Hi Bob and those on the Forum,

When asked to determine an accurate cloud ceiling height for an alternate, how is this done if you are asked a written question when a TAF states Few008 + SCT010. AIP ENR 1.1 58.2.1 page 87, says those two combined cloud amounts will equal BKN, but at what height.

Common sense would say the ceiling is at 1000' due to the layering of FEW + SCT and continue on to however high the cloud extends.

In the AIP wording, "Forecasts amount of cloud below the alternate are cumulative"; so if my alternate was (1200-2.4) and as above the layers of cloud are below my alternate minima, which when added together are >4/8ths cloud, the exact height is not an issue, but the height (AGL008 & AGL010) is below my alternate minima of (1200-2.4).

I may have answered my own question, just a bit confused.

Am I on the right track? Would appreciate another opinion

Cheers.

Yes, I think you have answered your own question. If both layers of cloud are below the alternate minimum then it is true to say the there is more than 4/8 of cloud below the alternate minimum. The actual distribution of cloud at 800 feet and cloud at 1000 feet is irrelevant. Good to see that you are a thinker!

Bob

Thanks Bob,

Good to have another opinion and that's what your forum is all about. This is a great learning tool you have provided. IREX in a week and I'm at that point where I've learnt so much I'm starting to doubt myself But I'm still coming up with the right answers. Again like some of the CPL subjects allot of this course has been developing an understanding of the expected language and the pathway back from the index to the answer; not so much about knowing the rule or action to take but more about the pathway in finding the information.

Cheers