Re: Altimeter settings: QNH versus QFE

[stephanevdv]

Just another point in this discussion: when I look at an approach map of
an airfield, the pattern altitude is expressed as a height above
ground. To me, this means the easiest way of complying is to fly QFE
when entering the pattern (no mathematics needed) - providing of course
you can get the necessary information.

If you want to fly QNH, pattern altitudes should be expressed AMSL.

By the way, here in Europe (except UK, of course) glider altimeters are
in meters, not feet, thereby conforming to ICAO annex 5 whose purpose
it is to standardize units of measurement to the ISU. As the approach
maps (and other aviation maps) usually are in feet, we already have to
make computations anyhow.

It's high time we got rid of feet, knots and nautical miles! Their only
real purpose in aviation seems to be to make it more difficult to get a
pilot's licence, as you have to adjust to a new set of units. (Yes, I
know there are certain countries where they like to use outdated unit
systems. I also know the classical arguments like "a nautical mile
equals a minute of latitude", but how often do you fly true north or
south?)


--
stephanevdv
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

[309]

All of the aruguing aside, can anybody out there tell me a little of
the history of QNH, QFE, and QNE (etc.), specifically, WHAT does the
"Q" stand for??? The "F"? The "N", the "H" or the "E"???

I can see reasons for using each and every setting, and I can see
reasons for NOT using each and every setting.

My opinion is that we should all learn to do the math (in both
directions), and I am not practicing what I've just preached (at least
when it comes to using QFE!).

Just wait until there's another mid-air, and suddenly all gliders are
required to be equipped with transponders, TCAS, ADS-B, radio
altimeters and "bitchin' betty's" to annoy pilots getting too close to
stall (or spin)...

Again, where did the "Q" come from???

-Pete
#309

[[email protected]]

Argg I specifically didn't want to go into this can of worms! (see the
original post). IFR approach plates (at least in the US, where QFE
isn't used) give all approach altitudes in QHN, hence the need for an
accurate and recent altimeter setting. VFR pattern altitudes are often
given AGL, but they are pretty consistent: 1000', 1500' for jets,
perhaps 800' for gliders, etc. It really doesn't require a calculator
in the cockpit to figure out what number to put behind the needle on
the altimeter to be at the right altitude in the pattern. And it is a
lot easier to figure out the proper pattern altitude than to go through
the hassle of getting the QFE setting - assuming the airfield you are
landing at is low enough. It's a moot point in the US - ask tower for
a QFE setting and all you will get is "huh, say again?".

I understand in Europe it is common to have two altimeters in power
planes so that one can be set to QFE. Makes sense for instrument/low
vis approaches (pre-radar altimeter), if the "system" is setup for it
(QFE available from tower, appropriate approach plates, proper training
etc). Is this a correct assumption?

As far as going metric in aviation, sorry but I absolutely disagree -
metric units just don't work as well in aviation as feet/knots/NM,
IMHO. Metric altimeters are an abomination! And since almost all the
big boys (general aviation, airlines and military) use feet/knots/NMs,
everybody should. There is nothing sacred about the meter, after all -
any arbitrary unit will do if it is used consistently and satisfies the
needs of the users. Not that I expect any agreement on this point from
my European friends!

And the nice thing about nautical miles is that it is extremely easy to
get a quick distance measurement off a sectional chart by using the
nearest latitude scale - regardless of heading. Especially when the
kilometer scale is buried under the folds of the chart (or is on the
piece that got torn off to make the chart small enought to use in an
LS6's cockpit!)

My pet peeve in the US is that we usually fly in feet/knots, but set
tasks and give XC speeds in statute miles/MPH, then use kilometers for
badge and OLC flights. Absurd!

Seriously, it's interesting that the responses to the original topic of
this thread have not included any real defenders of using QFE in
gliders, just some reasons (excuses?) why it is done. Cmon, let's hear
it from you guys who are teaching it to your students!

Cheers,

Kirk
66

[Stefan]

309 wrote:

> All of the aruguing aside, can anybody out there tell me a little of
> the history of QNH, QFE, and QNE (etc.), specifically, WHAT does the
> "Q" stand for??? The "F"? The "N", the "H" or the "E"???

Nothing. It's just a code, the Q-code, to be precise :-) Maybe the Q has
a story, I don't know, but the latter two letters definitely do not.
Think of it as a numbered set of commonly used phrases.

A complete list of all Q-codes is at http://www.htc.ch/de/der_Q_code.htm
(German only).

