DLCnxgptjax
Topic Author
Posts: 240
Joined: Tue Oct 11, 2005 10:27 am

Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 2:53 am

I was on NW flight 388 MEM-GPT on 11/23. We use the DC-9's own power to pushback from the gate. I know that other airlines have/still use reverse thrust to pushback from the gate without a tug, but I was thinking that maybe it would be more cost effective to use a tug for pushback. I was thinking maybe the Captain decided that he would rather go ahead and push rather than wait for an available tug. Just wondering what others thought as far as the current state of fuel and how significant, if at all, this event was.

On a side note, I experienced my first go around on an airliner on that same day. It was on a Delta 763 JAX-ATL. I had the largest grin on my face...  Big grin
 
dogfighter2111
Posts: 1867
Joined: Tue Nov 09, 2004 3:02 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 2:57 am

Hey,

Don't they only do that because the DC-9's have those Cone things that go over the rear of the engine. I know that is the reverse thrust, but i don't think it is possible to do that in a B757 or B747 etc. If so wouldn't it blow out the windows in the terminal?

Thanks
Mike
 
jcavinato
Posts: 392
Joined: Sun Jan 02, 2005 9:14 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:00 am

Eastern Airlines started the practice (to my memory), because the airport tug fees were in the $30 - 40 range for each push back. It was a balance of fuel vs airport fee tradeoff. But, with fuel costs still being high (when Eastern did it, fuel was about $0.18/gallon), I can't see IT being the low cost alternative. There had to be another reason(s).
 
FoxBravo
Posts: 2769
Joined: Fri Nov 21, 2003 1:34 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:02 am

Quoting Dogfighter2111 (Reply 1):
Don't they only do that because the DC-9's have those Cone things that go over the rear of the engine. I know that is the reverse thrust, but i don't think it is possible to do that in a B757 or B747 etc. If so wouldn't it blow out the windows in the terminal?

Theoretically I believe just about any aircraft with reverse thrust could power back, but it is not typically done by aircraft with wing-mounted engines because of the risk of FOD damage, nor is it done by aircraft above a certain size because of the resulting jet blast. I have only seen it done by DC-9s, MD-80s and 727s.
Common sense is not so common. -Voltaire
 
md90fan
Posts: 2798
Joined: Fri Jul 29, 2005 11:15 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:10 am

I saw a DC-9 did pushback at BTR  Smile
http://www.devanwells.blogspot.com/
 
bohica
Posts: 2298
Joined: Tue Feb 10, 2004 3:21 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:14 am

Quoting DLCnxgptjax (Thread starter):
I was thinking maybe the Captain decided that he would rather go ahead and push rather than wait for an available tug.

All powerback procedures have to be approved in the airline's operating specifications as well by the airport authority of the airport where the powerback is taking place. Also you will need at least two wingwalkers and a marshaller for a powerback.

Quoting DLCnxgptjax (Thread starter):
Just wondering what others thought as far as the current state of fuel and how significant, if at all, this event was.

Considering the cost of fuel, is is more cost effective to use a tug.

Quoting Dogfighter2111 (Reply 1):
Don't they only do that because the DC-9's have those Cone things that go over the rear of the engine. I know that is the reverse thrust, but i don't think it is possible to do that in a B757 or B747 etc.

I flew on several EA 757 flights out of ATL and they powered back out of the gate. I don't think any airline ever did powerbacks on a widebody. That would be asking for trouble, FOD, etc.
 
User avatar
United_fan
Posts: 6358
Joined: Fri Nov 24, 2000 11:11 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:19 am

NW does it in DTW,too . But not GSO or ROC . At least that's been my experience.
Champagne For My Real Friends,and Real Pain For My Sham Friends
 
KC135R
Posts: 696
Joined: Sun May 01, 2005 6:38 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:20 am

Quoting FoxBravo (Reply 3):
Theoretically I believe just about any aircraft with reverse thrust could power back, but it is not typically done by aircraft with wing-mounted engines because of the risk of FOD damage

I believe this is true. Several years ago, at the Berlin air show, I got the chance to talk to some Boeing folks. The C-17 had just performed a little demonstration and a big deal was made about its ability to back up. So I asked them why it was so special, couldn't any aircraft with TRs back up? They said yes, in theory, but FOD would be a concern and also some engines would have a tendency to overheat during a power back.


