singel09
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Taxi On One Engine A Fuel Saver?

Fri Mar 06, 2009 9:59 pm

All,

during my very regular visits to airports and flying weekly, I was thinking:

why, as to save fuel, don't the aircraft taxi on one engine ( on a 2 engine bird) or at least the minimum number required to taxi?

I have seen not too many examples of jest taxiing on one engine; I was on a KLM 737 recently, where the number 2 engine was shut down just after vacating runway.

I remember many ATR42/72 pilots taxiing on one engine?

Is this at all an option, or does a plane need all the engines running?

Thanks for any insight.

Maurice
 
ikramerica
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RE: Taxi On One Engine A Fuel Saver?

Fri Mar 06, 2009 10:08 pm

DL has done this on every trip I've been on recently. It really sucks on the MD80, because they seem to skimp out on the air conditioning during the 1 engine taxi, getting everyone all sweaty and complaining, then fire up the second engine and the AC comes on too strong and makes you cold.
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QANTAS747-438
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RE: Taxi On One Engine A Fuel Saver?

Fri Mar 06, 2009 10:10 pm

WN does it all the time. We taxi on one engine in an effort to pinch every penny, which I am in favor of. However, I was talking with a WN MX guy who said that it's pointless. When you're on two engines you use X amount of power. When you shut one down and use the other for taxiing, then that engine has to nearly double up on the power (especially from a dead stop) - and so it's kind of unneccessary. Sound wise, though, it's very noticeable... much quieter.
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ikramerica
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RE: Taxi On One Engine A Fuel Saver?

Fri Mar 06, 2009 10:16 pm



Quoting QANTAS747-438 (Reply 2):
Sound wise, though, it's very noticeable... much quieter

And it's probably marginally better for the engines. I can't imagine it's much of a difference between spooling up a single engine at nearly double the idle in 'stop and go' traffic, and spooling it up at normal for this kind of work. So one engine basically doesn't have any extra impact, and the other engine gets to remain shut down and doesn't have that wear put on it at all...
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Mir
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RE: Taxi On One Engine A Fuel Saver?

Fri Mar 06, 2009 10:25 pm



Quoting QANTAS747-438 (Reply 2):
However, I was talking with a WN MX guy who said that it's pointless. When you're on two engines you use X amount of power. When you shut one down and use the other for taxiing, then that engine has to nearly double up on the power

True, but at lighter weights one engine has enough thrust to get the airplane moving easily, and using just one engine for taxi makes sense. At heavy weights, you need both engines running.

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HeavyMX1
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RE: Taxi On One Engine A Fuel Saver?

Fri Mar 06, 2009 10:52 pm

Just got back from a CFM class and the instructor said that they are starting to see engine trends deteriorating before schedule and have attributed it to the practice on taxing in with one engine after landing. Apparently they are being shut down before the required cool down time..i.e. as soon as they exit the active... and they have been noticing accelerated disparities in fuel comsuption and EGT/TGT.
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KELPkid
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 12:20 am



Quoting Ikramerica (Reply 3):
And it's probably marginally better for the engines. I can't imagine it's much of a difference between spooling up a single engine at nearly double the idle in 'stop and go' traffic, and spooling it up at normal for this kind of work.

At the very least, you will have one engine accumulating a few more hours per month than the other (not really that big a deal, as airlines don't usually change engines in shipsets, except in a dual flameout involving bird strikes...  Wink ).

At the worst, you will see:

Quoting HeavyMx1 (Reply 5):

Just got back from a CFM class and the instructor said that they are starting to see engine trends deteriorating before schedule and have attributed it to the practice on taxing in with one engine after landing. Apparently they are being shut down before the required cool down time..i.e. as soon as they exit the active... and they have been noticing accelerated disparities in fuel comsuption and EGT/TGT.

Hopefully, the pilot and F/O will be mindful of these kind of operational limitations...

