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(EK) Disciplined for carrying fuel?

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(EK) Disciplined for carrying fuel?

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Old 3rd Apr 2010, 05:01
  #41 (permalink)  
 
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Errr...yes, but you will have the extra fuel instead of cargo at the other end...
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Old 3rd Apr 2010, 05:01
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This fuel thing could be eased a bit by some careful coordination and planning with DXB ATC.

We could keep the loading of extra fuel on ULR to a minimum by having ATC priority for those flights upon their return to DXB. In effect, no holding. We could relax a little on the worries regarding extra fuel on these particular flights. It would perhaps result in a more streamlined operation.

Thoughts?
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Old 3rd Apr 2010, 05:17
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Haha Pool... funny conclusion but better go straight off to bed after that indian night turn....
Maths.....
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Old 3rd Apr 2010, 05:42
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M-rat.
What is wrong with you, ya Habibi? Why apply logic and intelligent thought when EK don't respect or value the input of professional people?
The sad reality is that your excellent suggestion didn't come from a "manager". It comes from a pilot. What do they know about flying?
I wonder where our friend mana is? Would welcome his insight into this
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Old 3rd Apr 2010, 05:58
  #45 (permalink)  
 
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Errr...yes, but you will have the extra fuel instead of cargo at the other end...
Elementary, Watson! You determined that you needed the extra fuel to have the minimum you want at the other end. That's called fuel planning. With weight critical DPP, unfortunately, this sometimes means offloading payload.

Haha Pool... funny conclusion but better go straight off to bed after that indian night turn....
Maths...
I don't know what's funny about all this. Serious planning implies some payload restriction sometimes.
Without wanting to sound sarcastic, but it seems that some of the contributors have little experience with critical fuel/weight planning.

Why on earth does this remind me the "manas" and "5.5s"??
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Old 3rd Apr 2010, 06:50
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You mentioned it costs 3% to carry extra fuel? That is not even in the ball-park. On a typical........ say DXB-SYD flight, a Triple7 or Airbus burns almost 50% of the extra fuel it carries.! An extra tonne of fuel equates to only having 500kgs extra fuel upon arrival.
Not quite true. If you have a closer look at things you will find that you burn about 33% of the fuel you carry. If we carry 1 ton of cargo it will cost us around 500kg for the ulr flights. Same goes for fuel, if we want to arrive at destination with 1000kg of fuel we will need 500kg to carry it there. That is 33% not 50%.

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Old 3rd Apr 2010, 07:43
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Hmmm... Pool,

Following your reasoning, why do we bother loading fuel at all? We could just fill the fuel tanks with cargo!!

If you off-load a tonne of cargo to uplift a tonne of fuel, you will have about 500-600 kgs of that extra fuel left on arrival after a ULR (only 3-5 mins of fuel admittedly, but sometimes enough to reduce the 'pucker factor' and not have to commit to destination for a little longer!).

The point being chaps, if you think're gonna need it, put it on. I know of no-one that has been bought to task about extra fuel carried.
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Old 3rd Apr 2010, 08:05
  #48 (permalink)  
 
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Come on Oblaaspop, you know better.

Situation: MTOW and DDP. You decide you need some extra to cover parameters "X" and "Y". You will have to offload payload to the same amount. Weights remain the same, planned burn remains the same. Upon arrival you might still have the extra, or you will have used it (or parts) due to the foreseen additional parameters.
In this case you would have the TOTAL extra fuel you decided to uplift, as the burn on the flightplan covered MTOW already. So if you exchange payload for fuel you will have all of it at destination or decision point, unless .... the factors "X" or "Y" effectively happened and the uplifted extra was used. This would then leave you with the initial reserves and this is what the extra should be intended for.


I know of no-one that has been bought to task about extra fuel carried
Happened here though.
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Old 3rd Apr 2010, 11:34
  #49 (permalink)  
 
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If you off-load a tonne of cargo to uplift a tonne of fuel, you will have about 500-600 kgs of that extra fuel left on arrival after a ULR (only 3-5 mins of fuel admittedly, but sometimes enough to reduce the 'pucker factor' and not have to commit to destination for a little longer!)
.

Again not quite correct. If you exchange cargo for fuel, all other things being equal, you will arrive at destination with all of that fuel. Think about it. The 1000kg of cargo does not decrease during the flight, so why would a 1000kg of fuel reduce. This is a common error I see on the line at EK.

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Old 3rd Apr 2010, 12:30
  #50 (permalink)  
 
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Fuel Stuff

On Past Plans I Have Used There Is A Box Which Says Fod Or Fuel Overhead Destination... That Is Sort Of The Number That One Actually Wants To Know But Our Lidos Dont Actually Show It Unless You Do Some Of Your Own Maths Etc.

