QNH???

my instructor told me not to worry about what "qnh" actually
means......... can someone here enlighten me please? i know it has
something to do with the barometric pressure and setting alt meter,
but what does QNH stand for...... as always thanks for your patience
guys and gals.....Im new here

Marlbra wrote:
my instructor told me not to worry about what "qnh" actually
means......... can someone here enlighten me please? i know it has
something to do with the barometric pressure and setting alt meter,
but what does QNH stand for...... as always thanks for your patience
guys and gals.....Im new here

QNH is the pressure that the air would be at sea level, if it wasn't for
the land all being above sea level. If you were to bore a hole down to
sea level, and lower a barometer down the hole to the bottom, then QNH
is what pressure the barometer would read. Theoretically.

If you set your altimeter to QNH, then it will accurately show you
altitude above sea level, so you can avoid busting into someone's
controlled airspace. It will also show the airfield elevation when
you're on the ground at the airfield.

Frank

On Tue, 22 Feb 2005 21:44:01 +1300, Frank van der Hulst
wrote:

thanks for that frank, instructor basically told me WHAT QNH actually
was, I was just curious as to what the letters stand for

Cheers

Marlbra wrote:
my instructor told me not to worry about what "qnh" actually
means......... can someone here enlighten me please? i know it has
something to do with the barometric pressure and setting alt meter,
but what does QNH stand for...... as always thanks for your patience
guys and gals.....Im new here

QNH is the pressure that the air would be at sea level, if it wasn't for
the land all being above sea level. If you were to bore a hole down to
sea level, and lower a barometer down the hole to the bottom, then QNH
is what pressure the barometer would read. Theoretically.

If you set your altimeter to QNH, then it will accurately show you
altitude above sea level, so you can avoid busting into someone's
controlled airspace. It will also show the airfield elevation when
you're on the ground at the airfield.

Frank

In article ,
Marlbra wrote:
my instructor told me not to worry about what "qnh" actually
means......... can someone here enlighten me please? i know it has
something to do with the barometric pressure and setting alt meter,
but what does QNH stand for...... as always thanks for your patience
guys and gals.....Im new here

It means do it "Quietly, No Hu-hu".


Well, you *asked* grin


Seriously, it is just a "code". an *arbitrary* symbol to which a particular
meaning has been assigned.

"Q" codes date from the days of Morse-code communications, where there was
a definite performance advantage to be gained by having "short-cut' symbols
for many "common" messages/phrases. example: it is *much* faster to
send the 3 Morse-symbols for "QRU" than it is to transmit "I have no traffic
for your station".

again........ brilliant, consise... my thanks

On Tue, 22 Feb 2005 12:41:55 -0000,
(Robert Bonomi) wrote:

In article ,
Marlbra wrote:
my instructor told me not to worry about what "qnh" actually
means......... can someone here enlighten me please? i know it has
something to do with the barometric pressure and setting alt meter,
but what does QNH stand for...... as always thanks for your patience
guys and gals.....Im new here

It means do it "Quietly, No Hu-hu".


Well, you *asked* grin


Seriously, it is just a "code". an *arbitrary* symbol to which a particular
meaning has been assigned.

"Q" codes date from the days of Morse-code communications, where there was
a definite performance advantage to be gained by having "short-cut' symbols
for many "common" messages/phrases. example: it is *much* faster to
send the 3 Morse-symbols for "QRU" than it is to transmit "I have no traffic
for your station".

QNH, QFE, QFF, QNE
When an airport measures the local air pressure, then this pressure is
called QFE. An airplane which has set the altimeter to the QFE value will
read zero feet on the altimeter when it is on the ground at this airport.

The QFE can be transformed into QNH by calculations and/or tables or
diagrams. In fact what happens is that the measured QFE is being corrected
for non-standard temperature, non-standard-humidity etc.

The resulting value is called QFF. This QFF value is then corrected for
field elevation, that means that it is transformed into a pressure as it
would have been at mean sea level (MSL) under standard conditions QNE (29.92
inches or 1013.2 mb of mercury at 59 degrees fahrenheit or 15 degrees
centigrade).

The resulting value is a local pressure value which we call QNH. An
airplane which has set the altitude to QNH value will read the field
elevation on the altimeter when it is standing at this airport!

Samm
I fly because it releases my mind from the tyranny of petty things . . . -
Antoine de St-Exupéry


"Marlbra" wrote in message
...
my instructor told me not to worry about what "qnh" actually
means......... can someone here enlighten me please? i know it has
something to do with the barometric pressure and setting alt meter,
but what does QNH stand for...... as always thanks for your patience
guys and gals.....Im new here

Back when I worked at Boeing one of the test pilots told me that QFE and QNE
stood for Queen's Field Elevation (altimeter reference to the field so it
read zero on the runway) and Queen's Normal Elevation (altimeter referenced
to sea level). I don't know if this was just a memory aid, or if QFE and
QNE are actually acronyms for Queen's Field Elevation and Queen's Normal
Elevation.... anyone know?

Dean

In article ,
Dean Wilkinson wrote:
Back when I worked at Boeing one of the test pilots told me that QFE and QNE
stood for Queen's Field Elevation (altimeter reference to the field so it
read zero on the runway) and Queen's Normal Elevation (altimeter referenced
to sea level). I don't know if this was just a memory aid, or if QFE and
QNE are actually acronyms for Queen's Field Elevation and Queen's Normal
Elevation.... anyone know?

Yup. *NOT* true. 'Q codes' are just that _codes_. Not Acronyms.

Furthermore, "logic" shoots down both your 'memory aid' interpretations.
an "elevation" is a _distance_ measurement above a reference point, not
a 'pressure' reference. One can trust the "Queen's English" to use words
properly. grin

On top of that... manned flight was invented HERE in the US... not in that
dental-challenged, pompus, take credit for everything, dung-hole!


"Robert Bonomi" wrote in message
...
In article ,
Dean Wilkinson wrote:
Back when I worked at Boeing one of the test pilots told me that QFE and
QNE
stood for Queen's Field Elevation (altimeter reference to the field so it
read zero on the runway) and Queen's Normal Elevation (altimeter
referenced
to sea level). I don't know if this was just a memory aid, or if QFE and
QNE are actually acronyms for Queen's Field Elevation and Queen's Normal
Elevation.... anyone know?

Yup. *NOT* true. 'Q codes' are just that _codes_. Not Acronyms.

Furthermore, "logic" shoots down both your 'memory aid' interpretations.
an "elevation" is a _distance_ measurement above a reference point, not
a 'pressure' reference. One can trust the "Queen's English" to use words
properly. grin

Jughugs wrote:

On top of that... manned flight was invented HERE in the US... not in that
dental-challenged, pompus, take credit for everything, dung-hole!


Actually controlled heavier than air flight was, not manned flight. The
Montgolfier of brothers of France were making manned flights in hot air
balloons in the 1700s.

Dan, U.S. Air Force, retired