I flew on an OO CRJ-200 in 2006 from DEN to RAP, and was suprised when we taxied out on one, and didn't fire up the second engine until we were about two planes back from the runway in the conga line...I guess the CF-34 doesn't require that much warm-up time  Smile I also didn't know the CRJ was a regular candidate for single-engined taxis.
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411A
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 12:34 am

With the Lockheed tri-motor I fly now, we taxi with two engines operating all the time (if very light, taxi on number two engine only), and start remaining engines approaching the runway.
Does make a difference when fuel is short.
Economical, too.
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A10WARTHOG
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 12:37 am

When I was moving ERJ, we tried one engine and two engine taxi to see which one you used more fuel on. We ended up burning the same amount of fuel.
So normally we taxi with both engines, but if you know some work was being performed on one engine, we would only start the opposite engine and do a single engine taxi.
 
vandenheuvel
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 1:28 pm

If there is a long line for take-off, i think it saves quiet some fuel. The engines are on idle there anyway.
 
boeing767mech
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 1:40 pm



Quoting 411A (Reply 7):
With the Lockheed tri-motor I fly now, we taxi with two engines operating all the time (if very light, taxi on number two engine only), and start remaining engines approaching the runway.
Does make a difference when fuel is short.
Economical, too.
Follow the checklist for best results.

We used to have DC-10 pilots that would do that, they would light off the #2 engine just before turning onto the runway. was get for overtime because they would light off the engine and then pour the fuel to it before the engine had time to warm up the oil, causing the bearings to seize up.

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CrimsonNL
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 5:10 pm

It saves fuel yes, but if after a long taxi to the active you find out that #2 is not starting its a long taxi back as well!
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airbuster
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 5:44 pm

saves fuel, if shut down at 18R in AMS and taxi to the gate, IIRC you save about 10 - 20 kilo's...and KLC will be starting with the 1 engine taxi out procedure this summer, the argument of what if the engine doesn't start at the RWY is not so strong because engine starts are successful 99% of the time. in the last 3 years of flying jets i have had 1 hung start!

The only factor you have to consider is basically the engine warm up time needed with cold oil temperatures to be observed, this can be up to 4 minutes.

AB
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WPIAeroGuy
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 10:22 pm



Quoting QANTAS747-438 (Reply 2):
When you're on two engines you use X amount of power. When you shut one down and use the other for taxiing, then that engine has to nearly double up on the power (especially from a dead stop) - and so it's kind of unneccessary

Thats not neccessarily true because the engines use fuel just to idle, so any time the airplane stops you're idling two engines instead of just one.
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pilotpip
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 07, 2009 11:14 pm

We taxi the 170 on one engine all the time. They burn about 500pph a side at idle. When you're sitting on the ground for 30 minutes at ATL or ORD moving up in line it makes much more sense to burn 300 pounds than 600. After landing we'll shut one down on taxi in if the taxi is longer than 2 minutes required for cool down per GE.
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HAWK21M
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RE: Taxi On One Engine A Fuel Saver?

Sun Mar 08, 2009 6:22 am

Serves the purpose for long duration holding to get a gate/bay.Although the taxiing thereafter would need more than Idle to low thrust.
On landing minimum two minutes are provided as cooling before one engine is shut,but this also depends on the company SOP.
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AirframeAS
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RE: Taxi On One Engine A Fuel Saver?

Mon Mar 09, 2009 6:30 pm

At F9, on my last flight to SEA last week, we taxied to runway 25 in DEN on one engine. I don't know how long we have been doing this but this is the first time I have seen us do this.
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PGNCS
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RE: Taxi On One Engine A Fuel Saver?

Tue Mar 10, 2009 5:49 pm



Quoting WPIAeroGuy (Reply 13):
Quoting QANTAS747-438 (Reply 2):
When you're on two engines you use X amount of power. When you shut one down and use the other for taxiing, then that engine has to nearly double up on the power (especially from a dead stop) - and so it's kind of unneccessary

Thats not neccessarily true because the engines use fuel just to idle, so any time the airplane stops you're idling two engines instead of just one.

Correct WPI. Much of our taxiing time is spent stopped. The second engine does nothing for us then except needlessly burning fuel. There ARE times taxiing on all engines is warranted: contaminated/slippery taxiways, high gross weight, tight ramps, complex taxi clearances and/or bad weather, and of course to meet whatever operational limitations are required for warmup and cooldown; otherwise it's generally a net waste of fuel.
 
A333TS
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RE: Taxi On One Engine A Fuel Saver?

Tue Mar 10, 2009 9:55 pm

I spoke to TS pilot and he said that they can save as much as 200lb of fuel if taxiing on one engine. On the other hand he said that during rainy or snowy days taxiing with one engine is tougher especially during turns(I guess having an outside engine helps to make a tighter turn).

