Eh What !! I nip under my rock for a couple of days and look what happens.
Timothy, I do not want to get into legalities on this issue but for those not wishing to thumb through the books this is what the Rules of the Air has to say.
Flight outside controlled airspace
Rule 26
(1) An aircraft flying outside controlled airspace at or above flight level 100 shall remain at least 1500 metres horizontally and 1000 feet vertically away from cloud and in a flight visibility of at least 8 km.
(2)
(a) Subject to sub-paragraph (b), an aircraft flying outside controlled airspace below flight level 100 shall remain at least 1500 metres horizontally and 1000 feet vertically away from cloud and in a flight visibility of at least 5 km.
(b) Sub-paragraph (a) shall be deemed to be complied with if:
(i) the aircraft is flying at or below 3000 feet above mean sea level and remains clear of cloud and in sight of the surface and in a flight visibility of at least 5 km;
(ii) the aircraft, other than a helicopter, is flying at or below 3000 feet above mean sea level at a speed which according to its air speed indicator is 140 knots or less and remains clear of cloud and in sight of the surface and in flight visibility of at least 1500 metres; or
(iii) in the case of a helicopter the helicopter is flying at or below 3000 feet above mean sea level flying at a speed, which having regard to the visibility is reasonable, and remains clear of cloud and in sight of the surface.
Now in my thinking the lowest form of VFR outside CAS is in sub-para ii) which requires a flight vis of 1500 metres. So technically can you take off VFR in something less than that?
As other ATCOs have posted we are not policemen and I am not going to go into mega form filling on every occasion someone leaps off VFR in any sort of crud. I have been tempted to do so myself sometimes but the thought of what happens in a single engine aeroplane if it all go's quiet after lift off tends to keep me drinking coffee til things improve.
Things get more interesting when someone departs VFR in the murk and is then NOT on top of cloud. That is more commonplace around Biggin than the shallow fog scenario. Now I have launched someone VFR who is now IFR and I have certain added responsibilities as an ATCO, like ringing up AlanM and appologising for the pop-up IFR
