G'day,
After a bit of clarification on when to reduce the DA or MDA minima. In AIP ENR 1.5-36 5.3.2 it reads you may take 100ft off whenever actual aerodrome QNH exists, however is it always assumed the pilot uses it when available? In some questions it is specified the actual QNH is used, and in others it is assumed due to the fact the pilot has a clearance to land. So if the question doesn't specify the actual QNH is used, but its available via AWIS, do you assume the pilot has used it?
Does this apply to take-off minima that use the chart as well?
Thanks
Hi ejem,
Naturally a pilot will use the actual QNH, be it from ATC, ATIS or AWIS, because with a lower minima there is greater chance of landing. If the only QNH information available comes from the AWIS, that is what is used with the proviso from AIP 1.5-36 5.3.2 of -
"actual aerodrome QNH from an approved source is valid for a period of 15 minutes from time of receipt"
As for take-off minima? There is no mention of take-off minima in that section of the AIP. As you are there at the aerodrome you will have the actual QNH as you set your altimeter as you set field elevation.
Cheers W
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As a matter of interest, Jeppesen charts list the minima with actual or forecast QNH.