A333TS
 
Pihero
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RE: Taxi On One Engine A Fuel Saver?

Tue Mar 10, 2009 10:59 pm

Put it this way : Saving 20 kg of fuel at very sector, for a fleet of 100 airplanes doing each 8 flights a day saves...16 tons per day.
or 5840 tons per year, close to two million USG.
Do your maths, considering that at big airports, that value of 20 kg saved is vastly pessimistic.

And yes, taxiing-in on one engine is SOP.
As someone said, follow the check-list (that should include the cooling/stabilisation time).
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KAUSpilot
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RE: Taxi On One Engine A Fuel Saver?

Wed Mar 11, 2009 5:15 am

Single Engine Taxi is SOP where I fly, except for very short taxis. We are required to run the engines for 2 minutes prior to takeoff for warm engines or 4 minutes for cold engines. Our after-landing engine shutdown time was recently increased from 1 minute to 2 minutes minimum, 3-4 minutes preferred. I believe this was one due to a combination of decresing fuel costs and data from rolls royce indicating negative side effects of the 1 minute shutdowns.
 
pilotpip
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RE: Taxi On One Engine A Fuel Saver?

Wed Mar 11, 2009 6:33 am

As some have stated, there are times that we can't do it. Per our POH, these include braking action less than good, turning out from a gate (IE, no pushback), short taxi and of course, at the discretion of the captain.
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gkirk
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RE: Taxi On One Engine A Fuel Saver?

Wed Mar 11, 2009 8:48 am

Wouldn't you have to use slightly more thrust using one engine thus possibly negating any fuel savings anyway?
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David L
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RE: Taxi On One Engine A Fuel Saver?

Wed Mar 11, 2009 10:40 am



Quoting Gkirk (Reply 22):
Wouldn't you have to use slightly more thrust using one engine thus possibly negating any fuel savings anyway?

While more than idle thrust is required, yes, but, as pointed out above, a significant portion of the taxiing time is spent with the engine(s) at idle thrust and having one engine at idle burns less fuel than two at idle.
 
CosmicCruiser
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RE: Taxi On One Engine A Fuel Saver?

Wed Mar 11, 2009 2:48 pm

Obviously Fedex thinks it saves fuel because we only started it when fuel costs went thru the roof. You still must observe eng. temp, min idle parameters and crowded/ cluttered ramps, etc but as they calculated if each jet saves only 200 lbs a flight over the fleet look what you saved. We do it both out and in.
 
vc10
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RE: Taxi On One Engine A Fuel Saver?

Wed Mar 11, 2009 3:31 pm

Perhaps a very good reason for "taxi in" with an engine shut down is to save the brakes from wear, and if you have a short turn around, from getting to hot, which just might help when planning the next take off.

On Concorde two engines were shut down for taxi in, not really for fuel efficiency but to save the brakes and reduce braking so as to improve the comfort of the passengers.

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pilotpip
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RE: Taxi On One Engine A Fuel Saver?

Wed Mar 11, 2009 5:36 pm



Quoting Gkirk (Reply 22):
Wouldn't you have to use slightly more thrust using one engine thus possibly negating any fuel savings anyway?

Once your moving you don't need much thrust. On one engine, yes you need a little more to get rolling (break away thrust) but once you are you really don't need any because of the inertia of a hundred thousand pounds rolling forward. The 30 seconds of increased thrust is overcome by the few minutes of one engine being at idle versus two or more.
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HAWK21M
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RE: Taxi On One Engine A Fuel Saver?

Thu Mar 12, 2009 9:13 am

Also it helps to have the Outboard Engine in a turn running for Twin engined craft,though not necessary if one is willing to burn more fuel.
regds
MEL
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Pihero
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 14, 2009 2:26 am



Quoting HAWK21M (Reply 27):
Also it helps to have the Outboard Engine in a turn running for Twin engined craft

Not really if you have the requiored ground speed.
As a matter of fact, it is all about anticipation : get the speed above 10 kt and you have no problem with normal turns.
On the other hand, if you enter a cramped apron (LHR-style) where you'd require a final tight turn, one engine taxi could be rather dangerous for the people and equipment behind you as you'd need a lot more thrust on your remaining engine.
In that sort of condition, I keep all my engines running.
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AirframeAS
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 14, 2009 9:15 pm

On a D10/M11, would the tail engine be the engine to do the taxiing part? Or would you need the other engines too?
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CosmicCruiser
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RE: Taxi On One Engine A Fuel Saver?

