Can Thrust Reversers be used to push back from the gate?

[shon7]

Kind of an odd question -- but can thrust reversers be used to push back from the gate?

I was under the impression that they just change the flow of air from the engines thereby creating the "reverse thrust." However, I was reading a book about Frank Lorenzo and his tactics and it mentioned something to the effect of not using agents to pushback and rather having pilots do it themselves with the reversers!

Finally, along the same lines -- would airlines save a lot of money if Boeing/Airbus started building airplanes with the capability to push back on their own?

 

[Dorkpilot]

Yes they can!!! It is called a powerback. You just don't see them as much these days because it uses a lot of fuel and you have the chance of FOD damage. Usually in places where they do powerbacks it is because of a broken tug or only a very few amounts of flights a day by an individual carrier.

 

[PSL]

I've seen the DC-9 series power back.

I used to do it in the B-727 (it was much easier with the -17 engines ... if memory serves the callout was something like ... 1.4 (EPR) feet on the floor. The last thing you want to do unless crunching the tail feathers was imminent was to touch the brakes with any rearward motion.

I know it's been done in the B-737(200) although not encouraged for a multitude of reasons. It's a major no-no to do it in the later series B-737s.

Most turbo-props don't permit it either for the same reasons as mentioned earlier. You can do it ... but the chances of FOD(ing) and engine, tearing up the prop blades with debris or tearing the nosewheel off with an agressive steering input make it foolish in my book.

 

[wmuflyguy]

I have seen Airtran do this in ATL

 

[STL717]

1.4(one point four) feet on the floor
2.0 (two point oh) look at us go!

 

[Rez O. Lewshun]

Need a real expert on this to chime in.....


Jets with wing mounted engines or cascade type reversers don't do powerback (B737) b/c of FOD. Rather FKs and DC-9 types do (did).

A technique was to go fwd slightly, hit the brakes and as the jets momemtum lurched back the pilot simultaneously went into REV. This allowed the jet to move back without alot of initial REV thrust.

The marshaller has big aircraft carrier deck goggles and does this rolling motion with his arms as the jet moves back. Looks like Travolta in Sat. Nite Fever. (which BTW Travolta looks better in a leasuire suit rather than a pilots uniform..but that is another thread)

It's pretty cool to watch. I've only seen American do it.

Anyone who has actually done/does it want to correct or add?

 

[njcapt]

It actually was a Boeing approved procedure in the 737-200. JT8 engines are fairly bulletproof, but the savings from not using a tug couldn't ever make up for the FOD potential. CFM56 737's absolutely can't do it.

I see NWA DC-9's and AirTran 717's do them all the time.

The BAe ATP I flew at UFS had a procedure for powerback, and we did it at ORD now and then. You REALLY couldn't touch the brakes in that thing, or you'd end up un the tail with a lot of 'splaining to do.

 

[PHX767]

Yep, that's about it.


Planes with bucket or clamshell types reversers can powerback. Newer high bypass engines don't have these, they use a translating cowl that slides back and diverts the fan air. Doesn't aim it backwards as the other type, mainly effective at high speed.

We did it at AA extensively with the 727 and MD-80, it does use a lot of fuel but it gets you away a minute or two earlier because you do not have to drop the tow bar and wait for the ground crew to clear. It's prpbably a wash as those same couple of minutes are spent cranking the engines at the gate.

Exactly right, planes with wing mounted engines would suck up all the trash on the ramp.
Right now fuel is precious, they would probably tow us to the runway if they could.

 

[ERfly]

I was reading somewhere that Eastern pioneered the powerback. Back when Borman was basically at war with the Machinists, he figured that you could save a ton of money by not having the mechanics (procedure at the time) push back the planes.

He authorized powerbacks for all fleet types, I believe, including the 757. I'm not sure how true that part is. I can imagine that it must be pretty complicated, noisy and dangerous to powerback an 757.

 

[320AV8R]

Our DC-9s powerback more often than they get pushed back. They opt for a pushback when in a conjested gate area, with snow or ice on the ramp, and when one reverser is inoperative.

