Flying into Cloud

[mm_flynn]

SF,

The issue of getting back down is equally true in all of the countries that do allow VFR flight above a cloud deck by plain PPLs. They admonish pilots to use good judgement and planning so you are sure it is a localised cloud deck an can get back down. This difference in rules doesn't seem to show up in a higher level of safety in the UK. I suspect the logic of SF and IO540 was used by the CAA drafters who came up with the rules.

[Tall_guy_in_a_152]

Can I extend this discussion with a related question based on circumstances I have found myself in a couple of times but IMC training did not prepare me for.

Say I am flying in VMC between two solid cloud layers (or cloud and CAS), but the vertical separation is only 1000ft. There is not a legal FL available within the 1000ft. This is all happening above the transition level.

My options appear to be:
1) Fly IFR in cloud above or below the VMC layer
2) VFR below cloud
3) VFR in the VMC layer, legally at any altitude I choose (subject to usual VFR rules).
4) stay at home

(3) appeals far more than (1),(2) or (4), but what altitude to pick? What I have done is pick a quadrantual level + or - 250ft and ideally putting me furthest from head-on traffic as possible. If VFR then I should be at an altitude rather than FL, but surely in this environment setting 1013 would be more sensible?

Supplementary question, if there are a few fluffy clouds in my (mostly) VMC layer, would it be best to just abandon any pretence of VMC and go IFR in IMC or would you "ride out" a few seconds in the clouds?

I appreciate that there probably are not right or wrong answers to the above, but opinions are welcome.

[dublinpilot]

Tall guy.....you've confused me with a couple of things you said....


If the vertical serperation between the cloud layers is only 1000ft, and you are above the transition level, then you are not meeting the requirement of VFR. You need to be seperated from cloud 1000ft vertically under VFR above 3000ft. To meet his you'd need a 2000ft gap between the cloud layers. So your option 3 doesn't seem to be legal. It may very well be the most sensible though

You also say

If VFR then I should be at an altitude rather than FL, but surely in this environment setting 1013 would be more sensible?

Why? There is no prohibition on using FL's instead of altitudes when under VFR, in fact it makes sense to use FL's as that's what everyone else will be using. Or did you mean something else?

dp

[bookworm]

If the vertical serperation between the cloud layers is only 1000ft, and you are above the transition level, then you are not meeting the requirement of VFR. You need to be seperated from cloud 1000ft vertically under VFR above 3000ft. To meet his you'd need a 2000ft gap between the cloud layers. So your option 3 doesn't seem to be legal. It may very well be the most sensible though

Indeed. Option 3 may not be technicaly legal, but the regulation is likely to be almost unenforcable (ever heard of a prosecution for breach of the quadrantal rule?) and it would seem to be the best option from the point of view of safety management. On most days, it's likely to put you at less risk of collision than VMC below cloud, and probably less than IFR in the cloud.

[Tall_guy_in_a_152]

Good points, DP. I had not considered 1000ft from cloud up and down.

I am under the impression (probably wrongly) that when VFR one flies quadrantal on QNH and IFR on 1013. I agree that for the purposes of collision avoidance that is a bit daft!

Thanks Bookworm, for the purpose of this discussion I am more interested in "sensible" rather than legal! Not that I would ever do anything illegal, of course.

[smith]

If flying VFR above the transition altitude I was under the impression it was advisable, but not mandatory to fly the quadrantial rule. ALso at low altitude eg 4,000ft, if you set 1013 and the QNH is vastly different you could be hundreds of feet out.

[IO540]

However, in Class G, few people bother about any of this.

There is a statistical argument for flying the quad or semi levels/altitudes but as far as I can tell it's rather tenuous.

Cloud spacing is unenforceable - even if you could actually estimate the distance with any accuracy.