Stefan

[Andy]

I was introduced to the Q codes as an army cadet in the signals wing.
One of the wonderful ones that stuck in my memory all these years was
"Shall I point my searchlight at a cloud, occulting if necessary, in
order to pinpoint my position" All that in 3 letters! They were used
for morse code communications before RT was available.

Andy

[Bruce Hoult]

In article . com>,
"309" > wrote:

> All of the aruguing aside, can anybody out there tell me a little of
> the history of QNH, QFE, and QNE (etc.), specifically, WHAT does the
> "Q" stand for??? The "F"? The "N", the "H" or the "E"???

"Query". These are Morse radio operator's abbreviations for common
questions they might ask of or be asked by a ground station.

http://en.wikipedia.org/wiki/Q_code

QNH is I believe "Nautical Height" and QFE is "Field Elevation" though
these are more mnemonics than definitions. What is the difference
between height and elevation? If you know, please explain why QNE might
be "Nautical Elevation".. (some sources suggest the mnemonic "anywhere"
for NE)

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

[Graeme Cant]

stephanevdv wrote:
> Just another point in this discussion: when I look at an approach map of
> an airfield, the pattern altitude is expressed as a height above
> ground.
The only ones I knew did that were the old Aeradio ones published for BA
when they used QFE. Never seen a Jepp chart in QFE - but I guess
they're produced that way for some operators.

> If you want to fly QNH, pattern altitudes should be expressed AMSL.
They almost always are on the charts I've seen.

> By the way, here in Europe (except UK, of course) glider altimeters are
> in meters, not feet, thereby conforming to ICAO annex 5
True. But in non-conformity to the great bulk of aviation globally. A
classic example of the problems of one-nation one-vote in these matters.

BTW - Aren't your altimeters in metres, not meters?

> whose purpose
> it is to standardize units of measurement to the ISU
No. Its purpose is just to standardise measurements. Feet are
perfectly good units to standardise on.

> . As the approach
> maps (and other aviation maps) usually are in feet, we already have to
> make computations anyhow.
Well stop resisting. Learn to think in feet instead of metres.

> It's high time we got rid of feet, knots and nautical miles! Their only
> real purpose in aviation seems to be to make it more difficult to get a
> pilot's licence, as you have to adjust to a new set of units. (Yes, I
> know there are certain countries where they like to use outdated unit
> systems. I also know the classical arguments like "a nautical mile
> equals a minute of latitude", but how often do you fly true north or
> south?)

ICAO working document(23/9/04): "...a study...completed in 1997,
indicated that 97% of jet aircraft worldwide were non-SI equipped
aircraft. Moreover, a growing number of non-SI equipped aircraft were
being operated by airlines of the small number of States which use SI
units."

You'll be flying in feet, knots and nautical miles for quite a while.
Better relax and go with the flow. :)

GC

>
> --
> stephanevdv
> ------------------------------------------------------------------------
> Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
> - A website for Australian Pilots regardless of when, why, or what they fly -
>

[Graeme Cant]

309 wrote:

> All of the aruguing aside, can anybody out there tell me a little of
> the history of QNH, QFE, and QNE (etc.), specifically, WHAT does the
> "Q" stand for??? The "F"? The "N", the "H" or the "E"???

The three letter "Q" codes date back to W/T, radio operators and Morse
code. They were a shorthand way of requesting/passing information and I
don't recall any where the other letters have any significance.

The only others I remember still in use are QDM - ILS inbound track or
runway direction and QSL - followed by a number to indicate radio signal
strength or readability.

Others (especially radio hams) may remember a lot more.

GC

[[email protected]]

Todd,

I was referring to the part of my original post where I said: "And
please, no tangential discussion about using QFE for IMC approaches
- unless you have two altimeters in your glider..." since I had a
feeling it would crop up and divert attention from the issue at hand.

As far as the pseudo QFE - amazing what some people will do to avoid
doing a little thinking in the cockpit.

Great discussion by all involved - I guess I'll just have to bite the
bullet and become a CFIG so I can impose my will on others!

Kirk

[Jack]

stephanevdv wrote:

> I also know the classical arguments like "a nautical mile
> equals a minute of latitude", but how often do you fly true north or
> south?)

How often do you look at a map?


Jack

[Tony Verhulst]

> I also know the classical arguments like "a nautical mile
> equals a minute of latitude", but how often do you fly true north or
> south?)

Airplane pilots like to look at the length of a course line, compare it
to the minutes latitude and know exactly the distance without the use of
any other tools. I understand that there are other tools. I was raised
as a Dutch man and brought up with the metric system - and prefer it.
But, to me nautical miles make sense, YMMV.