On a side note, last year when I was traveling home for thanksgiving, I flew NW. Leaving out of MSP (DC-9) the Capt came on and said "Folks, we should be pushing back - no, scratch that, powering back here in just a few minutes." I knew I was an aviation geek when that comment brought a smile to my face - everyone else probably didn't even know what he was talking about.
 
AsstChiefMark
Posts: 10465
Joined: Thu Feb 05, 2004 2:14 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:27 am

Powerbacks are common at MSP. You can hear one every few minutes. It seems like half of the NW DC9 flights from MSP that I've been on were powerbacks.

Mark
Red tail...Red tail...Red tail...Red tail...Red tail...Red tail...Red tail...Red tail...Damned MSP...Red tail...Red tail
 
ETStar
Posts: 1850
Joined: Mon Jan 12, 2004 6:25 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:28 am

Quoting Bohica (Reply 5):
Considering the cost of fuel, is is more cost effective to use a tug.

I think nowadays, considering the high labour costs and every airline's intentions of slashing them, the reversers are a good alternative. I am sure the airlines are calculating this amount on a regular basis to determine what is best for them.
 
AirCop
Posts: 5553
Joined: Mon Nov 28, 2005 2:39 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:36 am

Powerbacks are common at DFW with American at certain gates with the MD-80.
 
wjcandee
Posts: 5126
Joined: Mon Jun 05, 2000 12:50 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 4:36 am

Quoting KC135R (Reply 7):
The C-17 had just performed a little demonstration and a big deal was made about its ability to back up.

I think not only back up, but back up a 2 percent grade. Pretty impressive.
 
fpofllflyboi
Posts: 224
Joined: Fri Jun 03, 2005 10:30 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 4:43 am

Quoting AirCop (Reply 10):
Powerbacks are common at DFW with American at certain gates with the MD-80.

True, I flew DFW-FLL last year October and say at least 7 AA MD80's perform powerbacks.
 
KC135R
Posts: 696
Joined: Sun May 01, 2005 6:38 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 4:51 am

Quoting Wjcandee (Reply 11):
I think not only back up, but back up a 2 percent grade. Pretty impressive.

Indeed, and fully loaded it can do this - from www.boeing.com:

The four engines are Pratt & Whitney PW2040 series turbofans, designated as F117-PW-100 by the Air Force, each producing 40,440 pounds of thrust. The engines are equipped with directed-flow thrust reversers capable of deployment in flight. On the ground, a fully loaded aircraft, using engine reversers, can back up a two-percent slope.
 
Web
Posts: 317
Joined: Thu Jun 23, 2005 6:56 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 6:31 am

Being in an aircraft during a powerback is awesome! I was on a NW DC-9-30 in DTW and we powered back. I was sitting about 2 rows ahead of the engine, and wow, is that loud! Definately something everyone here should experience before the aircraft capable of it are retired  Sad.
 
isitsafenow
Posts: 3413
Joined: Sun Feb 01, 2004 9:22 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 6:44 am

Powerbacks are permitted at few DTW gates. Just don't hit the brakes after you complete the maneuver.
safe
If two people agree on EVERYTHING, then one isn't necessary.
 
Cadet57
Posts: 7174
Joined: Mon Jul 25, 2005 2:02 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 7:38 am

FOD?

filler

thanks
Doors open, right hand side, next stop is Springfield.
 
User avatar
United_fan
Posts: 6358
Joined: Fri Nov 24, 2000 11:11 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 8:42 am

Foreign
Object
Debris
Champagne For My Real Friends,and Real Pain For My Sham Friends
 
DLCnxgptjax
Topic Author
Posts: 240
Joined: Tue Oct 11, 2005 10:27 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 8:49 am

Quoting KC135R (Reply 7):
I knew I was an aviation geek when that comment brought a smile to my face - everyone else probably didn't even know what he was talking about.

The exact same thing happened to me when I heard the engines start up before we ever moved. I was trying to hide the fact that I was so excited because I didn't want people to look at me and think I was up to no good.

 bouncy 
 
AzoresLover
Posts: 756
Joined: Sun Jun 27, 2004 4:43 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 10:26 am

Quoting United_Fan (Reply 17):
Foreign
Object
Debris

Are you sure? I thought in the Air Force we called it:

Foreign
Object
DAMAGE
Those who want to do something will find a way; those who don't will find an excuse.
 
