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Fuel Planning - What do you use?


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Guest Brett Campany
Posted

It was one of the Nav briefing exercises that took me a while to get my head around. Even now it's a little confusing.

 

So what do you guys use, is there an easier way of calculating fuel and how do the members here who are instructors teach fuel calculations?

 

Look forward to hearing your responses.

 

 

Posted

Hi Brett.

 

This is probably obvious, but keep quizzing your instructor...learn as much as you can about the whizz wheel..ask any other instructors around the school lots of questions..I have recently moved to a busier school while i do the GA stuff, and its been great to have other qualified people to squeeze info out of.I dont care if im a pain in the butt, im gonna keep on asking!the fact is they are a wealth of information in the air and on the ground and i have much to learn from all of them.:big_grin:

 

Do you use a flight planning sheet for you navs?? It will hopefully come down to your whiz wheel, distance, time, your fixed reserve and the amount your plane burns per hour.If theres something ive missed apologies..

 

In the Tecnam i know it burns approx 20 litres per hour and it hold 90 litres so that gives it an endurance of 4.5 hours(270 minutes).then its just a matter of working out how many minutes i will be in the air on my nav after doing all the distance/wind/GS calculations on the whizz wheel and then to finally work out the difference (safe margin we hope!) between full fuel and what im going to use including the reserve in minutes and litres.

 

Im not sure how clear that was, but it makes some sense to me..031_loopy.gif.e6c12871a67563904dadc7a0d20945bf.gif

 

 

Guest Brett Campany
Posted

Since learning how to use the wizz wheel through one of our FO's who has 16 years under him as a PPL instructor, I've been able to make the required calculations but I suppose it's all going to come down to frequent use of the wizz wheel and the flight plan sheet.

 

I'm far from being mathematically minded so the first few goes at fuel planning was really tough. Just going to have to do more of it!

 

 

Posted

One other thing is....I Always use the calculator!I dont know if you've read "fate is the hunter" by Ernest Gann, but he talks about the days of "happy guesswork" being over..Its a good point and a great read so far..good for passing the time on the ground:thumb_up:..

 

The point is i use a calculator for even simple sums..Its allowed in flight and in exams, so i say why not use it?

 

 

Guest Brett Campany
Posted
One other thing is....I Always use the calculator dont know if you've read "fate is the hunter" by Ernest Gann, but he talks about the days of "happy guesswork" being over..Its a good point and a great read so far..good for passing the time on the ground:thumb_up:..The point is i use a calculator for even simple sums..Its allowed in flight and in exams, so i say why not use it?

Oh god yes, the calculator is my best friend!!

 

 

Guest brentc
Posted

Fuel planning all about rates. Be able to double numbers and half them and you're half way there.

 

Always use a reasonableness check to check your wizz wheel results.

 

eg.

 

If you use 20 litres per hour.

 

2 hours is 40 litres.

 

120 knots is 2 miles a minute.

 

Therefore 240 miles is 120 minutes which is 2 hours, so 40 litres.

 

At 90 knots (say if you fly at 95, just use 90 for the check).

 

100 miles at 120 knots is 50 minutes.

 

100 miles at 60 knots is 100 minutes.

 

So 100 miles at 90 knots is around 75 minutes.

 

Therefore fuel is going to be 15 minutes more than an hour, so 20 litres plus 5 litres for the extra 15 minutes which is 1/4 of 20 litres.

 

I hope that makes sense!

 

 

Guest Brett Campany
Posted
Fuel planning all about rates. Be able to double numbers and half them and you're half way there.Always use a reasonableness check to check your wizz wheel results.

 

eg.

 

If you use 20 litres per hour.

 

2 hours is 40 litres.

 

120 knots is 2 miles a minute.

 

Therefore 240 miles is 120 minutes which is 2 hours, so 40 litres.

 

At 90 knots (say if you fly at 95, just use 90 for the check).

 

100 miles at 120 knots is 50 minutes.

 

100 miles at 60 knots is 100 minutes.

 

So 100 miles at 90 knots is around 75 minutes.

 

Therefore fuel is going to be 15 minutes more than an hour, so 20 litres plus 5 litres for the extra 15 minutes which is 1/4 of 20 litres.

 

I hope that makes sense!

That's it, I'm going for a beer!

 

 

Posted
That's it, I'm going for a beer!

LOL!

 

I suck at math but after my 3rd nav or so and some practice in FSX I really don't have to think about it too much about using it for the common things anymore. I love the whizz wheel. It is kind of hard to grasp to start off with but when you have used it a bit is is soooo much faster than using the electronic methods I have tried.

 

 

Posted

I'm only two nax-ex's ahead of you Brett. And because my grades were not the best at school, the day I turned 14 my parents decided to drag me out of school to help them on the farm, I'm struggling a bit. So the whizz wheel is my best friend, I'm not a whizz at it (sorry I couldn't help myself), but I use it instead of the electronic calculator when ever I can, just to get more fluent with it and understand how it works.

 

 

Posted

I haven't seen it mentioned but remember in flight check of fuel is also to catch when you are using more fuel than standard. It will help when engine burns more due to tunning or mixture. It also helps if you have a leak caused by things such as drain points getting stuck. Probably preaching to the choir but there you go.

 

 

Posted

Calculators.

 

Personally I don't like them because you have to get the decimal in the right place. You have to do a "reasonableness" check, mentally, also.

 

The "Wizz wheel" is only a circular slide rule, when you are doing fuel calculations. You have all the times for the various legs already worked out. If you put the 60 or 1 hour marker against the hourly rate of usage for you plane, you can easily read the corresponding amounts (fuel burn) against the appropriate time interval numbers.. Check the answers for reasonableness by any way you like. If you are doing a very thorough job you will use reduced climb speed as well as an increased fuel flow rate, for that portion of the flight, and similarly, using different figures for the sector involving the descent.. When you add all the time intervals up and you add all the fuel burn figures up, you then check the totals and find what the average rate of usage is. This an internal check to make sure that there is not a glaring error. If you allow a bit for taxi and some for the circuit and approach at your destination. The total so far will be the amount that will have been consumed from your tanks when you shut your engine down, (if it all goes to plan).

 

You should carry reserves, and that amount, a quantity, equates to time in the air which is up your sleeve if things don't go according to plan. Nev

 

 

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