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Pilot's Handbook of Aeronautical Knowledge
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Latitude and Longitude (Meridians and
Parallels)

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Pilot's Handbook of Aeronautical Knowledge

Preface

Acknowledgements

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

Appendix

Glossary

Index

Latitude and Longitude (Meridians and Parallels)

The equator is an imaginary circle equidistant from the poles
of the Earth. Circles parallel to the equator (lines running east
and west) are parallels of latitude. They are used to measure
degrees of latitude north (N) or south (S) of the equator. The
angular distance from the equator to the pole is one-fourth
of a circle or 90°. The 48 conterminous states of the United
States are located between 25° and 49° N latitude. The arrows
in Figure 15-4 labeled “Latitude” point to lines of latitude.
Meridians of longitude are drawn from the North Pole to the
South Pole and are at right angles to the Equator. The “Prime
Meridian” which passes through Greenwich, England, is
used as the zero line from which measurements are made in
degrees east (E) and west (W) to 180°. The 48 conterminous
states of the United States are between 67° and 125° W
longitude. The arrows in Figure 15-4 labeled “Longitude”
point to lines of longitude.

Any specific geographical point can be located by reference
to its longitude and latitude. Washington, D.C., for example,
is approximately 39° N latitude, 77° W longitude. Chicago
is approximately 42° N latitude, 88° W longitude.

Time Zones
The meridians are also useful for designating time zones. A
day is defined as the time required for the Earth to make one
complete rotation of 360°. Since the day is divided into 24
hours, the Earth revolves at the rate of 15° an hour. Noon is
the time when the sun is directly above a meridian; to the west
of that meridian is morning, to the east is afternoon.

VFR terminal area chart and legend.
Figure 15-2. VFR terminal area chart and legend.

 

15-4