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I watched some videos on YouTube where the pilot used the thrust-reverser for push-back instead of the push-back tug. Some examples:

MD80 Powerback

DC9 Ground Reverser Powerback

Is this procedure currently in use? Would an airline today certify a 737, or even turboprop, like a Beechcraft 1900D, to execute such a maneuver?

I've also seen a Boeing 727 video. 727s and MD80s have the engines attached directly to the fuselage, not in the wings. Would that be one of the reasons?

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  • $\begingroup$ American Airlines used to use it frequently circa early 2000's. I don't know if they still do it. I believe Crandall was trying to save money on ground crews. Crandall was as asshole; and I am glad he is gone. He ruined a lot of people's lives by turning careers into part time jobs. $\endgroup$ – jww Aug 2 at 7:13
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Most modern commercial airliners are prohibited to power back. Ground operations in aircraft fitted with high-bypass engines are usually restricted to idle and low-idle operations (enough to make the craft start moving, after which momentum enables further movement with idle only). Aircraft capable of power back are predominantly thus turboprops, several operators of these allow their crews to operate accordingly.

It's not in common use anymore, for the following reasons:

  • Thrust reversing can kick up a lot of debris, posing a safety hazard. This would generally preclude any ground crew or spotters walking under the jet as is often done during pushbacks.
  • The previous point's especially true for under-wing jet engine designs, so only jets with fuselage-mounted engines are allowed to do it, and most of the bigger designs (DC-9, MD-80, 727) are being phased out of most fleets.
  • Pilots in most craft can't see behind them, another possible safety hazard requiring multiple spotters to be in contact with the pilot.
  • Thrust reversing uses a lot of fuel, so it's usually cheaper for the airlines to use a guy on a tractor for an assisted pushback.
  • Thrust reversing is loud, and during a powerback that noise is in close proximity to the terminal. The tarmac's a noisy place, but usually not that loud.

If you want to see a powerback performed by a commercial airliner, fly out to L'Esperance in St. Martin. The runway there is very short and has no taxiway leading to the end of the runway from either end, so larger passenger turboprops that service that airport have to turn onto the runway about 2/3 down its length, face their desired takeoff direction, then powerback to the end of the runway in order to have enough to take off. The larger and (relatively) busier Princess Juliana International, on the Netherlands side, has taxiways and turnaround areas at both ends of its runway.

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  • $\begingroup$ That was what I wanted! For the aviation exchange team: POWERBACK != TAXI BACKWARDS $\endgroup$ – Ygor Montenegro Mar 20 '15 at 21:57
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    $\begingroup$ @YgorMontenegro please refrain from shouting. $\endgroup$ – Federico Mar 21 '15 at 10:50
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Any aircraft with thrust reversers or reversible props should in theory be able to execute a powered pushback, FOD and ground facilities damage notwithstanding. In a previous life I was an AC-130 crew chief -- loved the fact that those things could back up.

But I think the main reason you don't see many air carriers using their thrust reversers for pushback is because of the hazard to everything outside the aircraft -- people, baggage carts, fuel trucks, jetway bits, and the terminal windows. I can't find a reference for it at the moment, but I do remember one US airport banning powerbacks in the late 70's or early 80's after a gate area window was shattered. My recollection is that powerbacks fell out of favor and we started seeing tugs used everywhere around that time.

Here's a good ASRS article about not only powerbacks but blast damage incidents in general.

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    $\begingroup$ Actually, the biggest reason why it's not used much anymore by aircrarriers is fuel burn is excessive. $\endgroup$ – slookabill Mar 20 '15 at 10:01
  • $\begingroup$ I saw tons of powerbacks in the mid-to-late 90s. It seemed like MD-80/MD-90/DC-9 aircraft did it more often than not (at least here in the U.S.) back then. It wasn't until the 2000s that they seemed to start falling out of use. $\endgroup$ – reirab May 5 '15 at 15:30
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An air carrier must also have OPSPEC C065, POWERBACK OPERATIONS WITH AIRPLANES to do this.

OPSPEC C065—POWERBACK OPERATIONS WITH AIRPLANES.

A. General. C065 authorizes the use of powerplant reversing systems for rearward taxi operations. Before issuing C065, the principal operations inspector (POI) must determine whether the operator meets requirements discussed in AC 120-29, Criteria for Approval of Category I and Category II Weather Minima for Approach, current edition. Airplane types’ make, model, and series (M/M/S) authorized for powerback operations must be listed in C065. Airports where powerback operations are authorized must also be listed. If the POI and/or operator determine that restrictions to powerback operations are required at certain gates or ramp areas, the restrictions must be described (adjacent to the airport name) in the “Restrictions and Limitations” column. OpSpecs worksheets provide a template for listing authorized airplanes, airports, and restrictions.

