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Instrument Flying Handbook
Airplane Basic Flight Maneuvers Using Analog Instrumentation
Straight-and-Level Flight

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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

1. Maintain rpm at 2,500, since a high power setting will
be used in full drag configuration.

2. Reduce manifold pressure to 10" Hg. As the airspeed
decreases, increase cross-check speed.

3. Make trim adjustments for an increased angle of attack
and decrease in torque.

4. Lower the gear at 115 knots. The nose may tend to
pitch down and the rate of deceleration increases.
Increase pitch attitude to maintain constant altitude,
and trim off some of the back-elevator pressures.
If full flaps are lowered at 105 knots, cross-check,
interpretation, and control must he very rapid. A
simpler technique is to stabilize attitude with gear
down before lowering the flaps.

5. Since 18" Hg manifold pressure will hold level
flight at 100 knots with the gear down, increase
power smoothly to that setting until the ASI shows
approximately 105 knots, and retrim. The attitude
indicator now shows approximately two-and-a-half
bar width nose-high in straight-and-level flight.

6. Actuate the flap control and simultaneously increase
power to the predetermined setting (25" Hg) for the
desired airspeed, and trim off the pressures necessary
to hold constant altitude and heading. The attitude
indicator now shows a bar width nose-low in straight-
and-level flight at 95 knots.

Proficiency in straight-and-level flight is attained when a
pilot can consistently maintain constant altitude and heading
with smooth pitch, bank, power, and trim control during the
pronounced changes in aircraft attitude.

Trim Technique
Proper trim technique is essential for smooth and precise
aircraft control during all phases of flight. By relieving all
control pressures, it is much easier to hold a given attitude
constant, and devote more attention to other flight deck

An aircraft is trimmed by applying control pressures to
establish a desired attitude, then adjusting the trim so the
aircraft will maintain that attitude when the flight controls are
released. Trim the aircraft for coordinated flight by centering
the ball of the turn-and-slip indicator, by using rudder trim in
the direction the ball is displaced from the center. Differential
power control on multiengine aircraft is an additional factor
affecting coordinated flight. Use balanced power or thrust,
when possible, to aid in maintaining coordinated flight.

Changes in attitude, power, or configuration will require a
trim adjustment in most cases. Using trim alone to establish
a change in aircraft attitude invariably leads to erratic aircraft
control, Smooth and precise attitude changes are best attained
by a combination of control pressures and trim adjustments.
Therefore, when used correctly, trim adjustment is an aid to
smooth aircraft control.

Common Errors in Straight-and-Level Flight

Pitch errors usually result from the following faults:

1. Improper adjustment of the attitude indicator's
miniature aircraft to the wings level attitude.
Following the initial level off from a climb, check the
attitude indicator and make any necessary adjustment
in the miniature aircraft for level flight indication at
normal cruise airspeed.

2. Insufficient cross-check and interpretation of pitch
instruments. Fur example, the airspeed indication is
low. The pilot, believing a nose-high attitude exists,
applies forward pressure without noting that a low
power setting is the cause of the airspeed discrepancy.
Increase cross-check speed to include all relevant
instrument indications before making a control input.

3. Uncaging the attitude indicator (if caging feature is
present) when the airplane is not in level flight. The
altimeter and heading indicator must he stabilized with
airspeed indication at normal cruise before pulling
out the caging knob, to obtain correct indications in
straight-and-level flight at normal cruise airspeed.

4. Failure to interpret the attitude indicator in terms of
the existing airspeed.

5. Late pitch corrections. Pilots commonly like to leave
well enough alone. When the altimeter indicates a 20
foot error, there is a reluctance to correct it, perhaps
because of fear of overcontrolling. If overcontrolling
is the anticipated error, practice small corrections and
find the cause of overcontrolling. If any deviation is
tolerated, errors will increase,

6. Chasing the vertical speed indications. This tendency.
can be corrected by proper cross-check of other
pitch instruments, as well as by increasing overall
understanding of instrument characteristics.

7. Using excessive pitch corrections for the altimeter
evaluation. Rushing a pitch correction by making a
large pitch change usually aggravates the existing
error, saving neither time nor effort.