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Lew747
6th Oct 2012, 07:48
I'm studying met and whilst I was at my brush-up in Bristol we was told to basically memorise the hPa levels for certain flight levels.

I.e.

FL50= 850 hPa
FL10= 700 hPa
FL180= 500 hPa
FL300= 300 hPa

etc..

But surely there must be a way of calculating these rather than memorising them? Even approximately. Is there a formula out there somewhere?

It's not that I don't mind memorising them, but rather curious as to how they work the figures out.

Cheers :ok:

Marchisio
8th Oct 2012, 03:40
I think you can use the formula to calculate changes in altitude

H = 96 x T
________
P


T = absolut temperature at that level in degress kelvin
P = actual pressure in HPa
H = height changes per HPa per feet

michaeljpotter
9th Oct 2012, 01:35
I dont remember any questions asking me apart from 300hpa = FL300 on my met exam.
You will tend to find that in some questions they answer the question for you.
E.g Your flying at the 500hpa (FL180) level and you encounter...etc. Its unlikely you'll be asked any other than 300 or 500 hpa. Just memorise them.