User avatar
United_fan
Posts: 6358
Joined: Fri Nov 24, 2000 11:11 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 10:35 am

Champagne For My Real Friends,and Real Pain For My Sham Friends
 
IAHERJ
Posts: 527
Joined: Sun Jun 03, 2001 1:52 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 11:18 am

I've performed them on the B717 when I used to work ar AirTran. They worked out well and I believe that MSY still employs the use of powerbacking as the normal way of departing the gate to this day. The last one I did was a month ago in PNS. I've been a pax on a 737-200 (Continental) several DC-9's (Continental, Northwest) and MD-80's (Republic??Continental,American) and several Continental 727's that powerbacked.

From a pilot's perspective, they are quick however you have to start both engines on a two engine aircraft to perform the maneuver and a long taxi requires much more fuel or the shutting down of an engine after the powerback and a resulting restart before departure. I personally like doing them. I once initially applied a bit too mouch reverse thrust and blew a gate agents skirt up(it might of been a flight attendant standing in the jetway next to the agent).

Good thread

IAHERJ
Actually flown: EMB-120 EMB-145 B717 B737 B757 B767
 
srbmod
Posts: 15446
Joined: Tue Mar 20, 2001 1:32 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 11:34 am

Quoting Jcavinato (Reply 2):
Eastern Airlines started the practice (to my memory), because the airport tug fees were in the $30 - 40 range for each push back. It was a balance of fuel vs airport fee tradeoff

Nope. Eastern started doing powerbacks as a way to get rid of maintenance workers whose only job was pushing back a/c. Needless to say, the mechanic's union (the IAM) was none to happy about this. One of the union higher ups actually went as far try to block an a/c from being powerbacked. Needless to say, he wasn't successful, as it became S.O.P. at a number of airlines (depending on the airport). The reason why some airlines (like AirTran) have pretty much abandoned the practice was not entirely due to the rising fuel costs, but also to save money on maintenance costs as well.
 
User avatar
NWOrientDC10
Posts: 1283
Joined: Sun Mar 06, 2005 12:18 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 12:30 pm

After the downing of KAL flight 007, the ground crew at JFK refused to provide push back svc. for Aeroflot in protest. After it was determined that windows wouldn't be shattered, the powerbacks were allowed (I read this in an article after KAL 007 was shot down).

Personally, I felt bad for the Aeroflot crew; they didn't shoot down KAL 007  Sad.
I'm not sure when pushback svc. was resumed.

Good day  Smile

Russell
Things aren't always as they seem
 
Electech6299
Posts: 606
Joined: Fri Aug 19, 2005 11:13 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 12:31 pm

Quoting Jcavinato (Reply 2):
Eastern Airlines started the practice (to my memory), because the airport tug fees were in the $30 - 40 range for each push back. It was a balance of fuel vs airport fee tradeoff.



Quoting Srbmod (Reply 22):
Eastern started doing powerbacks as a way to get rid of maintenance workers whose only job was pushing back a/c



Quoting Bohica (Reply 5):
you will need at least two wingwalkers and a marshaller for a powerback.

 scratchchin   confused  So how many ground crew are required for a pushback? I count at least 3 for a powerback- aren't pushbacks routinely done nowadays with only one tug operator and one marshaller, hence all the cries for the return of wingwalkers? I guess it depends on the airline, but can anyone explain this to me?

Quoting IAHERJ (Reply 21):
I once initially applied a bit too mouch reverse thrust and blew a gate agents skirt up

You naughty Captain... wideeyed   eek 
Send not to know for whom the bell tolls...it tolls for thee
 
Midwest717
Posts: 74
Joined: Wed Feb 16, 2005 7:06 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 12:37 pm

For my trip to YYZ this week, the NW DC-9 used its reverse thrust to push back from the the gates in both DTW and YYZ.
 
FlyMeToTheMoon
Posts: 189
Joined: Sat Jul 24, 2004 9:01 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 1:42 pm

C-17 use thrust reverses quite frequently, if fact they are designed to go about 3 miles per hour on a runway with a max 5 degree slope.
Fly me to the moon... but not through LHR!
 
jbmflyer
Posts: 34
Joined: Mon Nov 07, 2005 9:50 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:11 pm

I thought the DC-8 was able to deploy the inboard two thrust reversers in flight as well as a way of slowing in a decent (not sure, someone correct me if I'm wrong)

Again, I THOUGHT a C-17 crashed during testing after all four reversers deployed in flight while on an approach or something to that end

was it ever discerned if the powerback was a contributor to the Palm Flight 90 crash in D.C.?
A pilots heart, mind and soul stuck in a 8-5 bankers chair.............
 
legendDC9
Posts: 458
Joined: Sun Nov 21, 2004 9:24 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:24 pm

