Hello everyone,

I'm looking for some clarification/advice on the VMC rules; AIP ENR 1.2-4 in particular. I was sure that I was interpreting these right but someone I trust on these matters has a different interpretation.

The situation: we're at YCRL (Crookwell, roughly 3000ft elevation) in a PA28 or C172 (exact type doesn't matter, the important thing is that it's an aeroplane rather than a helicopter or balloon). Cloud is overcast at 4000ft AMSL (ie 1000ft AGL). The pilot is VFR-only. Can we go flying?

My understanding of the VMC specifications was that you'd be fine in this case. If you stay at or below 1000ft AGL you just have to remain clear of the cloud. The 3000ft AMSL limitation for VMC is irrelevant because you have to be either at/below 3000ft AMSL or at/below 1000ft AGL. This isn't a populated area (the airfield is well clear of the town) so you could do circuits at a bit under 1000ft AGL without causing any problems.

The alternative interpretation of the rule (I may need to clarify this with the other party) seems to be that you must be below 3000ft AMSL and below 1000ft AGL. This would allow you to get out of very low-lying airfields like Bankstown or Moruya in low cloud, following the terrain up (remaining at 1000ft AGL) - but would not get you out of Crookwell (because you'll be over 3000ft AMSL the minute you leave the ground).

Any advice would be very much appreciated!

Cheers,
Evan Slatyer

Your interpretation is correct. To take advantage of the 'clear of cloud' rule, you must be below 3000ft AMSL OR 1000ft AGL. The AIP makes that clear when it says -

"At or below whichever is the higher
(a) 3000ft AMSL
(b) 1000ft AGL".

Remember also the the other requirement is that you have VHF radio and are monitoring the appropriate frequency.

Excellent, thank you very much for the reply and clarification - and for the reminder about the radio.

I'm pretty religious in keeping to the correct frequency around "known" aerodromes but it's a bit confusing at places like Braidwood (has an aerodrome marked on the map, but the airfield hasn't existed for quite a few years). The correct course of action appears to be to treat it as if there's a fully-operational non-controlled aerodrome there, make appropriate inbound broadcasts on Multicom at or before 10nm, and remain on Multicom until well clear of the area. However, since there isn't actually an airfield there, it feels like it would probably be safer to stay on Melbourne Centre throughout - where I can get traffic warnings, weather updates, etc.

Do you have any advice on that situation?