Barometer Setting in Europe question...

Here in the US, the barometer setting used is either the local setting when below 18,000'
MSL or 29.92 when at or above 18,000' MSL. This is according to FAR 91.81.

My question is on understanding how this works in Europe (and other airspaces
besides the US). My current hazy knowledge is that the 18000 feet may be different
either by country or some other boundary. Could someone familiar with this crossover
in Europe or elsewhere advise me on how it works?

Thanks in Advance!

is that in Europe

wrote:

My question is on understanding how this works in Europe (and other airspaces

It differs vastly from country to country. As airspace structure does, BTW.

Basically, there are three settings: QNE, QNH and QFE. Yes, those
Q-codes are used in radio communications (as well as in printed material).

QNE means 1013.2 (i.e. 29.92). You set it above a certain altitude,
which differs from county to country, or above the transition altitude
at controlled airports, in which case the transition altitude is
published. On some airports it stays the same all the time, on other
airports it varies.

Below this altitude, you set either QNH (altitude above MSL) or QFE
(altitude above airport level). Again, this varies from one place to
another.

Sounds confusing? You get used to it.

Stefan

Thanks Stefan.
That's the simplest explanation I have yet to hear.

Stefan wrote:
QNE means 1013.2 (i.e. 29.92). You set it above a certain altitude,
which differs from county to country, or above the transition altitude
at controlled airports, in which case the transition altitude is
published. On some airports it stays the same all the time, on other
airports it varies.

Below this altitude, you set either QNH (altitude above MSL) or QFE
(altitude above airport level). Again, this varies from one place to
another.

wrote in message
k.net...
Here in the US, the barometer setting used is either the local setting
when below 18,000'
MSL or 29.92 when at or above 18,000' MSL. This is according to FAR 91.81.

My question is on understanding how this works in Europe (and other
airspaces
besides the US).

Canada has a 'Standard Pressure Region', and an 'Altimeter Setting Region'.

The 'Standard Pressure Region' is all airspace over Canada at or above 18000
feet, and all low level airspace that is outside of the lateral limit of the
'altimeter setting region'. (The 'low level airspace that is outside of
the lateral limit of the altimeter setting region' is essentially the arctic
and high arctic.)

While operating in the 'Standard Pressure Region', the altimeter is set to
standard pressure, which is 20.92 In.Hg, or 1013.2 mbs. (Except that for
departures and arrivals the airport altimeter setting is used, when
available, or, for departures with no altimeter setting available, the
elevation of the given airport)

While operating in the low-level airspace in the Altimeter Setting Region,
the altimeter is set to the altimeter setting (if known) of the given
airport for departures and arrivals, and otherwise the nearest station, and
otherwise the station nearest to the route of flight.

"Ron McKinnon" wrote in
news:Q9J2e.858461$8l.285987@pd7tw1no:

While operating in the 'Standard Pressure Region', the altimeter is
set to standard pressure, which is 20.92 In.Hg, or 1013.2 mbs.

20.92? Are you inside the eye of a hurricane or something?

"Jackal24" wrote in message
...
"Ron McKinnon" wrote in
news:Q9J2e.858461$8l.285987@pd7tw1no:

While operating in the 'Standard Pressure Region', the altimeter is
set to standard pressure, which is 20.92 In.Hg, or 1013.2 mbs.

20.92? Are you inside the eye of a hurricane or something?

Oops! Typo.

In article , says...


Sounds confusing? You get used to it.


Good post, Stefan.
Sounds confusing? It IS confusing, even when you get used to it.
Having flown both systems, the European system is really a nuisance!
It is (at least theoretically) justified because in Europe, the "general"
18000' altitude would not be sufficient to provide terrain clearance in all
locations, as it is in the US. Therefore, rather than create a special
airspace for the 10 sq-mi area concerned, the entire continent is subjected to
arcane usage rules, with transition altitudes and levels (they are different
when climbing and descending) that vary from day to day, depending on the
barometric pressure, and are different according to whether or not one is in a
TMA or other terminal procedure controlled airspace.

Generally speaking, however, these transitions almost always occur at or below
5500', so it is common to hear aircraft - even VFR - reporting FL5500, for
example.

Fortunately, the use of QFE - once dear to VFR-only pilots - is going by the
wayside. Time was, pilots would set their altimiters to "0" before takeoff,
then "at some point" transition to the local altimeter setting. On VFR
approach, they would set their altimeter to the field elevation, so they could
execute their pattern with the same reference altitudes displayed on their
altimeter, regardless of the actual field elevation. Good idea, I suppose, but
in reality it only added "one more" reference setting to the already thick
soup. This practice appears to be disappearing with the institution of
pan-European flight crew training.

G Faris

wrote in message
k.net...
Here in the US, the barometer setting used is either the local setting
when below 18,000'
MSL or 29.92 when at or above 18,000' MSL. This is according to FAR 91.81.

My question is on understanding how this works in Europe (and other
airspaces
besides the US). My current hazy knowledge is that the 18000 feet may be
different
either by country or some other boundary. Could someone familiar with this
crossover
in Europe or elsewhere advise me on how it works?

That's just about it. Different states set different thresholds (called the
"transition altitude") that are similar in effect to the 18,000 ft. At and
below that altitude a "local setting" is used and the vertical coordinate is
referred to as "altitude". Above that level 1013.25 hPa (= 29.92 inHg) is
used and the vertical coordinate is referred to as "flight level".

In some cases, different areas within states have different transition
altitudes for ATC purposes. For example in the UK, the general transition
altitude is 3000 ft, but within the horizontal extent of the London TMA it
becomes 6000 ft.

Julian Scarfe

"Stefan" wrote in message
...
wrote:

QNE means 1013.2 (i.e. 29.92).

This is actually a misconception, though a very commonly held one. When QNE
was used in RT, it represented the *elevation* that would be measured on an
altimeter set to 1013.2 at a reference station (usually an airport). Thus a
sea level airport with QNH 1010 hPa would report a QNE of approx 90 ft.

Q-codes generally represented questions and answers. "What is the standard
atmospheric pressure?" is a question with a predictable answer. ;-)

QNE no longer appears on the ICAO list of abbreviations and codes, so I
guess the distinction is of academic interest only.

Julian Scarfe

Julian Scarfe wrote:

This is actually a misconception, though a very commonly held one. When QNE
was used in RT, it represented the *elevation* that would be measured on an

I suspect you'll find even more inaccuracies in my post if you really go
for it. (The omission to point out the difference between transition
altitude and transition level jumps to my mind.) I tried to keep it simple.

A good list of the exact definitions of all Q-codes is he
http://www.kloth.net/radio/qcodes.php

Of allthose codes, the ones I think a pilot should (must) know are
QNE, QNH, QFE (in Europe, at least)
QFU (you'll find that on french approach plates, for example)
QDR, QDM, QTE (not good if you're lost and then confuse QDR and QDM)

Stefan