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Instrument Flying Handbook
Navigation Systems
Traditional Navigation Systems

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Instrument Flying


Table of Contents

Chapter 1. Human Factors
Chapter 2. Aerodynamic Factors
Chapter 3. Flight Instruments
Chapter 4. Section I
Airplane Attitude Instrument
Using Analog Instrumentation
Chapter 4. Section II
Airplane Attitude Instrument
Using an Electronic Flight

Chapter 5. Section I
Airplane Basic
Flight Maneuvers
Using Analog Instrumentation
Chapter 5. Section II
Airplane Basic
Flight Maneuvers
Using an Electronic Flight

Chapter 6. Helicopter
Attitude Instrument Flying

Chapter 7. Navigation Systems
Chapter 8. The National
Airspace System

Chapter 9. The Air Traffic
Control System

Chapter 10. IFR Flight
Chapter 11. Emergency

The track outbound, the same principles apply: needle moving
left = wind from the left, needle moving tight = wind from the
right. Wind correction is made toward the needle deflection.
The only exception is while the turn to establish the WCA is
being made, the direction of the azimuth needle deflections is
reversed. When tracking inbound, needle deflection decreases
while turning to establish the WCA, and needle deflection
increases when tracking outbound. Note the example of
course interception and outbound tracking in Figure 7-8.

Intercepting Bearings
ADF orientation and tracking procedures may he applied to
intercept a specified inbound or outbound MB. To intercept
an inbound bearing of 355°, the following steps may he used.
(Figure 7-9]

Determine your position in relation to the station by
paralleling the desired inbound bearing. in this case,
turn to a heading of 355°, Note that the station is to
the right front of the aircraft.

2. Determine the number of degrees of needle deflection
from the nose of the aircraft. In this case, the needle's
RB from the aircraft's nose is 40° to the right. A rule
of thumb for interception is to double this RB amount
as an interception angle (80°).

3. Turn the aircraft toward the desired MB the number of
degrees determined for the interception angle which
as indicated (in two above) is twice the initial RB
(40°), or in this ease 80°. Therefore, the right turn will
be 80° from the initial MB of 355° or a turn to 075°
magnetic (355° + 80° + 075°).

4. Maintain this interception heading of 075° until the
needle is deflected the same number of degrees "left"
from the zero position as the angle of interception
080° (minus any lead appropriate for the rate at which
the bearing is changing).

5. Turn left 80° and the RB (in a no wind condition and
with proper compensation for the rate of the ADF
needle movement) should be 0°, or directly off the
nose. Additionally, the MB should he 355° indicating
proper interception of the desired course.

NOTE: The rate of an ADF needle movement or any bearing
pointer for that matter will he faster as aircraft position
becomes closer to the station or waypoint (WP).

Interception of en outbound MB can be accomplished by the
same procedures as for the inbound intercept, except that
it is necessary to substitute the 180° position for the zero
position on the needle.

Operational Errors of ADF
Some of the common pilot-induced errors associated with
ADF navigation are listed below to help you avoid making
the same mistakes. The errors are:

1. Improper tuning and station identification. Many pilots
have made the mistake of homing or tracking to the
wrong station.

2. Positively identifying any malfunctions of the RMI
slaving system or ignoring the warning flag.

3. Dependence on homing rather than proper tracking.
This commonly results from sole reliance on the ADF
indications, rather than correlating them with heading

4. Poor orientation, due to failure to follow proper steps
in orientation and tracking.

5. Careless interception angles, very likely to happen if
you rush the initial orientation procedure.

6. Overshooting and undershooting predetermined MBs,
often due to forgetting the course interception angles

7. Failure to maintain selected headings. Any heading
change is accompanied by an ADF needle change.
The instruments must be read in combination before
any interpretation is made.

8. Failure to understand the limitations of the ADF and
the factors that affect its use,

9. Over controlling track corrections close to the station
(chasing the AUF needle), due to failure to understand
or recognize station approach.

10. Failure to keep the heading indicator set so it agrees
with the magnetic compass.

Very High Frequency Omnidirectional Range (VOR)
VOR is the primary navigational aid (NAVAID) used by civil
aviation in the National Airspace System (NAS). The VOR
ground station is oriented to magnetic north and transmits
azimuth information to the aircraft, providing 360 courses
TO or FROM the VOR station. When DME is installed with
the VOR, it is referred to as a VOR/DME and provides both
azimuth and distance information. When military tactical air
navigation (TACAN) equipment is installed with the VOR,
it is known as a VORTAC and provides both azimuth and
distance information.