Abnormally low pressure approaches

[justmaybe]

Given the weather of recent months affecting the UK and the associated low pressure settings, just curious how controllers deal with approaches where QNE is requested, particularly in terms of vectors to platform altitude for example. Is there something in MATS that give you quick conversion tables etc?

[Talkdownman]

Is there something in MATS that give you quick conversion tables etc?
Yes. CAP493 Manual of Air Traffic Services Part 1 Appendix A. (http://www.caa.co.uk/docs/33/CAP%20493%20MATS%20edition%205%20amend%202%20complete.pdf)

[justmaybe]

Tks TDM. I was interested in how vectoring would be achieved. So, if initial altitude was say 3000' would you descent a/c to that level but given as a FL
(if that makes sense!)

[Talkdownman]

Dunno. In 47 years air-trafficking and flying I've never had a QNH off the sub-scale. QFE, yes, but not QNH. (It might be that there have been some cases recently West coast of Scotland or Ireland when it was Variable Force 11 Locally 12...).

Say the QNH is just off the sub-scale at 949 hPa, and elevation is 618ft / 21 hPa, then QFE is way off the scale at 928 hPa. Using the tables QNE is 2412ft ie. FL24-ish on touchdown. 'Sea level' is 618ft lower ie. FL18-ish. 3000ft altitude is therefore FL48-ish.

Probably best to have two brains checking the calcs...and extra guy ropes on the tower…and a Weather Standby…and a couple of nappies...