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Instrument Flying Handbook
Airplane Basic Flight Maneuvers Using Analog Instrumentation
Turns

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Instrument Flying
Handbook

Preface

Table of Contents

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

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

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
Operations

Remember the following points when making turns to
magnetic compass headings or when using the magnetic
compass as a reference for setting the heading indicator:

1. If on a north heading and a turn is started to the east
or west, the compass indication lags, or indicates a
ttIrl1 in the opposite direction.

2. If on a south heading and a turn is started toward the
east or west, the compass indication precedes the turn,
indicating a greater amount of turn than is actually
occurring.

3. When on an east or west heading, the compass
indicates correctly when starting a turn in either
direction.

4. If on an east or west heading, acceleration results in
a north turn indication; deceleration results in a south
turn indication.

5. When maintaining a north or south heading, no error
results from diving, climbing, or changing airspeed.

With an angle of bank between 15° and 18°, the amount of
lead or lag to be used when turning to northerly or southerly
headings varies with, and is approximately equal to the
latitude of the locality over which the turn is being made.
When turning to a heading of north, the lead for roll-out must
include the number of degrees of change of latitude, plus the
lead normally used in recovery from turns. During a turn to
a south heading, maintain the turn until the compass passes
south the number of degrees of latitude, minus normal roll-
out lead. [Figure 5-35]

For example, when turning from an easterly direction to
north, where the latitude is 30°, start the roll-out when the
compass reads 37° (30° plus one-half the 15° angle of bank,
or whatever amount is appropriate for the rate of roll-out).
When turning from an easterly direction to south, start the
rollout when the magnetic compass reads 203° (180° plus
30° minus one-half the angle of bank). When making similar
turns from a westerly direction, the appropriate points at
which to begin the roil-out would be 323° for a turn to north,
and 157° for a turn to south.

When turning to a heading of east or west from a northerly
direction, start the roll-out approximately 10° to 12° before
the east or west indication is reached. When turning to an
east or west heading from a southerly direction, start the
rollout approximately 5° before the east or west indication
is reached. When turning to other headings the lead or lag
must he interpolated.

Abrupt changes in attitude or airspeed and the resulting erratic
movements of the compass card make accurate interpretations
of the instrument very difficult. Proficiency in compass turns
depends on knowledge of compass characteristics, smooth
control technique, and accurate bank-and-pitch control.

North and South Turn Error.
Figure 5-35. North and South Turn Error.

Steep Turns
For purposes of instrument flight training in conventional
airplanes, any turn greater than a standard rate is considered
steep. [Figure 5-36] The exact angle of bank at which a
normal turn becomes steep is unimportant. What is important
is learning to control the airplane with bank attitudes in
excess of those normally used on instruments. Practicing
steep turns will not only increase proficiency in the basic
instrument flying skills, but also enable smooth, quick, and
confident reactions to unexpected abnormal flight attitudes
under instrument flight conditions.

Pronounced changes occur in the effects of aerodynamic
forces on aircraft control at progressively greater bank
attitudes. Skill in cross-check., interpretation, and control is
increasingly necessary in proportion to the amount of these
changes, though the techniques for entering, maintaining, and
recovering from the turn are the same in principle for steep
turns as for shallower turns.

 
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