Flying into areas of very low pressure
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Flying into areas of very low pressure
Looks like tomorrow's depression will drop below 949mb at the centre. I'll be flying into that area and our altimeter sub scales only go down to 951mb. Can't find anything in our company ops manuals regarding this issue. Has anyone experienced this situation? If so, how did you deal with it?
Thanks
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Hi,
This situation requires the use of QNE. This is the procedure where by the pilot sets 1013 on the altimeter and the controller gives you descents based upon that. So if you on a vfr approach for example, they will say "your altimeter will read x feet on touchdown."
I've never had to use it myself nor do I believe it's something written down in my own company ops manual but it's something I remember from training. Be interested to hear whether any controllers do this or have other methods in place ?
This situation requires the use of QNE. This is the procedure where by the pilot sets 1013 on the altimeter and the controller gives you descents based upon that. So if you on a vfr approach for example, they will say "your altimeter will read x feet on touchdown."
I've never had to use it myself nor do I believe it's something written down in my own company ops manual but it's something I remember from training. Be interested to hear whether any controllers do this or have other methods in place ?
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Fortunately, when the pressure gets that low the winds stop you flying.....
If you don't have RVSM, you can't fly in RVSM airspace, If you don't have RNAV, you can't fly in that airspace. If your altimeter doesn't go low enough, I'd stay on the ground.....
If you don't have RVSM, you can't fly in RVSM airspace, If you don't have RNAV, you can't fly in that airspace. If your altimeter doesn't go low enough, I'd stay on the ground.....
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Thanks for the replies. For us the QNH dropped to 956 at its lowest so everything was normal (apart for some pretty sporty landings! Into NCL) but at one point I checked Inverness QNH and it had dropped to 948 I think. Funnily enough the wind was also light and variable, so it must have been near the centre of the low.
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It's been glorious weather up here in Inverness this past week or so! Must have missed the worst of it.
Regarding the other post, you are well within your rights to fly into or out of an airfield when the pressure is less than or more than what a standard sub scale on an altimeter goes to. Admittedly it won't happen often but there are definitely procedures in place for this. The RVSM thing etc are totally different issues.
Jim.
Regarding the other post, you are well within your rights to fly into or out of an airfield when the pressure is less than or more than what a standard sub scale on an altimeter goes to. Admittedly it won't happen often but there are definitely procedures in place for this. The RVSM thing etc are totally different issues.
Jim.
