View Full Version : A320: unusable fuel in center tank.

11th Nov 2015, 19:29
Imagine that the 2 center tanks fuel pumps are inop and there's 1500 kg of fuel remaining in the center tank. According to MEL, you can depart with the 1500 kg in your center tank, but they must must be considered part of the ZFW. That part is clear.

Of course, one has to take the index shift into account for this fuel. The only location I can think of to find what the index shift will be, is on the back of our company's manual loadsheet. I'd look at what index I get with wings full + 1500 kg in the center and compare that to the "full wings index" The difference between the two is the number I need.

And now the question: Is there any other document that could give me the index change for 1500 kg unusable fuel in the center tank? Has Airbus published that?

tubby linton
11th Nov 2015, 19:44
The Ops procedure in the MEL doesn't help you. I would imagine that their once was a table which showed the momemt movement for various tanks and levels. There certainly was one for the A300.Does it still exiat in the MMEL?

11th Nov 2015, 20:42
Try WBM (Weight and Balance Manual) Fig. 1-20-04E

11th Nov 2015, 20:48
Try WBM (Weight and Balance Manual) Fig. 1-20-04E
Never heard about such a manual. Could you scan it and send it to me, please?

11th Nov 2015, 21:34
Never heard about such a manual. In that case, and if in EASA land see your OM-B chapter 6 Mass and Balance. It is a mandatory item to be included there.

regards, FD.

tubby linton
11th Nov 2015, 21:44
It is not in my airlines or a few others in EASA land.

Fursty Ferret
11th Nov 2015, 22:48
It's in our load and balance manual.

Apparently the effect is -1.2 unit per 1000 kg for a 320.

12th Nov 2015, 00:28
TL several options then :O
- I misundarstand and/or make things up about the applicable EASA IR-OPS;
- You are not reading the books thoroughly enough;
- The OMs are nowhere near being EASA compliant;
- Some sort of formal trick is in place (separate W&B manual as with my outfit)
Which one is it?

Sabenaboy for Airbus OEM W&B see here: A320-WBM weight and balance manual ??????_split_1.pdf_?????_????_????_????_???? (http://data.air.cc/plus/view.php?aid=1590). Yet I think that may be besides your point. The company manual loadsheet, with its reverse prints etc. does not come out of thin air. Its form alone as well as loads of other essential data such as the fuel trim index table need to be formally written down somewhere by the operating airline and approved by NAA. Though some companies do not bother their pilots with numerous books; rather provide a simple table / laminated card instead, maybe yours too. Were do you go for the DOW / DOI?

cheers, FD.

tubby linton
12th Nov 2015, 01:07
I have sent you a pm Flightdetent

12th Nov 2015, 03:56
In a standard FCOM a fuel index table for the center tank can be found under FCOM/PER/LOD/WBA/FIT/10/. It shows on our planes an index of -2 for 1500kg in the center tank.

The whole information about the load and trim sheet in my fcom is about 3 pages, not that much to go on, including a nice note on the load and trim sheet: "GENBERIC EXAMPLE, Irrelevant Data! Do Not Ue For Operational Purpose!". But then, the use of manual loadsheets is not an approved OPS procedure for us anyway. The approved manual W&B calculation is only via (iPad) software which does include all the information without writing it all out. But even that is considered non-standard as centralized load control is the standard method, of course they do use a software as well. Airbus FCOMs can be used instead of a standard OM B apparently, our boeing fleet uses a normal OM B, the airbus fleet the standard airbus documentation instead which does not include a W&B manual.

12th Nov 2015, 06:31
In a standard FCOM a fuel index table for the center tank can be found under FCOM/PER/LOD/WBA/FIT/10/

Thanks denti, found it!
(There's no such thing as a chapter 6 in my company OM-B)

12th Nov 2015, 21:59
Few quotes from the regs, not really relevant now to SB's question...

AMC1 ORO.MLR.100 (f) When compiling an OM, the operator may take advantage of the contents of other relevant documents. Material produced by the operator for the type-related part of the OM may be supplemented with, or substituted by, applicable parts of the aircraft flight manual (AFM) or, where such a document exists, by an aircraft operating manual produced by the manufacturer of the aircraft.

AMC1 ORO.MLR.100 (h) If the operator chooses to use material from another source in the OM, either the applicable material should be copied and included directly in the relevant part of the OM, or the OM should contain a reference to the appropriate section of that applicable material.

AMC3 ORO.MLR.100 1 The OM should contain at least the following information, where applicable, as relevant for the area and type of operation:

AMC3 ORO.MLR.100 1 B AIRCRAFT OPERATING MATTERS TYPE RELATED Taking account of the differences between types/classes, and variants of types, under the following headings:

Instructions and data for the calculation of the mass and balance including the following: (a) calculation system (e.g. index system);
(b) information and instructions for completion of mass and balance documentation, including manual and computer generated types;
(c) limiting masses and centre of gravity for the types, variants or individual aircraft used by the operator;
(d) dry operating mass and corresponding centre of gravity or index.

regards, FD.