Well, while watching the cost of fuel is nice and sweet, you have to remember that an enclosed pushback tug (and we are talking capable of a DC9, nothing special) is roughtly 100k to purchase. Not that NW doesn't have any, ofcoarse they do, but if you are looking at buying multiple units to fill the ramp in MSP/DTW or vice-versa buy one to use once a day in some out station, it becomes a much closer call on the fuel usage. Plus, don't forget that fuel is paid over time while purchasing GSE is an upfront cost. I think I read somewhere that NW is not doing well financialy these days...
 
wjcandee
Posts: 5126
Joined: Mon Jun 05, 2000 12:50 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 3:54 pm

Quoting Jbmflyer (Reply 27):
I thought the DC-8 was able to deploy the inboard two thrust reversers in flight as well as a way of slowing

There's a recent thread on this. The answer is yes, they can be used kind of like speedbrakes on the DC-8, and some other planes (notably Russian) can do it as well.

Quoting Jbmflyer (Reply 27):
was it ever discerned if the powerback was a contributor to the Palm Flight 90 crash in D.C.?

From ntsb.gov: "The National Transportation Safety Board determines that the probable cause of this accident was the flight crew’s failure to use engine anti-ice during ground operation and takeoff, their decision to take off with snow/ice on the airfoil surfaces of the aircraft, and the captain’s failure to reject the takeoff during the early stage when his attention was called to anomalous engine instrument readings. Contributing to the accident were the prolonged ground delay between deicing and the receipt of ATC takeoff clearance during which the airplane was exposed to continual precipitation, the known inherent pitchup characteristics of the B-737 aircraft when the leading edge is contaminated with even small amounts of snow or ice, and the limited experience of the flightcrew in jet transport winter operations." Could it have had some hypothetical effect? (You mean, like, blew snow all over the aircraft?) Maybe. However, having pitot tubes frozen over because the dumbass didn't turn on the anti-ice, leading to anomolous readings, and then having truly crappy CRM wherein the captain poo-poohs the FOs repeated objections that the thing isn't right and the FO as PIC doesn't have the balls to state a clear objection to takeoff, leading to basically an "oh, sh.." by the captain when he finally takes the controls after rotation on a leg that the probably should have been flying in the first place. Any one of those factors different, and the public never would have heard the callsign "Palm". While one could argue that I'm being too hard on the dead guys and the defunct airline (for insufficient training in, among other things, winter ops and cockpit management procedures), my personal belief is that the dead guys, were they not dead, would be the first to admit that they effed up.
 
sanscott744
Posts: 88
Joined: Sun Nov 30, 2003 3:43 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 4:23 pm

About 12 years ago when I lived in ATW. Northwest used to push back their DC-9's from GRB using the reverse thrust method versus the tow.
 
tribird1011
Posts: 196
Joined: Mon Mar 14, 2005 10:08 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 5:07 pm

Quoting Midwest717 (Reply 25):
For my trip to YYZ this week, the NW DC-9 used its reverse thrust to push back from the the gates in both DTW and YYZ.

Although the DC-9 might have powered back at DTW, I have serious doubts that it powered back at YYZ. Couple of reasons: firstly I don't think that the GTAA allows powerbacks, and second the gates normally used by NW at YYZ (usually B14, B15 or B16) require 90* turns either left or right immediately after clearing the gate area.
 
apodino
Posts: 3025
Joined: Mon Apr 04, 2005 2:11 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 7:13 pm

Does powerback really cost more? Yes the fuel costs high, but diesel fuel is more expensive than the jet fuel these airlines pay for. I would think that what they save in jet fuel, they more than use with a tug in diesel fuel.


Why can't most places do what they do here in ATW? Most airlines don't even push, they just do a 180 on the ramp out of the terminal. And yes, we do have jetways here in ATW.
 
sunking737
Posts: 1114
Joined: Tue Feb 22, 2005 10:33 pm

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 9:28 pm

When I worked for the Old Republic Airlines, my favorite part of the ramp job was the power back. We not only PB the DC-9's but 727's & CV-580. I think the whole idea was it saved time as the plane did not have to wait for tug to unhook, just slowed, stopped, and turned out.

Winter in MSP was rough for the guy doing the power back, you would get a face full of snow and de-ice. I remember wearing goggles to protect the eyes.

