ATPL Questions, (HELP!)

[Heli-Ice]

I am preparing for the JAR Flight Planning exam and plowing through some questions.
I may be a little bit thick but I can't seem to get the drift of this question and ask for your help please.

For a planned flight, calculate fuel as follows:

Flight time 2:42min. The reserve fuel, at any time, should not be less than 30% of trip fuel remaining. Block fuel 136kg. Taxi fuel 9kg. How many kg of fuel should remain after 2hrs flight?

a) 33kg trip & 10kg reserve,
b) 25kg trip & 8kg reserve,
c) 23kg trip & 10kg reserve,
d) 33kg trip & no reserve.

According to my resource the answer is b) but I get another result?

Hope someone can show me how this is calculated.

:confused:

[EGBKFLYER]

My thoughts go like this:

Block fuel = trip + taxi + reserve

At the threshold, you've burnt the taxi, leaving 127kg trip/ res fuel

127kg trip fuel = 1.3 x trip (because the question says so)

So trip fuel is 98kg near enough

Flight time is 2:42, in which time you burn 98kg, so after 2:00 you will have burnt 72kg, leaving 26kg + 30% (8kg) in the tanks

Closest answer is B...

[Send Clowns]

It's one of the dumbest exam questions I have seen (and with JAA, that's sayig something). Yours is not quite an exact rendition of the question (I will try to get you a better version of the exam question tomorrow. It is just as stupid) but here is my answer.

Take off with 127 kg for 162 minutes' (2 hours 42 minutes) flight. 98 kg is trip fuel, 29 kg reserve.

With 98 kg for 162 minutes you are expecting to use 0.605 per minute, so with 42 minutes remaining you need 25.4 kg trip fuel, and a minimum 7.6 kg reserve required, so (b) is ... well the figures you get from this calculation. Notice I didn't say "correct". Of course all 29 kg reserve should remain - if you only have 8 kg left then you're going to use all your reserve and run out of fuel as you land, not a situation usually approved of by the regulating authorities.

There are some people writing quesions who know f*** all about flying, and have the common sense of the common slug, and it really irritates me. However, you have to put up with being judged on your knowledge by the truly ignorant. Welcome to Europe.

Best of luck in the exam, feel free to contact me directly for a direct answer (sorry if this is a little too direct, but after a beer I really cannot cope with JAR bull'it).

Send Clowns
BCFT - some time Flight Planning instructor

[Send Clowns]

The best feedback I can give you for this type is:Planned Flight time : 3:06
Block fuel : 118 kg
Taxi fuel : 8 kg

Same detail, with reserve fuel rquired to be not less than 30% of remaining trip fuel at any time. Fuel remaining after 2 hours should be:

(a) 33 kg trip 11 kg reserve
(b) 39 kg trip no reserve
(c) 30 kg trip 9 kg reserve
(d) 27 kg trip 12 kg reserveNote that again the actual answer is not there, as the initial reserve fuel should, at that stage be intact. What they mean is "what is the minimum fuel required at that point?". Even then unless they state that the block fuel is minimum required they are not giving enough information!

Try this version, and I'll let you know whether you're right or not.

[Heli-Ice]

Thank you for your explanations.

Send clowns.

I think answer c) is the closest i can find for your example. What I am mostly confused about is that the taxi fuel is taken into this calculations? My memory, even though it is of the best sort available and preserved in spirits, doesn't have any recollections of being taught that.

What I think is the thing with the question is the "at any time" part. Some tricky little ba***rd somewhere inside the JAA temple of visdom must have come up with this great brain contaminating material.

On the other hand, it might just be silly me that should consider moving on to something else than flying because if one can't calculate easy things like this he shouldn't be able to find his way home.

Best to you all,

Heli-Ice

[EGBKFLYER]

So it looks like the conclusion is that it's a stupid question.

I think you're looking at it the right way HI - it's an academic exercise in calculating ratios and using them to extrapolate an answer. All exams are a game. Play the game and don't get angry at the rules - let the ground instructors do that (eh SC?!)

Understand the rules, play the game, pass the exam and move into the real world... don't sweat it. I wish you the best of luck and thanks for the revision!

EGBK

[Heli-Ice]

Thank you Flyer.

Like you said, its an exercise, mind exercise. The consequences (think I spelled it right?) are that I think my head has grown a little bigger over the last few days of all this knowledge gained and I need to buy a bigger baseball cap.

All I ever needed to know was to keep the pointy thing forward and play with the volume buttons. Problem is that there's no pointy thing on the front of the helicopter I fly, I'm still trying to figure out which way to go. :confused:

Later,

Heli-Ice

[Send Clowns]

Aye, EGBK :O

(c) is good. That is the answer they expect, Heli, the only one I can achieve with those figures! Taxi fuel is just that - used in taxiing. It must be subtracted from block fuel to find take-off fuel.

This is not even approaching being close to real fuel calculations. It is probably a mistranslation of an already poor question. I would be better presented to a maths class as a problem for people who don't know anything about correct fuel calculations, as your knowledge of aviation (a PPL being a prerequisite for the course) gets in the way rather than helping!

Fly a 109, that has a pointy end :D As well as being a very pretty helicopter (although not a patch on the seriously ugly Seaking, of course).