On another topic, why have horizontal speed in km/h and vertical speed
in meters/sec? To me, this is odd. If the units were the same, you could
simply divide one into the other and get the L/D - again, YMMV.

Tony V.

[Bill Daniels]

"Tony Verhulst" > wrote in message
...
> > I also know the classical arguments like "a nautical mile
> > equals a minute of latitude", but how often do you fly true north or
> > south?)
>
> Airplane pilots like to look at the length of a course line, compare it
> to the minutes latitude and know exactly the distance without the use of
> any other tools. I understand that there are other tools. I was raised
> as a Dutch man and brought up with the metric system - and prefer it.
> But, to me nautical miles make sense, YMMV.
>
> On another topic, why have horizontal speed in km/h and vertical speed
> in meters/sec? To me, this is odd. If the units were the same, you could
> simply divide one into the other and get the L/D - again, YMMV.
>
> Tony V.

Knots, MPH, KPH, meters/sec are just numbers. Just read the POH and fly the
numbers.

However, I have a beef with metric altimeters. The large hand reads 1000
meters per rev. An imperial units altimeter reads 1000 feet per rev. 1000
meters = 3281 feet so the metric altimeter is less than 1/3 as sensitive as
the one based on feet. To me, that seems inadequate.

I like to see the altimeter hand move with small changes in altitude.
That's confirmation that all is well in the instrument panel. I've seen
haywire varios insistently reading up while the altimeter was winding down.
I'm not sure I would have spotted that as quickly with a metric altimeter.

I suppose there is no reason that a metric altimeter could not be more
sensitive. With today's digital technology, 100 meters per rev should be
possible. I've never seen one that sensitive.

Bill Daniels

[Eric Greenwell]

Bill Daniels wrote:

> I like to see the altimeter hand move with small changes in altitude.
> That's confirmation that all is well in the instrument panel. I've seen
> haywire varios insistently reading up while the altimeter was winding down.
> I'm not sure I would have spotted that as quickly with a metric altimeter.
>
> I suppose there is no reason that a metric altimeter could not be more
> sensitive. With today's digital technology, 100 meters per rev should be
> possible. I've never seen one that sensitive.

Actually, even yesterday's digital technology already provides very
sensitive altimeters in our varios, GPS units, or flight computers.
These are digital readouts, of course, not hands, but I find myself
looking at my Cambridge 302 altimeter reading much more than the
mechanical one. You can use it in feet or meters, and have plenty of
sensitivity.

The next mechanical altimeter I buy will likely be an INsensitive unit,
like one of the 0-10,000' or 0-20,000 single hand units for less than $150.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Bruce Hoult]

In article >,
"Bill Daniels" > wrote:

> However, I have a beef with metric altimeters. The large hand reads 1000
> meters per rev. An imperial units altimeter reads 1000 feet per rev. 1000
> meters = 3281 feet so the metric altimeter is less than 1/3 as sensitive as
> the one based on feet. To me, that seems inadequate.

Some gliders I have flown have altimeters marked in feet, but 3000 ft
per revolution rather than 1000.

Presumably it's possible to design a single unit for either metric or
imperial use and tweak the calibration by the 10% difference.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

[GeorgeB]

On Fri, 03 Jun 2005 03:43:36 +1000, Graeme Cant >
wrote:

>309 wrote:
>
>> All of the aruguing aside, can anybody out there tell me a little of
>> the history of QNH, QFE, and QNE (etc.), specifically, WHAT does the
>> "Q" stand for??? The "F"? The "N", the "H" or the "E"???
>
>The three letter "Q" codes date back to W/T, radio operators and Morse
>code. They were a shorthand way of requesting/passing information and I
>don't recall any where the other letters have any significance.

I don't know, but wonder with the thought in creating Morse (most
common letters easiest to send), if the letters for the most common
(at the time?) were the least confusing and/or shortest sent in
combination?

[stephanevdv]

Funny to get exactly the reactions one could foresee. OK, I admit I
don't have much hope of getting the ISU units accepted in aviation, but
the "nautical mile/minute of latitude" story has been dealt with long
ago, shortly after the French Revolution. There still are French (I'm
Belgian, please don't mix us up) survey maps with longitude and
latitude in grades, not degrees (400 grades = 360 degrees). You then
have: 1 hundredth of a grade = 1 kilometre (UK) / kilometer (USA). Just
as efficient (or inefficient), and decimal, but it hasn’t been able to
replace the 360 degree system, not even in the ISU. Oh, by the way,
this geodetic system uses the Paris meridian as zero, not the Greenwich
one.
> why have horizontal speed in km/h and vertical speed in meters/sec? To
> me, this is odd. If the units were the same, you could simply divide
> one into the other and get the L/D
Odd, yes, but I’m not really in favour of calculating the L/D by
dividing indicated speed by sink anyhow: the value will vary wildly in
a relatively short time, and wind can play havoc with this kind of
calculation.


