87th VFW SOP Jan 2013 - Change 2

4.5 Altimeter setting
All 87 th pilots should use hecto pascal (hPa)
for their altimeter settings. Hence, make
sure you have unchecked the “Use Hg
Altimeter” (Figure 1).
Figure 1: The Falcon BMS Configuration
QNH is defined as, "barometric pressure
adjusted to mean sea level." It is a pressure
setting used by Air Traffic Control (ATC) to
refer to the barometric setting which, when
set on an aircraft's altimeter, will cause the
altimeter to read altitude above mean sea
level within a certain defined region. Such
pressure setting for the local airbase can be
obtained by calling the tower (ATC menu
page 2 - QNH) and can be set on the
altimeter using wheel on the mouse. The
transition altitude (TA) is the altitude
above sea level at which a/c change from
the use of altitude to the use of flight levels.
When operating at or below the TA,
altimeters are usually set to show the
altitude above mean sea level (QNH).
Above the TA, the aircraft altimeter
pressure setting is adjusted to the standard
pressure setting (SAS) which is QNE (29.92
in/Hg or 1013 hPa) and aircraft altitude
will be expressed as a flight level. While use
of a standardized pressure setting
facilitates separation of aircraft from each
other, it does not provide the aircraft's
actual height above ground. The transition
altitude in BMS is fixed at 14.000‘. Hence,
below 14.000’ we operate on local QNH
settings provided by tower, while above we
use QNE. The F-16 avionics are capable of
providing altitude based on the
measurement of atmospheric pressure
(BARO). The altitude shown in the HUD
will be information provided from the
barometric altimeter. Setting the altimeter
to (RADAR) will provide the pilot with
height above ground. The RADAR altimeter
is also a component of the terrain
avoidance warning systems, warning the
pilot if the aircraft is flying too low, or if
there is rising terrain ahead. When RADAR
is selected the altitude shown in the HUD
display will be fed from the radar altimeter.
The last option is (AUTO) and the altitude
shown in the HUD display will be fed from
the radar altimeter or the barometric
altimeter. If either jet altitude is at/below
1500’ AGL and the jet is ascending or if the
altitude is at/below 1200’ AGL and the jet
87 th Stray dogs | Standard Operating Procedures | 2013 | Change 2 Page 14