× Welcome to the CPL Navigation question and answer forum. Please feel free to post your questions but more importantly also suggest answers for your forum colleagues. Bob himself or one of the other tutors will get to your question as soon as we can.

## Exam questions

• danparker86
• Topic Author

### danparker86 replied the topic: Re: Exam questions

Hi guys,

Another query I have regarding fuel, let's say for example I was trying to find the fuel available for a flight, from what I understand you would take the total flight fuel in tanks then subtract the reserve and taxi and holding fuel then divide by 1.15 to get the reserve.

Why is it that when finding the fuel required I follow a system like this

Flight fuel + holding fuel x 1.15
+fixed reserve
+taxi reserve

But when finding the flight fuel available Shouldn't I reverse the system used above? Like this
Total fuel
Flight fuel - holding fuel / 1.15
- fixed reserve
- taxi reserve

In the book is says I should do this

Total fuel
- flight fuel
-holding fuel
- fixed reserve
- taxi fuel
Then divide by 1.15....

If anyone can clear this up for me it would be great!

Thanks alot guys

-Dan Parker

• Posts: 1962

### bobtait replied the topic: Re: Exam questions

Dan

The variable reserve applies only to the actual flight fuel and the fuel to the alternate [if required]. You do not apply the 15% variable reserve to the holding, fixed reserve or taxi fuel. Therefore to find the total fuel required you do this:

Fuel required = flight fuel + alternate fuel [if required] x 1.15. That looks after the variable reserve. Then add the fixed reserve, holding [if required] and taxi.

To go the other way and find the flight fuel available you do this:
Flight fuel available = Total fuel at start-up - taxi - fixed reserve - holding. That takes care of everything except the variable reserve. So you then divide the remainder by 1.15 and that removes the variable reserve leaving the flight fuel available.

In your worked example you are including the holding fuel as thought it was flight fuel. That is not correct.

• danparker86
• Topic Author

### danparker86 replied the topic: Re: Exam questions

Thanks Bob that really seems easy when you break it down like that for me really appreciate the help!

Cheers

-Dan Parker