 

[Gatorman]

Shhhhh

Don't tell anybody, but I have done it with a CL-601 a couple times. Strictly for maintenance purposes only!!!
...seeing how I am just a mechanic, hehehe.

You have to be very careful with a Challenger though, tapping on the brakes while rolling backwards result in tailcone damage, if you know what I mean.

 

[LearLove]

I was reading somewhere that Eastern pioneered the powerback. Back when Borman was basically at war with the Machinists, he figured that you could save a ton of money by not having the mechanics (procedure at the time) push back the planes.

He authorized powerbacks for all fleet types, I believe, including the 757. I'm not sure how true that part is. I can imagine that it must be pretty complicated, noisy and dangerous to powerback an 757.

Ding Ding Ding.... and we have a winner, power back may have been around before this but it wan't until this "event" that they became widley used.

 

[ivauir]

Right now fuel is precious, they would probably tow us to the runway if they could.

I am calling my bros at HQ right now! This is a great idea!

 

[91100 100 set]

The Air Florida 737-200 that hit the bridge in DCA attempted to powerback after the tug couldn't get traction on the slippery ramp. I don't remember if they actually did powerback or if the tug eventually worked, but I believe the NTSB considered that this powerback attempt was a contributing factor to the ice contamination of the EPR probes that more than likely led to the artificially low thrust setting on takeoff.

I have also seen AA do it at ROC with an MD-80, but all the times I remember the ramp was bare and dry.

 

[ERfly]

The Air Florida 737-200 that hit the bridge in DCA attempted to powerback after the tug couldn't get traction on the slippery ramp. I don't remember if they actually did powerback or if the tug eventually worked, but I believe the NTSB considered that this powerback attempt was a contributing factor to the ice contamination of the EPR probes that more than likely led to the artificially low thrust setting on takeoff.

The Captain of the Air Florida 737 (Flight 90) attempted to assist the tug by going into reverse on both engines. Even by doing that, they were unable to get the aircraft out of the gate. That procedure was not authorized by Air Florida. The only thing it did do was fill the engines and EPR probes with snow and other things.

I think that is one of the big reasons that airlines really only like MD-80/DC-9/717/727s to powerback...Less chance of FOD.

 

[DenverDude2002]

Everytime I'm in DFW I always see AA doing power backs without tugs, always sounds like they are taking off 10 ft from the concourses. I assume this is due to a lack of tugs at DFW?

 

[atldc9]

Up until about 1 year ago, powerbacks were the preferred method of leaving a gate for AirTran. We have Op's specs stipulating which gates at what airports we can powerout of, and whether or not turns were allowed.

We are not allowed to due it with a t/r inop, when winds are greater then 25 knots, or when snow, ice or slush contaminate the ramp. Obviously application of brakes while backing is prohibited.

The procedure is to start both engines, start it rolling to get the tires moving, come to a complete stop with the brakes, take the engines into reverse idle, release the brakes, drop the heels to the floor - a lot of guys put thier toes under the rudder pedal to avoid any impulse to step on the brakes, bring the power up just enough to continue moving. When it is time to stop, come out of reverse, move the power up, and you are gone.

We have pretty much stopped using the powerback at most stations due t our single engine taxi program. No point starting 2, shutting 1 down, restarting 1.

 

[efiscompmon]

Pinch-a-nickle has a procedure in the FCOM for powerbacks, requires two wingwalkers plus the marshal. Fairly common in the 72s and DC-9s as mentioned, providing the gate permits it! Fun to do in the sim, wouldn't care for the responsability in real life.

Of course, you can make a single engine t/o in the sim if you add power slowly enough....let's not give management any ideas there

 

[FLB717]

Efis,

Nice Avtar...NOT. You have some sick twisted sense of humor? Why not show a picture of the burnt out Firengine from 9-11 or the twisted bodies of small children after stepping on a landmine in Bosnia?

 

[-9Capt]

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