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