the dash8 turbo prop can back up. it does not reverse thrust the engines, just changes the blades to a negative angle. was (is?) common at small airfields with no tugs.

do jet engines acutally reverse and reverse thrust, or just stick a blocker thing over the output, and blow fwd?

had to look it up... video of c-17 pushback

http://www.youtube.com/watch?v=XkzXzDdkdf8

The latter. The engines can only suck in air, so reverse thrust blocks the exhaust and directs it forwards (more or less) around the engine. You can see this with the clamshell-type reverse thrust on a 737-200 or MD-80.

Remember this only once at DTW in mid 80s...so must have been a NW flt.

One would think that costs a lot of fuel.

Apparently, FL did this with their 717 at TPA. The video clip shows their ground marshall running/chasing towards the nose of the plane because the plane is reversing on its own power and turning at the same time. See:

http://www.youtube.com/watch?v=KdWEA...eature=related

When I used to be a line guy, some pilots would do exactly as I marshaled and some would do whatever they wanted irrespective of what I motioned them to do. For something like this though (granted, the ramp area at this airport seems fairly slow) there is a lot of responsibility on the line guy's part.

Also, I can and cannot believe they still do this! This video is obviously recent, maybe -5 years tops. Part of me thinks, well, if there's no tug what other practical way of pushing a plane back is there? The other part thinks that this takes a lot of fuel to do and would be greatly frowned upon by any airline in our current fuel conscious days.

Powerbacks (what these are termed) have pretty much come and gone. Firstly, due to the inefficiency when the thrust reversers are deployed compared to normal forward power, you need a lot of thrust to get backwards movement, which can be hazardous when in close proximity to ground equipment and crews, etc, so a significant number of airport operators just banned it outright. Secondly, the dirt kicked up by reverse thrust was just about acceptable for tail mounted engines, but not for underwing, closer to the ground, so as 727s and DC9s have been replaced by ubiquitous 737s and A320s, the approach has gone.

Prop aircraft can do it much more effectively by just going into reverse pitch on the propellers; the Dornier 328 operator from London City to Edinburgh always uses it at the latter point to back away from the terminal under marshallers control. The subsequent transition from reverse to forward movement is instantaneous.

Northwest used to power back from the gate quite often with their large fleet of DC-9's. I've been on 10+ flights when they did this, however it's been sometime since it's happend.

My bad that there was a previous thread on powerbacks.

I was doubting my memory (that it occurred on a B732) until I read that Air Florida 90 occurred on a 732. http://en.wikipedia.org/wiki/Air_Florida_Flight_90

AA did this for a year or two at DFW. Mostly with their MD80s but also with other planes.
Was kind of noisy, but fun to watch to see the reverse thrust of the planes leaving the neighboring gates.

Several times years ago on AA's B727's at both DFW and ORD. At ORD, we watched as an MD-80 beside us backed out under power then we did the same. Very noisy as the thrust reversers were used, but it saved time waiting for the tugs. As mentioned above, I always thought that aircraft with wing mounted low engines weren't allowed to do the reverse thrust backout due to sucking in debris because of the lower mounted engines, but I didn't realize that was given as one of the reasons for the tragic Air Florida crash in D.C. Thought it was a long delay after deicing at the time.

bj-21.

It was that too -- IIRC, it was a combination of a number of things, any one of which was inexcusable: Powering back at the gate (pulling snow and ice into the engine sensors), tailing a DC-9 while taxiing to remove wing ice with its engines instead of delaying to deice again (which just caused it to refreeze farther back in an even worse place), non-sterile cockpit conversations (including the pilots going through the checklist and even saying that the anti-ice systems were off, when they should have been on), and not reacting by either aborting the takeoff or firewalling the engines (the iced sensors made the gauges read as if full power when they were far from it). Really reflected badly on the pilots and the airline; I remember watching news of the sad tragedy, including true acts of heroism from those who jumped in the icy waters to save the few survivors...

Oh yes, but then again I've done dozens of DC-9 and MD-80 flights over the years. I think the most recent ones I can remember were on AA MD-80s in the mid-2000s.

There was an incident with an American Airlines B-727 at YYZ back in the eighties.

During power-back the main gear contacted a low wall, coming within inches of a catastrophic 40' fall.

Where it happened.

http://chuckmanothercollectionvolume...rport-new.html

I think the C-5s did it way way back. Supposed to have been designed for use in unsupported airfields w/o support equipment but it as rarely used for such. I saw an old video of one doing such. Not sure if the C-141s could do the same.