the wheels, so the gears you mention can't be placed anywhere ....that I can think of !! ]

Sash.