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Pilot's Handbook of Aeronautical Knowledge

Pilotage and Dead Reckoning

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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




Fuel Consumption
Aircraft fuel consumption is frequently computed in gallons
per hour. Consequently, to determine the fuel required for a given
flight, the time required for the flight must be known. Time
in flight multiplied by rate of consumption gives the quantity
of fuel required. For example, a flight of 400 NM at a GS of
100 knots requires 4 hours. If an aircraft consumes 5 gallons
an hour, the total consumption is 4 x 5, or 20 gallons.

The rate of fuel consumption depends on many factors:
condition of the engine, propeller/rotor pitch, propeller/rotor
revolutions per minute (rpm), richness of the mixture, and
particularly the percentage of horsepower used for flight
at cruising speed. The pilot should know the approximate
consumption rate from cruise performance charts, or from
experience. In addition to the amount of fuel required for the
flight, there should be sufficient fuel for reserve.

Flight Computers
Up to this point, only mathematical formulas have been
used to determine such items as time, distance, speed, and
fuel consumption. In reality, most pilots use a mechanical
or electronic flight computer. These devices can compute
numerous problems associated with flight planning and
navigation. The mechanical or electronic computer has an
instruction book that probably includes sample problems so
the pilot can become familiar with its functions and operation.
[Figure 15-18]

Another aid in flight planning is a plotter, which is a
protractor and ruler. The pilot can use this when determining
true course and measuring distance. Most plotters have a ruler
which measures in both NM and SM and has a scale for a
sectional chart on one side and a world aeronautical chart on
the other. [Figure 15-18]


Pilotage is navigation by reference to landmarks or
checkpoints. It is a method of navigation that can be used
on any course that has adequate checkpoints, but it is more
commonly used in conjunction with dead reckoning and
VFR radio navigation.

The checkpoints selected should be prominent features
common to the area of the flight. Choose checkpoints that can
be readily identified by other features such as roads, rivers,
railroad tracks, lakes, and power lines. If possible, select
features that make useful boundaries or brackets on each
side of the course, such as highways, rivers, railroads, and
mountains. A pilot can keep from drifting too far off course
by referring to and not crossing the selected brackets. Never
place complete reliance on any single checkpoint. Choose
ample checkpoints. If one is missed, look for the next one
while maintaining the heading. When determining position
from checkpoints, remember that the scale of a sectional chart
is 1 inch = 8 SM or 6.86 NM. For example, if a checkpoint
selected was approximately one-half inch from the course
line on the chart, it is 4 SM or 3.43 NM from the course on
the ground. In the more congested areas, some of the smaller
features are not included on the chart. If confused, hold the
heading. If a turn is made away from the heading, it is easy
to become lost.

Roads shown on the chart are primarily the well-traveled
roads or those most apparent when viewed from the air.
New roads and structures are constantly being built, and
may not be shown on the chart until the next chart is issued.
Some structures, such as antennas may be difficult to see.
Sometimes TV antennas are grouped together in an area near
a town. They are supported by almost invisible guy wires.
Never approach an area of antennas less than 500 feet above
the tallest one. Most of the taller structures are marked with
strobe lights to make them more visible to a pilot. However,
some weather conditions or background lighting may make
them difficult to see. Aeronautical charts display the best
information available at the time of printing, but a pilot should
be cautious for new structures or changes that have occurred
since the chart was printed.

Dead Reckoning

Dead reckoning is navigation solely by means of computations
based on time, airspeed, distance, and direction. The products
derived from these variables, when adjusted by wind speed
and velocity, are heading and GS. The predicted heading takes
the aircraft along the intended path and the GS establishes the
time to arrive at each checkpoint and the destination. Except
for flights over water, dead reckoning is usually used with
pilotage for cross-country flying The heading and GS as
calculated is constantly monitored and corrected by pilotage
as observed from checkpoints.