Question 330766

[Mac]

According to feedback this question or versions of this question have appeared in every exam in the last few months. The question covers the calculation of possible additional fuel including the fuel penalty burnt en route by carrying the additional mass, but in this case the additional fuel is simply limited by the MTOM.
Several candidates have asked whether they should also add the taxi fuel to the total additional fuel possible because it would be burnt during taxi. This is not required in this question because despite being given the block and taxi fuels, the starting premise for the calculation is the Planned TOM 209500 versus the MTOM 220 300 so the taxi fuel has already been accounted for and we are merely calculating the extra fuel that can be carried at T/O that does not cause us to exceed MTOM or MLM.
Differently worded questions may require you to calculate maximum block fuel.

Given the following data:

MZFM 169 000 kg
MTOM 220 300 kg
MLM 179 000 kg
Maximum tank capacity 77 600 kg
Each 1000kg extra in mass incurs a fuel penalty of 350 kg
Block fuel 51 000kg
Planned Trip fuel 41 000 kg
Traffic load 39 000 kg
Taxy fuel 450 kg
Planned TOM 209 500kg

Calculate the maximum possible additional fuel:
Quadrant question: type in the answer.


There are 3 limitations to consider: MTOM, MLM, Tank capacity:

[toumas77]

Hi Mac, do you have the answer options? many thanks!

[binners]

Hi all,

This type of question is also worrying me as there doesn't seem to be a detailed guide about the correct methods to apply to answer. Is any one able to provide a guide to tackling them?

Binners

JJ Jones ?

[Mac]

Hi Guys, I have problems loading an attachment at present but if you look at Q ID 330766 and the answer you will find the solution.

Good luck.

[Transalp787]

Hi Can someone explain these types of questions in a bit more detail than found on BGS online? I'm ok with getting the maximum weights and stuff, but when it comes to applying the penalty, I cannot get my head around why we get 0.65 as a ratio and what we do with it from there??

[Mac]

The ratio is a method of deriving the fuel on arrival after the fuel penalty in carrying that additional fuel has been taken into account.

The fuel penalty is 350 kg per 1000 kg of additional fuel uplifted at the departure airfield.
That means for every additional 1000 kg uplifted at departure you will arrive at destination with 650 kg (1000 kg - 350 kg)
Thus we can use 0.650 to calculate the landing mass fuel per 1000 kg uplifted.

ie 10 000 kg uplifted x 0.65 = 6 500 kg at destination
17 000 kg uplifted x 0.65 = 11 050 kg at destination

Hope that helps

Mac

[Transalp787]

Thanks Mac! That clears the air