Originally Posted by
exfocx
No, I think you're wrong. My employer ops aircraft >5700 into non IAP no TAF airports, and has been doing so using GAFs (as do many others) and CASA is well aware of the operations and it isn't done off the back of a dispensation. With regards to NOT AVAILABLE I suggest the following conversation:
You (to a mate): Can I borrow your car today?
Mate: No, it's not available!
You: Well, can I borrow it tomorrow?
Mate: Nah, not available tomorrow either.
You: When will it be available?
Mate: Never.
You: WTF, why?
Mate: Because I don't have a car!
Wouldn't happen like that, would it? More like this:
You: Can I borrow your car?
Mate: Sorry, don't have a car!
You see, to be "not available", it has to be there in the first place. BoM may not be able to produce a TAF due to industrial action or maybe due to insufficient met data, or only enough data to produce a provisional TAF.
I would say in your argument, the TAF for ROSSOW with those conditions would be reflected in the GAF! However, I agree with you, going with it just on the margins like that wouldn't be smart, but having been using GAFs for those ops for 6 yrs I've yet to see that, or the GAF is split and your ROSSOW is other the dividing line with the ****ty WX. Now that I have seen and have taken appropriate precautions fuel wise.
Yes totally agree.
If the weather was this bad on the TAf, i struggle to see how this wouldnt be somwhat close to being reflected on the GAF. The GAF is generally much more conservative and whilst im sure there is the odd occurance where the GAF is not reflective of the TAF, in my experience, most GAFs paint the same if not much worse picture that what a TAF would, irrespective of even being able to permit flight at LSALT+5 ( the alternate minima to a negative TAF destinaition).
Lets not forget the opening post to this thread was about a CAVOK clear day.
The law supports the fact and permits no TAF in the fact that one requires a GAF to a non IAP destination ( ENR 1.10) and this will show ( 90% of the time) a sufficent coverage of the potential weather, and at worst it will prevent you from not carrying alternate with the LSALT+5 requirement ( which automatically requires the cloud base to be at 2000ft minimum since min LSALT is 1500ft from memory). Now, im sure that if an AD was forecasting BKN at 800ft, the GAF would at least show signficant cloud below LSALT+5.
But dont get me wrong, if the weather was marginal, nearby AD TAF's paint a bad picture and knowledge of wider area weather suggests being able to conduct a VA by day or establish VMC within 3 by night at a non IAP destination could be marginal, an alternate will be strongly considered !