--
stephanevdv
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

[Stefan]

stephanevdv wrote:

> Just
> as efficient (or inefficient), and decimal, but it hasn’t been able to
> replace the 360 degree system,

Just to add confusion to the discussion: The decimal system has been
about the dumbest idea which has happened to mankind. The phoenicians
got it right by using the duodecimal system (actually, they used even
the 60-system), which is much more suited for most real life situations.
But some dimmer folks replaced it by the decimal system, because they
couldn't do the math without using their fingers. So I fear we have to
live with that.

Stefan

[stephanevdv]

And what about computer folks?
They can't go further than 0 and 1!


--
stephanevdv
------------------------------------------------------------------------
Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
- A website for Australian Pilots regardless of when, why, or what they fly -

[01-- Zero One]

'duodecimal system' -- We use that all the time in libraries in the
USA.

Larry

"Stefan" > wrote in message
:

> stephanevdv wrote:
>
> > Just
> > as efficient (or inefficient), and decimal, but it hasn't been able to
> > replace the 360 degree system,
>
> Just to add confusion to the discussion: The decimal system has been
> about the dumbest idea which has happened to mankind. The phoenicians
> got it right by using the duodecimal system (actually, they used even
> the 60-system), which is much more suited for most real life situations.
> But some dimmer folks replaced it by the decimal system, because they
> couldn't do the math without using their fingers. So I fear we have to
> live with that.
>
> Stefan

[Paul Lynch]

Get rid of feet, knots and NM???

That may work for gliders, but not necessarily for other type aircraft. The
math is simple using the nautical system with lots of shortcuts to do the
math simply. Mach number means nothing to glider pilots (save the shuttle
dudes), but it does to us jet jocks.


"stephanevdv" > wrote in
message ...
>
> Just another point in this discussion: when I look at an approach map of
> an airfield, the pattern altitude is expressed as a height above
> ground. To me, this means the easiest way of complying is to fly QFE
> when entering the pattern (no mathematics needed) - providing of course
> you can get the necessary information.
>
> If you want to fly QNH, pattern altitudes should be expressed AMSL.
>
> By the way, here in Europe (except UK, of course) glider altimeters are
> in meters, not feet, thereby conforming to ICAO annex 5 whose purpose
> it is to standardize units of measurement to the ISU. As the approach
> maps (and other aviation maps) usually are in feet, we already have to
> make computations anyhow.
>
> It's high time we got rid of feet, knots and nautical miles! Their only
> real purpose in aviation seems to be to make it more difficult to get a
> pilot's licence, as you have to adjust to a new set of units. (Yes, I
> know there are certain countries where they like to use outdated unit
> systems. I also know the classical arguments like "a nautical mile
> equals a minute of latitude", but how often do you fly true north or
> south?)
>
>
> --
> stephanevdv
> ------------------------------------------------------------------------
> Posted via OziPilots Online [ http://www.OziPilotsOnline.com.au ]
> - A website for Australian Pilots regardless of when, why, or what they
> fly -
>

[Tony Verhulst]

01-- Zero One wrote:
> 'duodecimal system' -- We use that all the time in libraries in the USA.

Groan :-).

Tony V.

[F.L. Whiteley]

Stefan wrote:

> 309 wrote:
>
>> All of the aruguing aside, can anybody out there tell me a little of
>> the history of QNH, QFE, and QNE (etc.), specifically, WHAT does the
>> "Q" stand for??? The "F"? The "N", the "H" or the "E"???
>
> Nothing. It's just a code, the Q-code, to be precise :-) Maybe the Q has
> a story, I don't know, but the latter two letters definitely do not.
> Think of it as a numbered set of commonly used phrases.
>
> A complete list of all Q-codes is at http://www.htc.ch/de/der_Q_code.htm
> (German only).
>
> Stefan

Don't forget the Z codes.

http://groups.msn.com/ctoseadogs/34z34signals.msnw

Frank

[Robin Birch]

