airplanes / reverse gears?

Question

Why are there no reverse gears on planes?

Answer 1

There is, its called thrust reversers when used for a "power-back" which is the equivalent to a push back, with the exception that a push back does not use engines... This is only seen on a select few airplanes... and only airplanes with tail mounted engines... it is rarely used now because it takes alot of fuel... The reason you dont see it more often is that the pilot cannot see backward in the airplane... wouldnt want to bump into something in a milti-million dollar airplane..

Answer 2

The only gears in an aircraft is to convert some of the engines torque to hydraulic and electrical power. They do not move the aircraft at all, if they did when the thing took off it would lose all speed.

There are a variety of reverse thrust options available either by changing the pitch of the propellers to direct air forwards instead of backwards, or else the more simpler method used on jet aircraft by throwing a 'bucket' behind the engine to re-direct the jet exhaust forwards.

Aircraft can be moved backwards using reverse thrust but in the case of jet aircraft this is potentially very damaging to the engines if any debris is blown in to the engine air intake.

There is also no need for an aircraft to move backwards except when leaving the stand and there are tractors there to do that (the pilot can't see whats behind him either) - so why would he need reverse gears. If an aircraft doesn't need something it wont be fitted in order to keep the weight to a minimum.

Answer 3

There's been enough on here about how thrust is reversed (for braking, mainly) but the reasons it's not often used to "reverse" an aircraft on the ground are:
a] The pilots cannot see where they are going
b] It kicks up a hell of a lot of noise, dust and debris around a terminal building
c] It can blow over equipment and personnel around the gate.
d] The time occupied during a pushback by a tug is often used for starting engines, so they are stabilised & running properly by the time the push ends. Jet fuel costs money, it's cheaper to use a tug than to run the engines unnecessarily.

Sometimes you may see a C130 or a C17 back up on the runway, but you'll notice it's only out on the runway they do this and, if you look closely, you'll notice the ramp is lowered and the loadie is looking out.

Answer 4

is this a trick question because i cant find a plane that has more than one gear, prop or jet . but i know of two planes that can fly backwards.A MiG by the skill of the pilot and a harrier jump jet .If it is a trick question then the answer must be Concorde as by its speed it could reverse the gears in the clock and land in the USA before it left the UK . Or may be i just read the question wrong . any way good luck with your search for an answer

Answer 5

Most of the larger planes do have reverse thrust. C-130 and C-17 can use reverse thrust to back up the runway, Pilot follows directions from the guy on the ground. Passenger flights normally only use reverse thrust to shorten the landing roll.

Answer 6

Airplanes don't have forward gears either. They just roll along on their wheels using the thrust from the engines.

Reverse Thrust (already explained by everyone else here) is used solely for deceleration after landing. Using reverse thrust for reversing the airplane on the ground is very unusual and never used on large airliners because the power required to move the plane backwards would cause a surge in the engine compressor requiring it to be shut down immediately.

Answer 7

Technically there isn't a forward gear. Most aircraft use thrust to move forward or go in reverse while on the ground or are assisted by ground crew and given a "Push" so to speak. Some have vents to channel the plane's trust in the opposite direction others the props turn to reverse air flow with out the engine turning in the opposite direction.

Answer 8

Most jet will likely have the thrust-reversal system, and might be capable to back the plane up without the need of a push back tractor. Capable doesn't mean allowed, though. Things like foreign object ingestion and traffic collision are some of the things that prohibit the use of "power backs". And if you're allowed to "power back" like the DC-9s, you just can't simply hit the brake if you feel you've backed-up enough and want to stop. The plane will tip-up. You'll need to counter-thrust the movement to stop. It means that you can't just stop whenever you want (or need) it, it'll need some time for the engines to close the reverser, and then spool-up for the forward thrust to begin stopping the aircraft. The pilots also don't really know how much and how far they have to turn, because they obviously don't have a rear view-mirror! I'd say, it's not the safest thing to do.

Answer 9

Some airplanes sort of do. Jetliners like Boeing, Airbus, McDonnell Douglas, have flaps that open out of the engine to push the thrust forward, kind of like pushing backwards to slow planes down.

Some propellor planes have a reverse pitch which will direct some thrust backwards (very little) that helps to slow down the plane.

Planes are not like cars. The plane is not pushed/pulled by the wheels. They are simply there to overcome friction. All the work is done by air pushing backwards from the engines...

Answer 10

There is a reverse gear for the engine to reduce its speed when landing. But no reverse gear like the way cars do. There's no point in going backwards in the air. Lol.