Hi again everyone,

Have come across this question in the CASA sample Q's and need some clarification and assistance.

No TAF so you say an Alternate is required. However. If the Area Forecast says you have LSALT + 500 and 8km's then an alternate isn't required.
Mitchell YMIT is off the track by 90 miles- I must be missing something with this 90NM's- the clue?

Would you use the grid LSALT +500 etc or something else?

Thanks in advance again.

Heres the question:


ERC L4 refers.
You are planning a flight, by day, from CHARLEVILLE, QLD (YBCV) (S2625 E14616) to MITCHELL, QLD (YMIT), 90 nm to the east along W369. ETA is 0400 UTC. No TAF is available for YMIT, an unlicensed aerodrome. Area Forecast valid for your flight indicates the following conditions:
WIND: 2000 ft L/V 5000 ft 170/10 7000 ft 190/15
CLOUDS: BKN CUSC 4500/9000
VISIBILITY: 8 KM
Is an alternate aerodrome required, and why?

In addition to the above. What would one consider the "last Route Segment" for an airport off the route without an aid? Mitchell is 90NM off the route.

Thanks

Yes, you've got it. CASA do not update the sample questions, so many of them are out of date. After all they are only sample questions.

The 'no TAF' issue has been going on for some time, and there seems to be some confusion about it. You will note that the AIP says that the 'LSALT + 500 and 8k visibility rule' applies to an aerodrome without an instrument approach procedure - it doesn't mention anything about no TAF.




Also ENR 1.10 says a similar thing;




If you put on your lawyer's hat, it seems to be saying that, if the aerodrome has no TAF, you always need an alternate - even if it's 8/8 blue! You can only take advantage of the LSALT + 500 and 8k visibility rule if the aerodrome has no instrument approach procedure. No one in CASA seems to be able to help with that one. I can only assume that there wouldn't be any exam questions involving it.

Thanks, Bob for the info.

For the exam, I'll use the "lawyer hat"

Just out of interest. How would you interpret that question with regard to LSALT + 500 8km when an airport is off the route (i.e. 90NM)? Would grid LSALT be applicable or calculate own LSALT from obstacle reference on a chart to then calculate your minima for an alternate?

Thanks

Once again you need to put on your lawyer's hat. The AIP says "LSALT over the last route segment" - as far as I can see,that's not the same as grid lowest safe -although I'd certainly be happy to use it. If the route was not published on an ERC, you would need to establish a LSALT over the last route segment by applying the rules for calculating LSALT.

I don't know why we have these coversations. Surely it would be acceptable to use grid lowest safe - either they are safe or they are not. Never the less, in the wonderful world of theory, you can only go by what's written in the documents....

Thanks for your help, Bob- cap well and truly applied