In message >, F.L. Whiteley
> writes
>Stefan wrote:
>
>> 309 wrote:
>>
>>> All of the aruguing aside, can anybody out there tell me a little of
>>> the history of QNH, QFE, and QNE (etc.), specifically, WHAT does the
>>> "Q" stand for??? The "F"? The "N", the "H" or the "E"???
>>
>> Nothing. It's just a code, the Q-code, to be precise :-) Maybe the Q has
>> a story, I don't know, but the latter two letters definitely do not.
>> Think of it as a numbered set of commonly used phrases.
>>
>> A complete list of all Q-codes is at http://www.htc.ch/de/der_Q_code.htm
>> (German only).
>>
>> Stefan
>
>Don't forget the Z codes.
>
>http://groups.msn.com/ctoseadogs/34z34signals.msnw
>
>Frank
They are all simple codes originally sent by morse. If you look at the
whole list there are loads of things to do with radio comms as well as
the various things to do with aerial navigation.

They are widely used in amateur radio as well as in flying.

Robin
--
Robin Birch

[F.L. Whiteley]

Robin Birch wrote:

> In message >, F.L. Whiteley
> > writes
>>Stefan wrote:
>>
>>> 309 wrote:
>>>
>>>> All of the aruguing aside, can anybody out there tell me a little of
>>>> the history of QNH, QFE, and QNE (etc.), specifically, WHAT does the
>>>> "Q" stand for??? The "F"? The "N", the "H" or the "E"???
>>>
>>> Nothing. It's just a code, the Q-code, to be precise :-) Maybe the Q has
>>> a story, I don't know, but the latter two letters definitely do not.
>>> Think of it as a numbered set of commonly used phrases.
>>>
>>> A complete list of all Q-codes is at http://www.htc.ch/de/der_Q_code.htm
>>> (German only).
>>>
>>> Stefan
>>
>>Don't forget the Z codes.
>>
>>http://groups.msn.com/ctoseadogs/34z34signals.msnw
>>
>>Frank
> They are all simple codes originally sent by morse. If you look at the
> whole list there are loads of things to do with radio comms as well as
> the various things to do with aerial navigation.
>
> They are widely used in amateur radio as well as in flying.
>
> Robin
Quite right. One may send quite a complex message using a few Q & Z
signals, text, and numbers.

Frank

[Dave Martin]

For a complete list of Q codes in English see

http://www.zerobeat.net/qrp/qsignals.html












At 22:00 06 June 2005, F.L. Whiteley wrote:
>Robin Birch wrote:
>
>> In message , F.L. Whiteley
>> writes
>>>Stefan wrote:
>>>
>>>> 309 wrote:
>>>>
>>>>> All of the aruguing aside, can anybody out there tell
>>>>>me a little of
>>>>> the history of QNH, QFE, and QNE (etc.), specifically,
>>>>>WHAT does the
>>>>> 'Q' stand for??? The 'F'? The 'N', the 'H' or the
>>>>>'E'???
>>>>
>>>> Nothing. It's just a code, the Q-code, to be precise
>>>>:-) Maybe the Q has
>>>> a story, I don't know, but the latter two letters
>>>>definitely do not.
>>>> Think of it as a numbered set of commonly used phrases.
>>>>
>>>> A complete list of all Q-codes is at http://www.htc.ch/de/der_Q_c
>>>>>ode.htm
>>>> (German only).
>>>>
>>>> Stefan
>>>
>>>Don't forget the Z codes.
>>>
>>>http://groups.msn.com/ctoseadogs/34z34signals.msnw
>>>
>>>Frank
>> They are all simple codes originally sent by morse.
>> If you look at the
>> whole list there are loads of things to do with radio
>>comms as well as
>> the various things to do with aerial navigation.
>>
>> They are widely used in amateur radio as well as in
>>flying.
>>
>> Robin
>Quite right. One may send quite a complex message
>using a few Q & Z
>signals, text, and numbers.
>
>Frank
>

[309]

Thanks to all who've helped me understand the orign of the letters in
QNH, QFE, QNE, QUH, WTF...etc...

One of my aerospace co-workers (and a fellow Flight Test Engineer) was
musing aloud one day: "We all know what it MEANS, but what do the
letters STAND for??? Where did they come from?" As if QNH stood for
"Quintesstial Normalized Height," and QFE stood for "Quiet Field
Elevation," or ???

I tried to warn him that it was foolish to try and make sense out of
any three letters...take "FAA," for example... ;-)

Regards,

-Pete
#309

Dave Martin wrote:
> For a complete list of Q codes in English see
>
> http://www.zerobeat.net/qrp/qsignals.html
>

> >