BY ORDER OF THE SECRETARY OF THE AIR FORCE AIR FORCE ...

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AFMAN 11-217V1 3 JANUARY 2005
cumbersome when used to determine angular relationships with a desired course or
other traffic. Vertical velocity, an indispensable element in flying a precision glide
path using conventional pitch reference techniques, becomes extraneous data when
flying a glide path with a valid FPM. It is apparent then that proficiency in HUD
flying requires the development of an integrated crosscheck that encompasses the
most useful information available. Always confirm the HUD data before using it and
continue to crosscheck it against the head-down data to confirm its accuracy.
20.2.2.4. Navigation Information. Navigation information displayed on the HUD
varies from aircraft to aircraft both in symbology and format. Sources (INS,
TACAN, ILS) may be selectable, so it is important to remember which source has
been selected and whether the display is raw data or steering information. The ILS
mode may display either course guidance or course deviation. As in flying command
steering bars on an attitude indicator, the pilot must not fixate on HUD steering
commands but continue to reference raw data to determine aircraft position and to
verify the HUD commands. Chasing the steering commands with the FPM may
result in over-controlling, especially if raw data is not provided on the HUD.
20.2.2.5. Information Missing. The lack of power indicators and bearing information
prevents most current HUDs from providing complete “control” or “navigation”
information and reinforces the need for the pilot to use the HUD as only part of an
integrated crosscheck.
20.2.3. Instrument Flight Use. To effectively use the HUD for instrument flight, the
pilot must first understand basic attitude flying procedures and techniques and be
proficient in flying instruments using various elements of HUD information to
complement the instrument crosscheck.
20.2.3.1. Instrument Takeoff and Climb. Prior to takeoff, ensure that information
displayed on the HUD agrees with that on the conventional instruments. Rotation is
accomplished by establishing the initial pitch attitude using a combination of outside
visual cues and the attitude reference. The initial pitch attitude may be set on the
HUD if it contains a pitch reference symbol, otherwise, use the head down attitude
reference. When the FPM becomes active and a stabilized pitch is established, use
the FPM for precise adjustments. Continue to crosscheck the airspeed and VVI to
ensure the climb angle is correct, making adjustments using the FPM as necessary.
20.2.3.2. Level Off. Begin the level off at a predetermined lead point. Fly the FPM
smoothly to the level flight path line, adjusting the rate of movement so that level
flight occurs at the desired altitude. When the FPM is stabilized on the horizon line
of the HUD, the altimeter and VVI should be steady. The HUD information should
be considered unreliable if indications of a climb or dive persist.
20.2.3.3. Penetration/Descent. Determine the descent gradient (altitude to
lose/[distance to travel in NM x 100] = descent gradient) required to meet any altitude
restrictions and fly the FPM to the corresponding angle on the flight path scale.
Crosscheck the actual altitude with the desired altitude at intermediate points during
the descent to ensure the proper dive angle is set.
20.2.3.4. Approach. Set the illumination intensity. At night or in dense weather the