It Has A Min Fuel Line Against Each Waypoint But That Assumes You Are Burning All Your Contingency Etc.

Some Odd Maths In The Last Posts But I Always Thought That If You Swapped Payload For Fuel You Had The Fuel At The Destination...??

Or Did I Get My Maths/physics Bsc From Melbourne Uni By Corn Flake Package???

Wja
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Old 3rd Apr 2010, 17:56
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A757,

I think you miss my point, indeed if you dump a tonne of cargo and uplift a tonne of extra fuel, of course you will still have that full tonne of fuel available to you at the other end.

If you don't offload the cargo however, you will only have the 500-600 kgs left at the other end.

The common mistake being, is that some guys want to arrive at destination with X amount of holding/extra for 'mum' fuel, but don't take into account that they actually have to put 50% more than the extra they need on (for ULR anyway).

I don't really see what the problem is anyway..... If there is even a hint or whiff of misty conditions now in DXB, the company automatically put on a ludicrous amount of extra gas and will willingly offload cargo etc to achieve it! Out of PER last year, they wanted me to leave 4 staff pax behind due to being landing weight limited in DXB due to the extra fuel for fog they wanted me to carry......... I just upped the planned burn by a few hundred kgs and got them on and got home a few minutes earlier good old cost index 99, works every time

Just be sensible, and keep your head down while doing it, and no-one will be any the wiser..... I'm bloody sensible on every one of my flights, and I have never been quizzed!
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Old 3rd Apr 2010, 18:38
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oh...k...

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Old 4th Apr 2010, 01:31
  #53 (permalink)  
 
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Here some free tips to replace the guesswork:
The amount of extra fuel you put on will be burned by
what you find as extra fuel burn in the Lido Plan (good for +/- 3tons)
But if you ask the dispatcher to plan extra fuel, the
total fuel will include the burn for that.
It's always helpful to know your systems ;-)
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Old 4th Apr 2010, 06:32
  #54 (permalink)  
 
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Good point Schib...

Woodja 51, I had the same experience....Old Eagle flight plans used to have two ZFW corrections, one for ramp correction, used to correct for extra fuel to burn along the entire flight. The other was Landing correction, used if you wanted to have the extra fuel at destination for weather at destination for example. Of course, the Landing correction was higher but it was nice to have the two options and it showed the difference between burning the fuel enroute and having it still available at destination. If extra cargo was loaded as LMC, you would use the Ramp correction to account for the fuel to carry it the entire flight without needing any extra at destination.

The ZFW correction for LIDO is like the ramp correction, you need to account for the extra fuel required if you need it at destination.

Oblaaspop said, which is true...

"The common mistake being, is that some guys want to arrive at destination with X amount of holding/extra for 'mum' fuel, but don't take into account that they actually have to put 50% more than the extra they need on (for ULR anyway)."


Obaalspop said,

""I think you miss my point, indeed if you dump a tonne of cargo and uplift a tonne of extra fuel, of course you will still have that full tonne of fuel available to you at the other end."

This statement is not true. The tonne of cargo will weigh the same at destination, naturally, but the extra tonne fuel you carry some will be burned enroute, UNLESS you account for it in the fuel burn or carry extra fuel to account for that.

In any case, carry what you need and account for the extra fuel required if you need it, especially at DESTINATION.
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Old 4th Apr 2010, 07:26
  #55 (permalink)  
 
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Oblaaspop, first you wrote:

If you off-load a tonne of cargo to uplift a tonne of fuel, you will have about 500-600 kgs of that extra fuel left on arrival after a ULR
then you corrected:

I think you miss my point, indeed if you dump a tonne of cargo and uplift a tonne of extra fuel, of course you will still have that full tonne of fuel available to you at the other end
So you got it, finally. But now you have a worthy successor with Saltaire:

This statement is not true. The tonne of cargo will weigh the same at destination, naturally, but the extra tonne fuel you carry some will be burned enroute
Some of us should go over basics again, or they'll make us look real bad!!!!
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Old 4th Apr 2010, 08:25
  #56 (permalink)  
 
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Saltair said,

Obaalspop said,

""I think you miss my point, indeed if you dump a tonne of cargo and uplift a tonne of extra fuel, of course you will still have that full tonne of fuel available to you at the other end."

This statement is not true. The tonne of cargo will weigh the same at destination, naturally, but the extra tonne fuel you carry some will be burned enroute, UNLESS you account for it in the fuel burn or carry extra fuel to account for that.
The statement, stating the statement is not true, is not true. Saltair you are not adding extra weight to the aircraft if you REMOVE a ton of cargo and add a ton of fuel. The aircraft will weigh the same at take off therefore the fuel burn to destination will be the same in both cases. As a matter of fact, the case where you have the extra ton of fuel will actually burn less because the ton of fuel is pumped around the aircraft to optimize the C of G thereby saving fuel (airbus fuel system).