Sat Mar 14, 2009 9:34 pm



Quoting AirframeAS (Reply 29):
On a D10/M11, would the tail engine be the engine to do the taxiing part? Or would you need the other engines too?

We taxi on 1 & 3 and delay the start for #2. This gives you symetrical thrust while taxiing and also the brakes are powered by hyd sys #1 & #3..
 
jamotcx
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RE: Taxi On One Engine A Fuel Saver?

Mon Mar 16, 2009 3:53 pm



Quoting Gkirk (Reply 22):
Wouldn't you have to use slightly more thrust using one engine thus possibly negating any fuel savings anyway?

Example on IAE V2500's on ground idle power approx 400kg/hr. Therefore about 800kg/hr taxiing round on 2 engines.

For single engine taxi we start the apu approx 40kg/hr and cut one engine loosing 400kg/hr.

As long as we dont have to stop we do need to apply extra thrust to keep us rolling. Even then I've monitored the fuel flow as we apply thrust to start moving again and never seen it above 700kg/hr and then its back at idle as soon as we "breakaway."

The only prob with the V2500's is the warm up (5mins) and cool down (3mins) times which mean normally by the time to shut one down we are already on stand at most places in europe.
 
AirframeAS
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RE: Taxi On One Engine A Fuel Saver?

Mon Mar 16, 2009 9:59 pm



Quoting CosmicCruiser (Reply 30):
We taxi on 1 & 3 and delay the start for #2. This gives you symetrical thrust while taxiing and also the brakes are powered by hyd sys #1 & #3..

Makes sense now, thanks!
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lightsaber
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RE: Taxi On One Engine A Fuel Saver?

Sun Mar 22, 2009 3:59 pm



Quoting QANTAS747-438 (Reply 2):
When you're on two engines you use X amount of power. When you shut one down and use the other for taxiing, then that engine has to nearly double up on the power (especially from a dead stop) - and so it's kind of unneccessary.

You do not need double the fuel for double the power. Engines are very inefficient at low throttle points. While there will be a point with a wear threshold, as long as you stay below that, it should be far more economical on one engine.

As already noted:

Quoting Jamotcx (Reply 31):
Example on IAE V2500's on ground idle power approx 400kg/hr. Therefore about 800kg/hr taxiing round on 2 engines.

For single engine taxi we start the apu approx 40kg/hr and cut one engine loosing 400kg/hr.

As long as we dont have to stop we do need to apply extra thrust to keep us rolling. Even then I've monitored the fuel flow as we apply thrust to start moving again and never seen it above 700kg/hr and then its back at idle as soon as we "breakaway."

If you get above the fuel burn of 2X engines idling... that's quite a bit of ground thrust!

Quoting HeavyMx1 (Reply 5):
Apparently they are being shut down before the required cool down time..

As already noted, easy to fix with training and procedures.

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HAWK21M
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RE: Taxi On One Engine A Fuel Saver?

Mon Mar 23, 2009 7:30 am



Quoting Lightsaber (Reply 33):
As already noted, easy to fix with training and procedures.

The Famous Three step policy to succeed:-
1.Identify the problem.
2.List the solutions.
3.Implement the solutions.

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thegreatRDU
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RE: Taxi On One Engine A Fuel Saver?

Wed Apr 07, 2010 9:44 pm

What about on a propeller aircraft like a Q400?
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CosmicCruiser
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 08, 2010 12:03 am

Quoting Boeing767mech (Reply 10):
they would light off the #2 engine just before turning onto the runway. was get for overtime because they would light off the engine and then pour the fuel to it before the engine had time to warm up the oil, causing the bearings to seize up.

that's why you observe the warm up limits before going to T/O power. If time limits apply do a 2 eng taxi, if not start 3.
 
goboeing
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 08, 2010 2:05 am

Like pilotpip I fly the E-170 series.

Single engine taxi at my company has us taxi out with the APU running as opposed to doing a cross-bleed start for the second engine.

