reverse thrust?

Question

why is it illegal for a 747 to use reverse trust to back up.

Answer 1

It's not illegal but technically a pilot need a tow vehicle for push backs, because they can't see out of the airplane during the push back and also it's not operational or safe to use reverse thrust at speeds below 80 Knots. (150 km/h) after landing, that means the pilot has to disengage the reverse thrust after the aircraft decelerates below 80 knots.

Answer 2

Susan is correct. The thrust reversers on a 747 are not designed for that.
However, the reversers on a C-17 ARE designed to back up the aircraft up a 2 degree incline.

Answer 3

I can't speak for 747's specifically, but I don't know it would be
"illegal". Any aircraft that does it has to be at a part of the ramp where that is allowed. It can be very dangerous for people and the aircraft. Especially for lower hung engines. Thrust is directed forward and can cause a lot of junk on the ground to get tossed in the air and injested by the engine. Then there is company policy. For example my airline does not allow mechanics to do it, unless it is a severe emergency or very high approval has been given. Pilots can only do it in an are designated for power backs, even then I don't think they can have passengers on board. CRJ's can go on their tail quite easily if you hit the brakes. I think it depends more who you are and where you are.

Answer 4

it is not illegal to use thrust reversers to back up a plane from the gate, however all engines have a designated speed at which thrust reversers CANNOT be used. such as 60 or 80 kts. this is why you see (if you have a window seat near the wing or back of the aircraft, [for an MD 80]). the thrust reversers close before the aircraft comes to a slow enough speed to exit the runway.

Answer 5

cause the pilot cant see behind the plane very well and if the engine isnt rated for it it might cause overheating in some part off the turbine and damage parts of it i for one know that it isnt illegal its just that its not safe most of the time and if the plane isnt designed for it can cause repair bills to go very high the dc-9 can do powerback for a short time and the c-17 globemaster 3 are two ive seen do it

Answer 6

Its not actually illegal, its just a bad idea. When TRs fire, they shoot air forward and onto the ground. this causes things like rocks, dirt, sticks, etc to be blown up into the air, where they are sucked into the engine by the main fans. these things cause expensive engine damage and wear down vital engine parts.

almost nobody uses TRs to back up. It *would* work, bust it can also wreck a multi-million dollar engine. Much cheaper just to push back.

Answer 7

BTW, when our C130s back up, they open the rear door so the loadmaster can see behind the aircraft. The rear view mirrors on a 747 don't give enough of a view... :-)

Answer 8

NOT that its illegal, its that the plane is too big to use reverse thrust, you would have to take the engine up to 100% on the ramp
and that would result in catastropic loss of ground crew as they get sucked into the engine.......

Answer 9

Ask your FAA commission.

Answer 10

sophisticated point. research on to yahoo and bing. that will may help!