I have done a few practice exams from different websites and one that caught me out on both occasions were the following two questions. I'm really puzzled about this one and don't really understand where they got the answers from. I do understand the INTER/TEMPO thing with the buffer but

Just to note this will be helicopter Airlaw so helicopter minima will be used:

Class C/D: Cloud > SCT below 1500ft AGL OR Visibility < 8km
Class G: Cloud > SCT below 1000ft AGL OR Visibility < 3000m
TEMPO/INTER similar to aeroplane.

Question 1:

Refer TAF.

TAF YAFT 271800Z 2620/2708 34013KT 5000 FEW005 FEW008 BKN010
INTER 2702/2704 3000 SCT006 OVC010
TEMPO 2704/2706 2000 FEW002 SCT005 OVC010
RMK
T 22 23 23 24 Q 1011 1012 1009 1007

YAFT is outside controlled airspace and the use of Helicopter VMC is permitted at the aerodrome. An alternate aerodrome, with a TAF indicating CAVOK conditions all day, is located 35 minutes flying time away.

Assuming cruise fuel flow and holding fuel flow are similar rates, for a planned arrival time at YAFT of 270615Z the minimum additional alternate or holding fuel required is -

A 15 minutes holding fuel
B 45 minutes fuel to the alternate
C 30 minutes holding fuel
D 60 minutes holding fuel

The answer supplied was A. I selected D. Perhaps because the TEMPO's buffer ends 15min later than your planned arrival time?

Question 2

Refer TAF.

TAF YAFT 271800Z 2620/2708 34013KT 5000 FEW005 FEW008 BKN010
INTER 2702/2704 3000 SCT006 OVC010
TEMPO 2704/2707 2000 FEW002 SCT005 OVC010
RMK
T 22 23 23 24 Q 1011 1012 1009 1007

YAFT is outside controlled airspace and the use of Helicopter VMC is permitted at the aerodrome. An alternate aerodrome, with a TAF indicating CAVOK conditions all day, is located 35 minutes flying time away.

Assuming cruise fuel flow and holding fuel flow are similar rates, for a planned arrival time at YAFT of 270335Z the minimum additional alternate or holding fuel required is -

A 25 minutes holding fuel
B 35 minutes fuel to the alternate
C 30 minutes holding fuel
D 60 minutes holding fuel

The answer supplied was B. I selected D. This one might more sense if you say because you can carry fuel to your alternate you don't require the 60min holding fuel.

Hi Pierre,
This is a common 'gotcha!' in the CASA exams when it comes to Holding fuel required type questions.
You have read the fine print in AIP ENR 1.1 para 58.2.8 which states that if you arrive in the 30min buffer after forecast cessation, you only have to carry enough holding fuel to get you to the end of said buffer.
It's a sneeky one I know but when you start getting into things that burn fuel by the ton it can save carrying a lot of extra fuel unnecessarily. I know the old saying "only time you have too much fuel is when you are on fire!". The CASA exam is testing your knowledge of what is 'legally required'. We are talking CPL theory here which means that calculating minimum fuel required are some commercial considerations of running such flights.

However. If you arrive within the 30 minute buffer before the forecast commencement, like in your question 2, you're stuck with having to carry the lot.

I find that you have to read AIP ENR 1.1 para 58.2.8 a couple of times to really get to know it.

Hope this helps.

Cheers,

Mister W.

Thanks! Much appreciated. That does clear up most of it for me.

Now that I understand the meaning of paragraph 58.2.8 it makes more sense when reading it... go figure!