You must account for extra fuel burn only if the resulting take off weight is more than the original flight planned weight.

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Old 4th Apr 2010, 08:25
  #57 (permalink)  
 
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I'm so proud of my colleagues. Guys, just nut up and carry what you are comfortable with. Bottom line, it's your ass in the air and on the line. The safest and most conservative decision will always win in any aviation argument. Be commanders and tell them how its going to be, not the other way around.
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Old 4th Apr 2010, 08:40
  #58 (permalink)  
 
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MosEisley,

Dude, we are just talking. Take a pill.

SMA,

The EK pilots lost their dignity ages ago.

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Old 4th Apr 2010, 11:36
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I found some old notes, so maybe this may help a few people, myself included....two corrections here but concept is the same. EK CFP's would use the LNDG correction below.



9. Corrections to TRIP FUEL

CORR/1000 LNDG (L) and CORR/1000 RAMP (R). Initially Airpath computes the FUEL REQD for the planned ZFW then recalculates the TOTAL FUEL for the ZFW reduced by 3% or by 5 tonnes (whichever is less). The CORR/1000 RAMP value is the difference between the 2 derived TOTAL FUEL values divided by the difference between the 2 RAMP WTs. The CORR/1000 LNDG value is geometrically derived from CORR/1000 RAMP since the addition of an increment in aircraft weight requires a small addition to the fuel burn; that additional fuel when loaded also requires a small addition to the fuel burn and so on ad infinitum. Thus L = R/(1-R) and conversely R = L/(1+L).

At the planning stage, the aim is to modify the fuel values to arrive at destination with the same CFP fuel reserves after changes to ZFW or operational changes to Alternate or Holding fuel. Corrections to Contingency based on revised TRIP FUEL are not considered. The corrections are most easily understood by considering the necessary changes to the individual values in the fuel column and finally summing those values to yield a TOTAL FUEL. 5 examples are provided, the first 3 form the backbone of daily operations, the 4th applies purely to long haul and the 5th possibly at JNB/CNS but is included for completeness. Assume that CORR/1000 RAMP = .279 and CORR/1000 LNDG = .387:

Examples: 1 ADJUSTING TRIP FUEL FOR ZFW INCREASE:
ZFW has increased from the CFP value:
Multiply ZFW increase (say 2000kg) by LNDG: 2000kg x .387 = 774kg
This figure is the increased TRIP FUEL. This increase in TRIP FUEL causes an equal increase in TOTAL FUEL and will give the same planned arrival fuel.
The RAMP WT increase is the sum of the ZFW increase and the TRIP FUEL increase = 2774kg.
Cross check by multiplying the RAMP WT increase by RAMP: (2000 + 774)kg x .279 = 774kg
equally ADDITIONAL FUEL REQUIRED AT DESTINATION uses the same calculations since the aircraft is insensitive to its weight change being either ZFW or tankered fuel.

2 ADJUSTING TRIP FUEL FOR A ZFW DECREASE:
ZFW has decreased from CFP value:
Multiply ZFW reduction (say 2000kg) by the LNDG: 2000kg x 0.387 = 774kg
This figure is the reduced TRIP FUEL. This reduction in TRIP FUEL causes an equal reduction in TOTAL FUEL and will give the same planned arrival fuel.
The RAMP WT reduction is the ZFW reduction plus the TRIP FUEL reduction = 2774kg.
Cross check by multiplying the RAMP WT reduction by the RAMP: 2774kg x 0.279 = 774kg

3 ADJUSTING TRIP FUEL AFTER FINAL FUEL IS FIXED:
RAMP WT has changed due to (say) a drop in ZFW after fuelling was completed:
Multiply ZFW decrease (say 2000kg) by RAMP: 2000kg x .279 = 558kg
This figure is the decreased TRIP FUEL.
This reduction in TRIP FUEL does NOT affect the TOTAL FUEL and will give an increase in arrival fuel.
The converse applies for a ZFW increase after fuelling was completed.
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Old 4th Apr 2010, 13:31
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Saltaire

All correct, but if you switch payload for extra fuel, the flight plan trip values and weights remain exactly the same. The engines don't give a rats a$$ if they transport frozen lamb, live people or fuel.


As for MosEisley

Nice barking from the other side of the locked fence buddy! Wait until some AARchaic lunatic opens the fence and invites you in .... Are you even distantly familiar with this place?
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