747400sp
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L1011 Tristar Taxing Before Starting All Engines

Wed Oct 29, 2008 2:34 am

I remember when there was still a lot of L1011 Tristars flying, after they push back, a lot of times you will hear the # 2 and 1 engine start up very loud clear, but then they taxi off and then down the taxi way you hear # 3 start. I remember both Delta and TWA did this, and I believe DC10s and 727 started all there engines before taxing, so why Tristar just start two, then start taxing and start the third engine in middle of taxing?
 
acNDTTech
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RE: L1011 Tristar Taxing Before Starting All Engines

Wed Oct 29, 2008 4:20 am

L-1011's taxied pretty fast if all 3 were running. I would guess that is a pretty good reason to taxi on 1 or 2.......to keep the speed down.
 
kimberlyRJ
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RE: L1011 Tristar Taxing Before Starting All Engines

Wed Oct 29, 2008 9:37 am

When I worked for TransWorld I only remember quite a few times when one of the engines were not started up until around five minutes after engines one and three had started.

Remember once being at JFK and the flight deck started all three engines before we pushed back – the surface of the stand was so water logged the tug could not push us back, even with engines at idle. The flight deck shut down one and three – still no good, so they were a little naughty and used reverse on two, it seemed to go the trick, to get us moving (as soon as we started moving the reverse thrust was cancelled). Must admit that’s the only time I have ever heard or seen this done…

Surely each engine powers essential equipment onboard the aircraft, air con packs, hydraulics etc – maybe on certain aircraft you need all three engines running to safely power the aircraft during taxi?

Kimberly.
 
typhaerion
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RE: L1011 Tristar Taxing Before Starting All Engines

Wed Oct 29, 2008 2:34 pm

This is done by a lot of airlines as a cost saving measure. You will see one engine taxi on twin engine jets all the time, with the second engine being started on the taxiway. Especially at the busier airports. The same principle applies to multi-engine jets, one or more will be left off to save fuel.

Quoting Kimberlyrj (Reply 2):
Must admit that's the only time I have ever heard or seen this done...

There are videos on the net of airplanes (DC-9s specifically) using thrust reversers instead of tugs to back away from the gate. Usually referred to as powerbacks, it was a lot more common 20 years ago when fuel was dirt cheap. These days it is non-existant. I would check youtube for this, or do a search of the civ av forum because I know it was discussed there.
For some, the sky is the limit. For us, it is only the beginning... -- Jack Hunt
 
Soku39
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RE: L1011 Tristar Taxing Before Starting All Engines

Wed Oct 29, 2008 3:41 pm



Quoting Typhaerion (Reply 3):
There are videos on the net of airplanes (DC-9s specifically) using thrust reversers instead of tugs to back away from the gate.

Just because a procedure is approved for one plane doesn't mean it is for another. A DC-9s engines are higher and less powerful than the 1 and 3 on a tristar, thus less likely to pull FOD off the ramp. If that Tristar crew wrecked an engine, or something happened during that push they'd be in the chief pilots office explaining why they "made up" a procedure, unless of course power backs in Tristars are approved, a couple people on here should know.  Smile
The Ohio Player
 
mandala499
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RE: L1011 Tristar Taxing Before Starting All Engines

Wed Oct 29, 2008 4:59 pm



Quoting 747400sp (Thread starter):
I remember when there was still a lot of L1011 Tristars flying, after they push back, a lot of times you will hear the # 2 and 1 engine start up very loud clear, but then they taxi off and then down the taxi way you hear # 3 start. I remember both Delta and TWA did this, and I believe DC10s and 727 started all there engines before taxing, so why Tristar just start two, then start taxing and start the third engine in middle of taxing?

Back in those days, fuel was "cheap", so fuel savings wasn't the reason as far as I remember.
The reason in a lot of cases, was jet blast...

If you pushed back from a cul-de-sac with the back towards the terminal building... starting the #2 engine was a bit of a no-no... especially if you're near the building... Why? The terminal floor (read: lots of glass) is at or just above the height of the main deck of the Tristar... for the DC10, the engines are higher, and the 727, lower than the floor and windows of the terminal...

If you pushed back and there's nothing behind you for >100m, heck, just start #2 as well...
There have been cases where DC10 also left #2 off until you're away from the terminal...

The other thing is, if there's another widebody right behind your aircraft, starting #2 could cause a mess *grin*...

Plus, the RB211 for the Tristar was pretty smoky on the start... have a body height plume of smoke at the height of the terminal floor in view of people probably startled a few people if you start #2.

Now, it's either that or the book I read 20 years ago was telling me lies... but hey, I could be wrong...  Smile
When losing situational awareness, pray Cumulus Granitus isn't nearby !
 
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litz
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RE: L1011 Tristar Taxing Before Starting All Engines

Wed Oct 29, 2008 5:19 pm



Quoting Soku39 (Reply 4):
Just because a procedure is approved for one plane doesn't mean it is for another. A DC-9s engines are higher and less powerful than the 1 and 3 on a tristar, thus less likely to pull FOD off the ramp. If that Tristar crew wrecked an engine, or something happened during that push they'd be in the chief pilots office explaining why they "made up" a procedure, unless of course power backs in Tristars are approved, a couple people on here should know.

Delta proved quite conclusively the ability of the Tristar's engines to suck FOD :



Story on http://www.aviationpics.de/fod/fod.html

- litz
 
typhaerion
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RE: L1011 Tristar Taxing Before Starting All Engines

Wed Oct 29, 2008 8:38 pm



Quoting Soku39 (Reply 4):
be in the chief pilots office explaining why they "made up" a procedure

No doubt. I didn't mean to imply that it was approved, proper, or even common for any plane type. In fact, I have not heard of any other type doing it. You really need clamshells for that to work great anyway. I just wanted to make mention that I had heard of it before and it used to be more common.

Quoting Mandala499 (Reply 5):
Plus, the RB211 for the Tristar was pretty smoky on the start...

You can say that again. Though it was a good kind of smoke, the kind that lets you know shes alive and kickin. I miss those starts from my days at TZ. Used to watch them at IND all the time.

Quoting Litz (Reply 6):
Delta proved quite conclusively the ability of the Tristar's engines to suck FOD :

First off, I dont know how you could call that FOD. The object is not foreign. Seriously. Maybe OD, but not FOD. And how do you know they weren't testing a new way to carry more cargo on their TriStars?  Wink
For some, the sky is the limit. For us, it is only the beginning... -- Jack Hunt

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