Hi all

Say we are planning a IFR flight to a remote airstrip with no aid and using the no bkn cloud below the last route segment LSALT + 500 and 8k vis rule and the GAF indicates for example area "A" >10k vis and cloud well above the LSALT we are all good.
But then in area "A" it then goes on to talk about further down 2000m ISOL SHRA in the vis@WX section and BRK 600/2000FT which will be below our lowest safe.
Does this immediately mean that our flight will then require an alternate even though it says that the areas affected are isolated?.
And if it does not require a alternate at what level does it eg; ISOL, OCNL or FREQ

Regards

If your destination aerodrome is in that sub-area, then that sub-area's weather applies. If that is below the alternate minimum. you require an alternate.

Good question "Driver" !

Would and alternate be required for an IFR day flight into an aerodrome with no procedure using the following GAF? Assume that the LSALT over the final route segment is 3000'.

well Carello I reckon by what bob is saying then defiantly an alternate is required if LSALT is 3000

Thanks for the reply bob much appreciated. I had a couple of different answers from a couple of different people outside the forum

I can't see any option but to carry an alternate in this case. If the destination aerodrome is in Area B, and BKN cloud is forecast with a base of 1500ft AMSL along with visibility down to 4000m throughout the validity period of the forecast. The visibility is 10km or better except for the BKN cloud or smoke. But the BKN cloud and smoke are not location specific, so you would have to assume that those conditions are forecast to occur throughout Area B.

Well here is the problem - there is no sub-area like "B1" or "B2".

Secondly, we don't know if our flight will be affect by 5000M SCT RA or the 4000M ISOL FU on the final route segment at the planning phase.

In summary, it would be appear to be overly restrictive to plan an alternate if 7000M ISOL SHRA appeared on a GAF that was otherwise fine and beaut

Sorry Bob - your post came in just before I sent my last post.

I would have to agree - we would have to plan for the worst case.

thanks bob and Carello
Yes I agree the top line may look real good
but it will not need much extra to need an alternate

regards steve

Thanks for all the well written text books bob over a period of time I have used your books for all my commercial exams,PIFR and IREX all self studied at home with passes in all the first time