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Pilot's Handbook of Aeronautical Knowledge



Table of Contents

Chapter 1, Introduction To Flying
Chapter 2, Aircraft Structure
Chapter 3, Principles of Flight
Chapter 4, Aerodynamics of Flight
Chapter 5, Flight Controls
Chapter 6, Aircraft Systems
Chapter 7, Flight Instruments
Chapter 8, Flight Manuals and Other Documents
Chapter 9, Weight and Balance
Chapter 10, Aircraft Performance
Chapter 11, Weather Theory
Chapter 12, Aviation Weather Services
Chapter 13, Airport Operation
Chapter 14, Airspace
Chapter 15, Navigation
Chapter 16, Aeromedical Factors
Chapter 17, Aeronautical Decision Making




Cross-check. The first fundamental skill of instrument flight,
also known as "scan," the continuous and logical observation
of instruments for attitude and performance information.

Cruise clearance. An ATC clearance issued to allow a
pilot to conduct flight at any altitude from the minimum
IFR altitude up to and including the altitude specified in the
clearance. Also authorizes a pilot to proceed to and make an
approach at the destination airport.

Current induction. An electrical current being induced into,
or generated in, any conductor that is crossed by lines of flux
from any magnet.

DA. See decision altitude.

Datum (Reference Datum). An imaginary vertical plane
or line from which all measurements of arm are taken. The
datum is established by the manufacturer. Once the datum
has been selected, all moment arms and the location of CG
range are measured from this point.

D.C. Direct current.

Dark adaptation. Physical and chemical adjustments of the
eye that make vision possible in relative darkness.

Dead reckoning. Navigation of an airplane solely by means
of computations based on airspeed, course, heading, wind
direction and speed, groundspeed, and elapsed time.

Deceleration error. A magnetic compass error that occurs
when the aircraft decelerates while flying on an easterly
or westerly heading, causing the compass card to rotate
toward South.

Decision altitude (DA). A specified altitude in the precision
approach, charted in feet MSL, at which a missed approach
must be initiated if the required visual reference to continue
the approach has not been established.

Decision height (DH). A specified altitude in the precision
approach, charted in height above threshold elevation,
at which a decision must be made either to continue the
approach or to execute a missed approach.
Deice. The act of removing ice accumulation from an
aircraft structure.

Delta. A Greek letter expressed by the symbol to indicate
a change of values. As an example, CG indicates a change
(or movement) of the CG.

Density altitude. Pressure altitude corrected for nonstandard
temperature. Density altitude is used in computing the
performance of an aircraft and its engines.

Departure procedure (DP). Preplanned IFR ATC departure,
published for pilot use, in textual and graphic format.

Deposition. The direct transformation of a gas to a solid
state, in which the liquid state is bypassed. Some sources use
sublimation to describe this process instead of deposition.

Detonation. The sudden release of heat energy from fuel in
an aircraft engine caused by the fuel-air mixture reaching
its critical pressure and temperature. Detonation occurs as a
violent explosion rather than a smooth burning process.

Deviation. A magnetic compass error caused by local
magnetic fields within the aircraft. Deviation error is different
on each heading.

Dew. Moisture that has condensed from water vapor. Usually
found on cooler objects near the ground, such as grass, as
the near-surface layer of air cools faster than the layers of
air above it.

Dewpoint. The temperature at which air reaches a state where
it can hold no more water.

DGPS. Differential global positioning system.

DH. See decision height.

Differential ailerons. Control surface rigged such that the
aileron moving up moves a greater distance than the aileron
moving down. The up aileron produces extra parasite drag
to compensate for the additional induced drag caused by
the down aileron. This balancing of the drag forces helps
minimize adverse yaw.

Differential Global Positioning System (DGPS). A system
that improves the accuracy of Global Navigation Satellite
Systems (GNSS) by measuring changes in variables to
provide satellite positioning corrections.

Differential pressure. A difference between two pressures.
The measurement of airspeed is an example of the use of
differential pressure.

Dihedral. The positive acute angle between the lateral
axis of an airplane and a line through the center of a wing
or horizontal stabilizer. Dihedral contributes to the lateral
stability of an airplane.