The engines burn about 500-600pph each at idle.

The APU burns about 300-400pph.

So with the APU and one engine you're burning 800-900pph at idle. Factor in the occasional 5-20 seconds of thrust to get moving to a reasonable speed and would think it ends up being 900-1000pph. That is within a hundred pounds of the burn for both engines on.

Knowing that, and knowing that it's usually less than five minutes from engine start to second engine start when single engine taxiing, it's usually only a savings of 10-40 pounds of fuel.

This equals one third the amount that we burn while waiting for the ramp crew to show up to park us at the end of the flight.

Until the lack of ramp crew issue changes, I am convinced that fuel savings really is not a priority at this particular operation and so I am opposed to single engine taxi at my company on the departure taxi.
 
pilotpip
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 08, 2010 2:32 am

It adds up really fast Boeing.

Turning off a bleed while sitting saved us from missing an EDCT a couple days ago at ORD. We took off right at min fuel.
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hercppmx
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 08, 2010 3:47 am

Since your break away thrust for one engine vs. two would require the running engine to be given a little more power I wonder if this would have a negative effect on the turbine after awhile?
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kcrwflyer
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 08, 2010 4:28 am

Quoting thegreatRDU (Reply 35):
What about on a propeller aircraft like a Q400?

Good question. I often see Colgan flights taxiing with one engine feathered and the other providing thrust... I'm not sure how much fuel that saves since both engines are technically "on".
 
musang
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 08, 2010 10:22 am

Quoting QANTAS747-438 (Reply 2):
talking with a WN MX guy who said that it's pointless. When you're on two engines you use X amount of power. When you shut one down and use the other for taxiing, then that engine has to nearly double up on the power (especially from a dead stop)

Disagree. On 737 classics we may need a bit of thrust on one engine to move from stationary but only momentarily. Once rolling idle on one is sufficient. We rarely have to stop on the way to the gate.

[quote=David L,reply=23]
Quoting Gkirk (Reply 22):
Wouldn't you have to use slightly more thrust using one engine thus possibly negating any fuel savings anyway?

On two engines a 737 will, on a long taxi, accelerate to the point where it needs braking to control speed. It can get to 25 knots + easily, and 15 knots is the absolute max I would go around 90 degree turns at. On one engine it trundles along nicely with minimal braking, if any, needed when a turn arrives.

Due to long delays at holding points I would say there is even more potential for fuel saving with single engine taxi out, but my airline, being highly conservative, hasn't yet bitten the bullet regarding the required SOP/checklist philosophy mindset change required. Last time it was looked at the rejection was due to the chance of distractions causing things to be missed, there being so much going during the taxi out especially if there's no delay at the hold.

Regards - musang
 
vandenheuvel
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 08, 2010 12:49 pm

Quoting KcrwFlyer (Reply 40):
I'm not sure how much fuel that saves since both engines are technically "on".

IIRC on the F50 this is done to minimize thrust. As two engines will provide too much power for a low taxi speed. If it's a long taxi, I believe they don't even start one of their engines. Maybe it's a similair thing on the Q400, any ideas about this?

I know it's the same thing as mentioned above, yet I don't believe this is the reason for starting only one engine on the 737.

[Edited 2010-04-08 05:51:18]
 
KingFriday013
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 08, 2010 11:42 pm

Quoting CrimsonNL (Reply 11):
It saves fuel yes, but if after a long taxi to the active you find out that #2 is not starting its a long taxi back as well!
Quoting Airbuster (Reply 12):
the argument of what if the engine doesn't start at the RWY is not so strong because engine starts are successful 99% of the time. in the last 3 years of flying jets i have had 1 hung start!

I notice that on Delta, they usually leave one engine off for taxi; on Delta Connection carriers it's hit or miss (from what I've experienced, Comair does it, Freedom Air doesn't, etc.). US Airways Express carriers usually start both at the gate; this was a good thing on a flight I took on Air Wisconsin back in October, as the engine wouldn't start (we even started taxiing so they could try a cross bleed start or something like that), and we ultimately had an aircraft swap.

Quoting thegreatRDU (Reply 35):
What about on a propeller aircraft like a Q400?