One of the guys wanted to PB a new 757, the Captain said no way. It would have been cool to see.
Just an MSPAVGEEK
 
797charter
Posts: 154
Joined: Wed Jun 15, 2005 4:32 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 10:06 pm

To all of you, - two very nice power-pushbacks videos -

C-17: (From outside)
http://www.flightlevel350.com/viewer.php?id=3327

Northwest DC 9-41 (From inside)
http://www.flightlevel350.com/viewer.php?id=668


What can I say more than: Enjoy!
Keep it clear of the propellers
 
aeroperu
Posts: 39
Joined: Wed May 25, 2005 4:18 am

RE: Northwest Using Reverse Thrust For Pushback

Mon Nov 28, 2005 10:28 pm

I too have had numerous pushbacks on NW DC-9's at DTW. And as has been stated here before, I have to hide the smile as folks would think there is something wrong with me....the writing down of regs doesn't help....  Smile

Doesn't this thread bring out a statement that we are all thinking....aren't we all glad that NW still flies the DC-9!!! Which begs the question, How long will they be flying them anyway??  duck 
Alas peruanas en los cielos del mundo....
 
captainstorck
Posts: 51
Joined: Sat Sep 03, 2005 1:40 am

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 12:08 am

I had my first DTW connection experience yesterday and when I departed CMH on a DC-9, we used a tug, but when we pushed from DTW in a 9, we used the reverse thrust. I also noticed at least 5 other NWA DC-9's do the same.
 
DC8FriendShip
Posts: 235
Joined: Fri Apr 29, 2005 7:35 pm

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 12:37 am

Quoting Wjcandee (Reply 29):
However, having pitot tubes frozen over because the dumbass didn't turn on the anti-ice, leading to anomolous readings,



Quoting Wjcandee (Reply 29):
the flight crew’s failure to use engine anti-ice during ground operation and takeoff, their decision to take off with snow/ice on the airfoil surfaces of the aircraft, and the captain’s failure to reject the takeoff during the early stage when his attention was called to anomalous engine instrument readings.

The Pitot tubes are separate from engine instruments, as are the anti- ice for both. the engines may have had anomolous readings, but the airspeed may have been true.
Come fly the Friendly Skies of United
 
thegooddoctor
Posts: 418
Joined: Thu Nov 10, 2005 8:12 am

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 12:37 am

Quoting Jcavinato (Reply 2):
Eastern Airlines started the practice (to my memory), because the airport tug fees were in the $30 - 40 range for each push back. It was a balance of fuel vs airport fee tradeoff. But, with fuel costs still being high (when Eastern did it, fuel was about $0.18/gallon), I can't see IT being the low cost alternative. There had to be another reason(s).

Another consideration, especially at places like DTW, is how much at TUG costs. When I worked, I believe they told us a pushback was something in the neighborhood of 100,000 USD for a large jet tug (this was told when they lectured us on the cost of the equipment during training). Maybe some of the MX guys can back this up or correct the figure I've given. But if this is the case, it's more economical to powerback as many DC-9s as you can at places like DTW and use the tugs for all of the A320 and up size jets rather than buy enough tugs to operate 100 gates.

S
The GoodDoctor
 
FoxBravo
Posts: 2769
Joined: Fri Nov 21, 2003 1:34 pm

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 1:07 am

Quoting LegendDC9 (Reply 28):
Well, while watching the cost of fuel is nice and sweet, you have to remember that an enclosed pushback tug (and we are talking capable of a DC9, nothing special) is roughtly 100k to purchase.



Quoting Thegooddoctor (Reply 38):
Another consideration, especially at places like DTW, is how much at TUG costs.

Definitely. In my experience, I have generally seen powerbacks only at hubs (e.g., DFW, MSP and RDU back when AA had a hub there) where aircraft depart in banks around the same time. It just wouldn't make sense to purchase a tug for every gate, especially when many of the aircraft (DC-9s in NW's case, MD-80s at AA) are capable of powering back. At smaller stations, however, this is less of a concern, so if a tug is available it might make more sense to save the fuel and push back instead.
Common sense is not so common. -Voltaire
 
jbmflyer
Posts: 34
Joined: Mon Nov 07, 2005 9:50 am

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 1:55 am

Quoting Dc8friendship (Reply 37):

I believe the airspeed was off as well, which was why they were so surprised when the shaker/pusher went off. I know in the end all they had to do was push the throttles forward and they would have been fine, as would have been evident by the fuel flow they saw. I know that after learning about what howard Stern said about the accident on his radio show I swore I'd never listen to him, and never have.
A pilots heart, mind and soul stuck in a 8-5 bankers chair.............
 
