User Guide

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ADF (Automatic Direction Finder)
Although the Bendix-King one installed in
our airplanes is a very nice modern unit, the
ADF overall is actually a pretty archaic
piece of equipment, dating from the 1930s.
Also called a “radio compass,” the ADF
can point its needle at any low-frequency
station it can receive. In a sense, it’s exactly
the opposite of the VOR: while the VOR can
show you where you are, but not which way
you’re pointing, the ADF can show you which way you’re point-
ing, but not necessarily where you are. The ADF indicator has a
movable compass card, which can be set by the knob at the 7
o’clock position. If you set your actual heading at the top of the
dial, the head of the needle indicates the present bearing from you
to the station, while the tail of the needle shows the radial from
the station to you…but if you want it to read correctly, you’ll have
to reset it every time you change your heading.
None the less, it
has its uses. As you get
deeper into the arcana
of instrument flying,
you’ll find approaches
based on non-directional beacons (NDBs), and unless you have
an approach-qualified GPS receiver and an appropriately pub-
lished “GPS overlay” approach chart, you’ll need the ADF.
Moreover, should you ever lose the services of your directional
gyro (due perhaps to a vacuum failure, or one of the instrument
itself), the ADF can provide a heading reference that’s much more
stable in rough air than the “whiskey compass” up in the wind-
shield.
Last but far from least, among the stations that fall within the
tuning range of the ADF are regular AM broadcast outlets. Not
only does this provide a very simple way of navigating if your des-
tination is a town large enough to have a halfway powerful AM
station - you can also listen to it! Many ADFs in high-performance
airplanes gather dust except during the World Series playoffs or
the Superbowl.
good form to “squawk standby” when on the ground, supposedly
to prevent cluttering up controllers’ scopes around the airport; but
in the real world, their equipment automatically “disappears” any
targets moving at less than flying speed anyway, so you might as
well ignore it. “TST” tests all the functions of the equipment and
lights up all the segments and legends on the display.
“ON” is what you’d expect to be the normal mode, but
they’ve pulled a fast one on you here: since current regulations
require all aircraft to have not only the transponder but the alti-
tude reporting equipment as well, your normal operating mode
will be “ALT.” In this mode, the “raw altitude,” or flight level,
being reported to the ground stations will be displayed on the left
of the transponder.
Note that this will not necessarily correspond to your altime-
ter reading unless the local pressure is 29.92 in. Hg. and you’ve
set the altimeter accordingly; it could be a couple of hundred feet
off either way if the local altimeter setting is particularly high or
low. (ATC’s computers automatically take this into account). More
likely, the only time you might use the “ON” position is if your
altitude encoding system is way off, in which case the controller
will tell you to “stop altitude squawk.”
You might want to remember a couple of specific squawk
codes, too. The emergency code is 7700, one to punch in anytime
you’re in real trouble (for example, an engine failure or other
inflight emergency). Somewhat less frantic is 7600, the code to
use when you’ve lost radio communications but are otherwise
OK. If you can still receive but not transmit, controllers will often
transmit to you “blind,” asking you to acknowledge by pressing
your “ident” button.
Finally, and relatively unlikely considering that this is a sim-
ulator, 7500 is the international code indicating “I’ve been
hijacked, but don’t really want to talk about it right now because
someone is shoving the nasty end of an AK-47 into my ear.”
Flight Instruction
Flight Instruction