It's hit or miss. I remember on Air Canada a while back, they feathered an engine for part of the way while the other was on. On Piedmont Airlines (US Express carrier), they usually start both consecutively, but once we taxied on one engine to a holding zone since we missed our slot, and they shut off the engine until we could leave again. Those were all -100s. I was on a Colgan Q400 once, and I don't remember what they did.

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thegreatRDU
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 15, 2010 1:01 am

Quoting KingFriday013 (Reply 43):
I was on a Colgan Q400 once, and I don't remember what they did.

From what I've seen at RDU they taxi on both...
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packcheer
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RE: Taxi On One Engine A Fuel Saver?

Thu Apr 15, 2010 3:24 pm

I don't know that RDU is a good case study for one engine taxi. With the way the Terminals are set up in relation to the taxi ways and runways, I can't see any plane taxi on one and having the time to start it and let it warm up once they are out there.

At RDU it's prolly best to start both and go. Taxi's are usually fairly short
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sstsomeday
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RE: Taxi On One Engine A Fuel Saver?

Fri Apr 16, 2010 3:23 am

Quoting PGNCS (Reply 17):
Much of our taxiing time is spent stopped. The second engine does nothing for us then except needlessly burning fuel. There ARE times taxiing on all engines is warranted: contaminated/slippery taxiways, high gross weight, tight ramps, complex taxi clearances and/or bad weather, and of course to meet whatever operational limitations are required for warmup and cooldown; otherwise it's generally a net waste of fuel.

I understood that a full stop stop, followed by a tight turn in the direction of the single running engine can be difficult or impossible on some twins. Does a pilot have to consider his likely route to the active or to the gate before he/she decides to make a go of it on one engine?
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musang
Posts: 788
Joined: Sun Apr 08, 2001 4:11 am

RE: Taxi On One Engine A Fuel Saver?

Sun Apr 18, 2010 8:23 pm

Correct on both counts - in the first, as long as its got moving ahead before the turn is attempted, it will handle it as long as its not too tight. How tight? That comes with experience, intuition and experimentation!

On the second point we only shut one down inbound, and there is usually a decision made based on the final turn into the gate. Many insist on a tight, small radius turn into the parking line, not started until the flight deck is abeam the line, in which case the outside engine better be the one still running. However such tight turns are rarely necessary for us and a wider radius turn can easily be done with either engine shut down.

Shutting one down at high weights is cause for consideration, but we very rarely have to stop while taxiing in. If a stop is anticipated, slow down so as to try to avoid stopping. At airports we visit regularly we know if any taxiways or parking stands are sloped and these would be considered also.

The other issue is the laser ranging parking aids on the gates at home base, rediculously sensitive and a completely unnecessary replacement for the primitive, visual parking alignment systems and mirrors which preceded them (which were perfectly adequate). We are campaigning to get the mirrors put back, because the laser systems usually stop us a few inches short or too far, which causes chaos on the nose-loader airbridges (the ones which go in and out, but not side-to-side, those being known as apron drive airbridges). This is because on classic 737s there's not much space between the pitot tubes and the forward edge of the opened door, to slot the airbridge canopy in. So it must be parked with an accuracy of about 4 inches and the hi-tech guidance systems can't handle it. I usually stop a foot short then look to the agent in the airbridge, who gives final placement with hand signals.

The problem is that on one engine, if one hasn't got the energy management just right, one stops early and needs a lot of revs to move the last few inches, which is (a) potentially dangerous and at best, noisy, to an inattentive ground guy, and (b) increases the chance of sucking debris in.

Bottom line - if on a stand with a nose-loader, probably best to keep them both running.

Regards - musang
 
thegreatRDU
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Joined: Tue Mar 07, 2006 10:47 am

RE: Taxi On One Engine A Fuel Saver?

Sun Apr 25, 2010 12:56 am

Quoting Packcheer (Reply 45):
At RDU it's prolly best to start both and go. Taxi's are usually fairly short

That's true the same goes for the Piedmont Dash 8's at GSO....
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kbpilot5
Posts: 13
Joined: Sun Sep 30, 2007 7:33 am

RE: Taxi On One Engine A Fuel Saver?

Mon May 10, 2010 2:22 am

Quoting thegreatRDU (Reply 48):
That's true the same goes for the Piedmont Dash 8's at gso....

Unless you taxi over to 5L  
I recently saw one taxing with one engine but I think they were going to sit somewhere.

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