LXLucien
Posts: 314
Joined: Sun Mar 20, 2005 2:51 am

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 2:15 am

Hi

Quoting Jcavinato (Reply 2):
Eastern Airlines started the practice (to my memory), because the airport tug fees were in the $30 - 40 range for each push back.

Yeah but a new engine will cost Millions Big grin

Once in Male (Maledives) an Belair A310 was making pushback as suddently the pushback truck broke down and it was the only one in Male for the A310  Sad
So the Crew made for the last 10meters an "power-pushback". As soon as the startet the reverser, one of the engines overheated and also broke down  Smile So they had to wait two days for a additional engine... I think this was the first AND last power-pushback of this captain Big grin

LXLucien
Quote "Syriana": "Beirut, it's like Paris in the Mid-East"
 
dfwagt
Posts: 72
Joined: Fri Aug 26, 2005 2:39 pm

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 2:26 am

Quoting AirCop (Reply 10):
Powerbacks are common at DFW with American at certain gates with the MD-80

We stopped doing power backs to save on gas and wear and tear on the engines. It is a much quieter place to work now.
 
greasespot
Posts: 2955
Joined: Sat Apr 24, 2004 10:48 am

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 2:49 am

Quoting LxLucien (Reply 41):
Once in Male (Maledives) an Belair A310 was making pushback as suddently the pushback truck broke down and it was the only one in Male for the A310
So the Crew made for the last 10meters an "power-pushback". As soon as the startet the reverser, one of the engines overheated and also broke down

Not possible. A high bypass turbofan's reverse thrust directs only the bypass air. The core where EGT is read is NOT changed in direction.

Reverse thrust puts no more stress on an engine than landing. In fact on landing it is more stress as it is in reverse for longer time.
If the engine overheated it was not because of reverse thrust.

GS

P.S check my profile if you do not think i know what i am talking about. I have been involved in every aspect of engine mtce from line to overhaul...
Sometimes all you can do is look them in the eye and ask " how much did your mom drink when she was pregnant with you?"
 
GQfluffy
Posts: 3072
Joined: Tue Apr 19, 2005 1:25 pm

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 3:40 am

So how do you explain the C-17?

Aren't those 4 PW's the very same engine on the 757?
This isn't where I parked my car...
 
LXLucien
Posts: 314
Joined: Sun Mar 20, 2005 2:51 am

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 3:54 am

Hi

It's to complicate and it would take too long to write all down.
But that's what I've heard.



If you make a pushback with reverser, the hot air from the engine will go throat the engine again instead of colder air (20�C) like it is at landing...
please correct me if i'm wrong  Smile
LxLucien

[Edited 2005-11-28 19:56:46]
Quote "Syriana": "Beirut, it's like Paris in the Mid-East"
 
thegooddoctor
Posts: 418
Joined: Thu Nov 10, 2005 8:12 am

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 4:10 am

Quoting LxLucien (Reply 45):
you make a pushback with reverser, the hot air from the engine will go throat the engine again instead of colder air (20�C) like it is at landing...
please correct me if i'm wrong Smile
LxLucien

Something important to point out with your picture - a Fokker 70 vectors ALL thrust forward (core as well) due to the clamshell design. An A310 series aircraft does not use clamshells - Greasespot knows what he's talking about, bypass thrust only. Furthermore, the thrust of an A310, like that of other larger engine/nonclamshell engines, is directed at a more perpendicular angle (designed to create drag more than anything else) which would mitigate some of your proposed high-temp thrust ingestion.
The GoodDoctor
 
crownvic
Posts: 1730
Joined: Wed Oct 20, 2004 10:16 pm

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 2:27 pm

Greasespot...While your comment about the bypass air is correct, the RB211-535E4 on EAL's 757-200's also operate in this manner. Being that I sat on many 757 powerbacks back in the 1980's out of ATL, how do you explain this?
 
GQfluffy
Posts: 3072
Joined: Tue Apr 19, 2005 1:25 pm

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 2:47 pm

Quoting Crownvic (Reply 47):

Exactly. I'm not bashing Greasespot, I'm just curious how the C-17 (and I guess the 757 now) can powerback...
This isn't where I parked my car...
 
FoxBravo
Posts: 2769
Joined: Fri Nov 21, 2003 1:34 pm

RE: Northwest Using Reverse Thrust For Pushback

Tue Nov 29, 2005 11:12 pm

I think Greasespot meant that it was impossible for the engine to overheat in that way, not that it was impossible for the aircraft to power back.
Common sense is not so common. -Voltaire