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RPS and QNH mixed messages

This is pulled straight from https://airspacesafety.com/

Now I don’t know who behind this website or if there is any CAA involvement but it certainly seems strange as what they state goes against what is taught at PPL level and also what happens in day to day flying.

“Avoid flying on the RPS in the vicinity East Midlands CTAs or below the DTY CTA. When flying on the RPS, as it is the forecast lowest QNH for a region, you will be higher in relation to the East Midlands QNH. If you are receiving a FIS from London Flight Information Service, ask the FISO for the East Midlands QNH rather than remaining on the Barnsley RPS.”"

So my question is why do London Information pass you the Barnsley in the first place?

“Avoid flying on the RPS in the vicinity of Doncaster Sheffield CTAs. When flying on the RPS, as it is the forecast lowest QNH for a region, you will be higher in relation to the Doncaster Sheffield QNH. If you are receiving a FIS from London Flight Information Service, ask the FISO for the Doncaster Sheffield QNH rather than remaining on the Barnsley RPS”

Although I haven’t flown in this area for a few months the last time I did the local LARS provider passed me the Barnsley? Why is this then?

This image is also pulled of the same website

Which basically seems to confirm what everyone has been saying for years. But I’m getting a lot of mixed messages here every PPL book on navigation tells the student to select the RPS and every LARS provider that I call gives me the RPS. Yet I read this website which I assume is set up to reduce infringements and it goes against this?

Ialso find it worrying that as it would appear to be proven that RPS is a major cause of infringements why hasn’t nothing been done to address it?

Last Edited by Bathman at 08 Feb 10:31

Just avoid this. Never set RPS. Always use a QNH of an airport that is more or less nearby. Saves you from both hitting the ground or airspace above.

Frankfurt (EDFZ, EDFE), Germany

Doing a google on airspacesafety.com finds some interesting stuff (my emphasis in yellow )

WHOIS shows the owners to be totally redacted

Since the CAA publishes its CAS etc busts numbers on it here it is probably a NATS-CAA joint project.

Bosco is spot on – the RPS is complete nonsense and should never be used. You will just get busted. God only knows why the NATS-CAA lot are talking about RPS on the same website on which they publish their infringement “pilot sentencing” data.

Administrator
Shoreham EGKA, United Kingdom

I set my own airport QNH (or nearby ATIS or London QNH) and give airspace limit/terrain msa good 300ft margin

I know what is RPS but I have no clues what “Wessex QNH” means (an got that few times from LARS in class G, sounds medieval to me ), it is usually close to the number I have in my box from nearby airports

ESSEX, United Kingdom

This is completely nuts.
How on earth is anybody who wasnt taught in the UK going to know any of this?
Common sense dictates that you talk to any FIS, and they SHOULD give you the correct QNH for where ever you are flying – you should never have to ask " is this what I need to set on my altimeter to avoid an infringement?".

skydriller spot on. What a ridiculously tangled set of rules, procedures and airspace design we have to try and fly in legally and safely. Only civil servants and ex-mil could design such a mess! (only jesting)

UK, United Kingdom

RPS was designed so that you are using the lowest forecast pressure for an area, in the absence of anything more accurate it is to ensure that you will not fly into the ground because you should be slightly higher than if you had an accurate pressure set. Ideal for Shackletons flying low level over the sea.

Because RPS will invariably mean the aircraft is higher than the altimeter might show, you must not use it anywhere where there is controlled airspace above you,because you are likely to infringe vertically. This is fundamental PPL teaching of Altimetry and anyone who was taught to fly on RPS without understanding this was badly taught.

As a pilot you are given the RPS incase you need it, the choice to use it is up to the pilot. The term Regional QNH is incorrect, a QNH is the pressure measured at a point and adjusted to give seal level pressure, you cannot have a point covering an area.

It is worrying that the CAA has to publish such a basic fact because some pilots do not understand a subject they were taught and examined in.

Tumbleweed wrote:

This is fundamental PPL teaching of Altimetry and anyone who was taught to fly on RPS without understanding this was badly taught.
It is worrying that the CAA has to publish such a basic fact because some pilots do not understand a subject they were taught and examined in.

The RPS in not mentioned in the TK syllabus, so I don’t agree that someone not knowing it was badly taught.

ESKC (Uppsala/Sundbro), Sweden

PPL syllabus is national, no? Only the UK uses RPS.

Administrator
Shoreham EGKA, United Kingdom

Peter wrote:

PPL syllabus is national, no? Only the UK uses RPS.

The detailed PPL syllabus is national, but the general PPL syllabus is in AMC1 to FCL.210. It mentions “The different barometric references (QNH, QFE and 1013.25)”. RPS is not mentioned.

The CPL has a detailed syllabus in AMC1 to FCL.310. It also doesn’t mention the RPS.

In any case, a PPL issued by an ICAO member state is valid in every other ICAO member state.

Last Edited by Airborne_Again at 10 Feb 09:25
ESKC (Uppsala/Sundbro), Sweden
24 Posts
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