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Instrument Flying Handbook
Airplane Basic Flight Maneuvers Using an Electronic Flight Display
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

At constant power, any deviation from level flight (except
in turbulent air) must be the result of a pitch change. If the
power is constant, the altimeter gives an indirect indication
of the pitch attitude in level flight. Since the altitude should
remain constant when the airplane is in level flight, any
deviation from the desired altitude signals the need for a
pitch change. For example, if the aircraft is gaining altitude,
the nose must be lowered.

In the PFD, as the pitch starts to change, the altitude trend
indicator on the altitude tape will begin to show a change
in the direction of displacement. The rate at which the trend
indicator grows and the altimeter numbers change aids the
pilot in determining how much of a pitch change is necessary
to stop the trend.

As a pilot becomes familiar with a specific aircraft's
instruments, he or she learns to correlate pitch changes,
altimeter tapes, and altitude trend indicators. By adding the
altitude tape display and the altitude trend indicator into the
scan along with the attitude indicator, a pilot starts to develop
the instrument cross-check.

Partial Panel Flight
One important skill to practice is partial panel flight by
referencing the altimeter as the primary pitch indicator.
Practice controlling the pitch by referencing the attitude
tape and trend indicator alone without the use of the attitude
indicator. Pilots need to learn to make corrections to altitude
deviations by referencing the rate of change of the altitude
tape and trend indicator When operating in IMC and in a
partial panel configuration the pilot should avoid abrupt
changes to the control yoke. Reacting abruptly to altitude
changes can lead to large pitch changes and thus a larger
divergence from the initial altitude.

When a pilot is controlling pitch by the altitude tape and
altitude trend indicators alone, it is possible to overcontrol the
aircraft by making a larger than necessary pitch correction.
Overcontrolling will cause the pilot to move from a nose-
high attitude to a nose-low attitude and vice versa. Small
changes to pitch are required to insure prompt corrective
actions are taken to return the aircraft to its original altitude
with less confusion.

When an altitude deviation occurs, two actions need to be
accomplished. First, make a smooth control input to stop
the needle movement. Once the altitude tape has stopped
moving, make a change to the pitch attitude to start hack to
the entry altitude.

During instrument flight with limited instrumentation, it is
imperative that only small and precise control inputs are

made. Once a needle movement is indicated denoting a
deviation in altitude, the pilot needs to make small control
inputs to stop the deviation. Rapid control movements will
only compound the deviation by causing an oscillation effect.
This type of oscillation can quickly cause the pilot to become
disoriented and begin to fixate on the altitude. Fixation on
the altimeter can lead to a loss of directional control as well
as airspeed control.

As a general rule of thumb, for altitude deviations less than
100 feet, utilize a pitch change of 1°, which equates to 1/5 of
the thickness of the chevron. Small incremental pitch changes
will allow the performance to be evaluated and will eliminate
oyer controlling of the aircraft.

Instrumentation needs to be utilized collectively, but
failures will occur which leave the pilot with only limited
instrumentation. That is why partial panel flying training
is important. if the pilot understands how to utilize each
instrument independently, no significant change is encountered
in carrying out the flight when other instruments fail.

VSI Tape
The VSI tape provides for an indirect indication of pitch
attitude and gives the pilot a more immediate indication of a
pending altitude deviation. In addition to trend information,
the vertical speed also gives a rate indication. By using the
VSI tape in conjunction with the altitude trend tape, a pilot
will have a better understanding of how much of a correction
needs to be made. With practice, the pilot will learn the
performance of a particular aircraft and know how much
pitch change is required in order to correct for a specific
rate indication.

Unlike older analog VSIs, new glass panel displays have
instantaneous VSIs. Older units had a lag designed into the
system that was utilized to indicate rate information. The
new glass panel displays utilize a digital air data computer
that does not indicate a lag. Altitude changes are shown
immediately and can be corrected for quickly.

The VSI tape should be used to assist in determining what
pitch changes are necessary to return to the desired altitude.
A good role of thumb is to use a vertical speed rate of change
that is double the altitude deviation. However, at no time
should the rate of change be more than the optimum rate of
climb or descent for the specific aircraft being flown. For
example, if the altitude is off by 200 feet. from the desired
altitude, then a 400 feet per minute (fpm) rate of change
would he sufficient to get the aircraft hack to the original
altitude. If the altitude has changed by 700 feet, then doubling
that would necessitate a 1,400 fpm change. Most aircraft
are not capable of that, so restrict changes to no more than
optimum climb and descent. An optimum rate of change
would vary between 500 and 1,000 fpm.