B. Policies and Procedures for Ground Personnel During Ground Operations. Title 14 CFR part 121, §§ 121.133 and 121.135, part 134, § 134.23, and part 135, § 135.21, require certificate holders to prepare manuals setting forth procedures and policies that must be used by ground and maintenance personnel in conducting their ground operations. Sufficient procedures must be established to maintain an adequate level of passenger and company ground personnel safety during ramp operations. Procedures should emphasize safety during boarding and deplaning of passengers or cargo, specifically during times when an engine(s) may be running or a propeller(s) is turning during ground operations. Procedures should include, as a minimum, a means for defining no access areas around the propeller(s), as well as the landing gear and tugs, during push and ground marshaling operations. Policies should provide that an adequate number of ground personnel are assigned to ensure safety of company personnel and passengers.

C. Pushback and Ground Marshaling. Procedures for pushback and ground marshaling activities should be clearly defined and should include safety precautions and signals, and should ensure adequate visibility of assigned personnel during the time of aircraft movement.

D. Increased Awareness. FAA air carrier surveillance programs should emphasize increased awareness by inspectors and the strict need to follow safety procedures around turning propellers, in marshalling and pushback procedures, and/or other ground activities.

E. Other References. Additional references can be found in National Transportation Safety Board (NTSB) Recommendations 91-297, 91-298, and 93-146, and Air Carrier Operating Bulletin (ACOB) 8-94-2, Safety in Ground Operations.

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A plane can powerback if you can configure the engines to provide more backwards thrust than forward thrust.

Fixed pitch propellers can't provide any reverse thrust. With variable pitch props it depends on whether the there is enough pitch control to reverse it.

However powerback has the risk of debris getting into the engine. The air will blast forwards and possible damage the gate so it's not used there. That and the guys on the ground don't appreciate getting blasted.

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I've got a few hours in the 1900 and a couple hundred in the smaller KingAir. I think you can reverse the props while sitting still and push back with the negative thrust. But you probably shouldn't. You'd probably be safer doing it in the Beech than a 737, since the intakes on the Beech are significantly smaller (and have the prop directly in front of them pushing the air/debris outward). The 737 engine doesn't change the direction that it's sucking the air in. Just how it's blowing it out. I'd still think it would be a FOD nightmare.

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Both power back and taxiing under thrust are on their way out. Efficiency is horrible, so electrically powered wheels are planned for the next step in fuel efficiency improvement.

Not to be misunderstood: Currently this is not yet being used on production aircraft. But it looks likely to come.

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    $\begingroup$ This is probably a topic for a whole 'nuther question that would be closed due to the speculative nature of it, but are they really finding a way to electrically power the wheels with motors that are light enough to carry for the whole flight, thus making the efficiency of the whole system better than using some fuel for taxiing? $\endgroup$ – FreeMan Mar 20 '15 at 12:15
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    $\begingroup$ @FreeMan There is at least one company out there trying to design some sort of automated tug that would taxi it out to the runway, IIRC. To me, though, it seems like maybe taxiing out under power isn't such a bad idea, since it seems like you'd be more likely to detect any potential problems with the engines before takeoff that way. $\endgroup$ – reirab May 5 '15 at 15:33
  • $\begingroup$ FWIW, Delta Airlines also evaluated the possibility of using supertugs at ATL to for maintenance-related ground movements. I don't think the results of the simulation were actually published anywhere, but I've seen them in person and they indicated that, for the assumptions under investigation, this would have been an NPV-positive initiative. Can't rightly say whether this is something that would have also turned out positive for taxi-outs and -ins as supertugs are quite fuel-hungry and expensive in their own right, but the approach may be a viable third option, at least at major airports. $\endgroup$ – habu May 6 '15 at 13:30
  • $\begingroup$ @reirab just taxiing out is not always likely to reveal any serious engine problems due to the low power or thrust settings usually required for the task, which is why engine run-ups are so important. Though I will grant you that they would reveal the rather embarrassing problem of not being able to actually start the engine before reaching the runway :) $\endgroup$ – habu May 6 '15 at 13:34
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    $\begingroup$ Here's some info about eTaxi. lufthansa-technik.com/etaxi $\endgroup$ – Sports Racer May 27 '15 at 19:29

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