Unless you have an instrument qualification I would suggest a sensible interpretation of 'in sight of the surface' to be able to perform a safe forced landing whilst maintaining visual flight at all times, and not 'being able to see a blade of grass' as has been suggested.

I think the point was that technically it would be legal with one blade of grass, rather than a practical suggestion?

Just to repeat what I actually said;:)

“If you are below 3000 ft, clear of cloud and in sight of one blade of grass you are OK legally.”

Practicality depends on lots of factors, not just pilot qualifications.

Rod1

If you are;

You are illegal on a VFR flight.

Because the visibility is less than that required for VMC if all you can see is one blade of grass.

Regards,

DFC

Sorry DFC, but I've just looked at the link suggested by "Human Factors" and the diagram (and my previous understanding) only require you to be "In sight of the surface" and with an "Inflight visibilty" of 5km. Therefore you could legally be at 1500ft above broken cloud with the surface in sight, so long as your visiblity above the cloud is 5km or more. It also adds that below 140kt IAS this can be reduced to 1.5km, but my old training book suggests that this is only applicable to those with an IMC/IR rating. Above 3000ft the limits are more stringent.
As far as the safety aspects go, I would rather (and often have) be above scattered or even broken cloud, than be stuck in poor vis below it. Obviously it needs constant observation, and if the holes start closing up a quick descent whilst still safe to do so.

LFP,

OCAS, the 1.5km becomes 3km if you have a PPL without an IMCR/IR. 5km between three and ten thou.

Practically speaking, 6km is horrible never mind 3!

DFC,

Have a good look at;

http://www.caa.co.uk/docs/64/ATS_Classifications.pdf

Note, the visibility minima is horizontal not vertical, so you could be at 2999 ft, in sight of one blade of grass and have a horizontal vis of 50km. This is LEGAL, I make on comment on the practicalities. Remember the original question was about flying above some cloud, not a discussion on horizontal vis.

Rod1

Round here the haze layer usually seems to top out at around 4,000'.

So you can be at 4,100', in flight visibility of hundreds of miles in all horizontal directions, not a cloud in sight, you can see the ground directly beneath you ... but can you see that airfield three miles away that you're wanting to land at? - no chance!

but can you see that airfield three miles away that you're wanting to land at?

I'd say that's quite a normal problem anyway, which is why one has GPS :)

Many grass runways are barely visible when in the circuit, unless one knows exactly what to look for.

... in my experience, if you can see a blade of grass, you are probably flying at about 10' and are at the correct height for the flare;)

The first time I used GPS to locate an airfield, I flew right over it without seeing it. That was Sleap, where the approach is along the runway center line at 2000 ft, for a variation on an overhead join. Sticking to the magenta line kept it hidden under the nose all the way. :O

Funny....I did the exact same thing on my skills test using DR. :rolleyes:

Had to be said :ok:

Relevance of 140kts to VFR in class B,C,D & E airspace
 

I recently had reason to refresh my knowledge of VFR flight limitations and consulted the classic CAA chart already mentioned:

http://www.caa.co.uk/docs/64/ATS_Classifications.pdf

This has been around for years and years and I wonder if an ommission has been overlooked. Either I am being thick (quite probable) or there is a lack of clarity concerning what rules apply to aircraft below 3000ft at speeds of greater than 140kts

For classes F and G, if your speed is slower than this, then you can fly down to 1500m forward visibility (this referenced by the * and text below the chart), otherwise you must have 5km viz or more.

For classes B, C, D & E, if you speed is slower than 140kts you can fly down to 5km viz. What applies if your speed is greater than 140kts? This is not stated. Has this been missed off for years/am I the first to query it (unlikely)?

You could guess and say that it goes up to 8km, as is required for flight above FL100. If this were the case, why does it not apply to flight between 3000ft and FL100? Or, does the speed limitation in these airspace classes not affect the viz at all, and just mean that at speeds greater than 140kts at less than 3000ft, I still only need 5km viz, BUT I must now have 1500m horizontal separation and 1000ft vertical separation from cloud, rather than just being clear?

clearfinalsno1,

A vanilla PPL has a vis minima of 3km attached to it. A VFR minima of 1500m only applies if you have CPL, IMC or IR. See the ANO sections for licensing and the Rules of the Air for airspace/VFR constraints.

If more than 140kts, the vis stays at 5km but you are subject to 1.5km and 1000' away from cloud constraint.

Thanks Tony. I forgot about the 3km limitation for non IMC holders.

Other readers can see this and other PPL(A) licence priviledges in the CAA's LASORS (Licensing, Administration, Standardisation, Operating Requirements and Safety) 2007 guide, available online free here:

http://www.caa.co.uk/docs/33/LASORS_07.pdf

Goto the the Section A appendices, Appendix F, paragraph 2 c i.

Has to be said that cloud separation and the 140kt limit are completely unenforceable, and are meaningless in practice anyway.

The hardest to spot planes (gliders) disregard the cloud spacing requirements totally.

One has to remember this stuff for the exams.

Is the ATS categories link correct?

If I'm in Class G above solid cloud (and clear of it) surely I'm in VMC?? There's no requirement to be in site of the surface surely.

I wonder if it is the poor standard of instruction, which leads to so many pilots not understanding the VFR minima?

Rod1

Quite possibly - It could explain why so many PPL's blunder around in poor vis just below cloud, when they could (as I often do) climb above and enjoy far superior conditions. A further benefit (for me) is that this normally gives a much smoother ride, rather than the inevitable "bumps" lower down.