Even if it is fobidden, could a Boeing still make a push-back on its own by using the thrust reversers?

Question

Or is this technically impossible?

Answer 1

Technically, it's possible... But with wing-mounted engines, it's a major risk of damaging the engines by ingesting FOD.

Answer 2

Boeings can make power backs. The 727's that is. Fod is always a  danger and a good ramp crew will police the ramp for it before each flight. The real reason wing mounted aircraft are not authorized power backs is because they will experience tail tip down when they stop after powering back. Tail tip down is a major mess.

Answer 3

As stated, many aircraft are capable of doing this.  I've seen several MD-80s push back from the gate, under their own power.  There are several reasons why it's not really done much these days.  One being it's not exactly safe since you cannot see behind you.  A check airmen, at my first airline, did this in a small turbo-prop and hit the brakes to hard.  The tail of the plane hit the pavement.  Some airlines forbid the pilots from doing this.  There have been several occasions where the ramp crew asked me to do this (I never did it).

I did, however, see maintenance guys do this all the time at the end of the day when moving planes over to their hanger.

Answer 4

C-17 does it all the time.  Of course, the tail door opens and the loadmaster spots the pilot so they don't back into something.  They tried putting big 18-wheeler mirrors up by the cockpit, but they were always getting full of bugs.

Remember, TRs hardly impact landing distance on DRY runways, but they are life savers on wet or icy runways!

Answer 5

It's not forbidden and no its not impossible. Yes planes can reverse using reverse thrust

reverse thrust is  never used for backing up because of foreign object damage, and back flow of exhaust into the compressor, possibly damaging the engine.

certain aircraft are certified to use the engine's reverse thrust to back up like the DC-9

Answer 6

in reply to the genious that wonders if you'd get on a boeing thats been through many reverses, Uh, reverse thrust is used on almost every landing to slow the aircraft. Hint, thats why the engines rev up after landing and you almost kiss the seat infront of you.

Answer 7

From an engineering standpoint, the major reasons for not conducting pushbacks using thrust reversers is:

1. It adds unnecessary low cycle fatigue to the engine components. These cycles are rarely added into the log, and may be the reason for fatigue cracks showing up before they are expected in hot section teardowns.

2. That's not what the thrust reversers were designed to do.

I am not familiar with the flight manual on these aircraft. Does it include instructions for this particular operation?

Answer 8

I've been in lots of powerbacks in the 727.  It's very possible.

Answer 9

This question seems to keep reoccurring.

Several airlines in fact did powerbacks from the gates using reverse thrust on a regular basis for many years. Using DC-9, MD-80 and B-727 aircraft primarily, but there may have been other types that I'm not aware of.

There is nothing inherently dangerous or damaging about them, as long as the company procedures are followed. I have done hundreds of them.

As long as power was kept to approved levels and there were ground personnel that have a clear view of what is in back of the plane and can communicate with the crew, the powerbacks went very smoothly.

To the person who said the main reason for not using powerbacks is "tail tip down," I'm not sure where that info came from, the Captain never uses the brakes to stop, instead they use forward thrust. "Tail tip down," as you called it, was never much of an issue.          

The main reason for not using powerback these days is fuel conservation.

Answer 10

It's technically possible but it IS forbidden on several Boeing aircraft.

It is forbidden on the 747. It is forbidden on the 767, and I'm fairly certain several others too.

Quotes from the current version of my Boeing 767 Ops Manual:

"During taxi, use of reverse thrust above idle is not recommended due to the possibility of foreign object damage and engine surge".

"Backing with reverse thrust is prohibited" and in another section "Backing the aircraft with use of reverse thrust is not permitted".

There are big differences between using the thrust reversers when you have forward airspeed (like during landing), and when you do not, including a much higher risk of engine surging or stalling, and sustaining foreign object damage when stuff is blown up around the front of the engine then sucked in. This particularly applies to modern Boeings with pod-mounted engines under the wing, as almost all of their current models do.

So yeah, if my Boeing jet had been through any ground reverse cycles trying to back out of parking spots, I'd be concerned about the condition of the engines and especially how many times they'd been stalled, surged, or ingested FOD. That is not taking good care of a jet engine. On most Boeings, the engines are not designed to operate with thrust being deflected forwards while simultaneously moving backwards.