Hello

Question 1

Q46 on page 392 of the PPL book asks for time available for a VFR flight from HAY to AYERS ROCK. EOD and BOD are given in LMT for HAY and AYERS ROCK, respectively. Going to the ERSA, HAY is UTC + 10 and AYERS ROCK is UTC + 9.30. This means BOD HAY is 0615LMT = 2015 UTC -1 and EOD AYERS ROCK is 1715 LMT = 0745 UTC.

Therefore, daylight is 11 hours 30 mins (subtract BOD HAY from EOD AYERS ROCK). Now we want to land 30 minutes before EOD which means we have 11 hours available for flying.

At least, that was my calculation but the answer suggests 11 hours 25 mins is correct.

Question 2
I understand the questions in PPL exam prep module (the online questions) are the same as those in the PPL Study Guide. Is this understanding correct? The Aviation Theory Centre has been suggested for additional questions. Anything else that's recommended?

Appreciate any help. Thanks

G'day HPound,

In regards to your first question, as far as I can recall, you need to use the Arc to Time based on the longitude and latitude of the location you are dealing with. You can find the Arc to Time tables in the AIP or VFR Guide.

Ayers Rock is 25 11.2 South and 130 58.4 East. Therefore, Arc to time is 8 hours and 44 mins.

1715-0844 = 0831 UTC

HAY is 34 31.9 South and 144 49.8 East.
Therefore Arc to time is 9 hours and 39 minutes.

0615 - 0939 = 2036 UTC

Finally, subtract the times to find out how many hours of daylight you have.

2036 - 0831 = 11 hours and 55 mins.
Then subtract 30 mins as you said = 11 hours and 25 mins for flight

Hope that helps!

Hi Aaron. Thanks for the response. Following your method I get the right answer - I'm converting LMT into UTC by adjusting for arc to time.
HAY: 06.15LMT less 09.39 = 21.36 UTC -1
AYERS ROCK: 17.15 LMT less 08.44 = 08.31 UTC
Time b/w HAY in UTC and AYERS ROCK in UTC = 11:55
Subtract desire to arrive 30 mins before EOD means flying time available is 11:25 (this is the correct answer).

However, I'm not clear on why can't I used the ERSA to covert from LMT to UTC? If I know BOD/EOD in two different locations, and I know the difference b/w the LMT (of each location) and UTC (as provided in the ERA), can't I simply covert the LMT to UTC?

I know I can't (thanks to your explanation), I just don't know why!

Thanks

I just updated my previous post, but in regards to that question. The UTC+10 is only based on the time zone of that region where the airport is, not its true position on the Earth's surface. The UTC figure therefore will provide you with inaccurate answers, using Arc to Time will provide you with more accurate answers

Cheers

Crystal clear - thank you!