Occluded front Occurrence marked by a cold front overtaking a warm front and
forcing the warm front aloft as the first cold front approaches another cold front.
Omni From the Latin word omnis, meaning "all."
Plotting The primary method of determining geographical position.
Position An identifiable location on earth or a point within a man-made system of
artificial coordinates.
Precision Approach Path Indicator (PAPI) Installed on the left side of the runway,
allowing the pilot to see a single row of either two or four lights.
Prime Meridian A line that runs from the North to South Pole through Greenwich,
England and serves as the starting line for measuring longitude.
Precipitation Any product of the condensation of atmospheric water vapor that falls to
the earth s surface.
Relative Bearing (RB) The angle measured from the longitudinal axis of the aircraft
clockwise to a line passing through an object.
Restricted area Airspace established under 14 CFR part 73 provisions within which
the flight of aircraft, while not wholly prohibited, is subject to restriction.
Runway Centerline Lights (RCL) Provide visual aid to help the pilot keep the aircraft
centered on the runway during takeoff and after landing at night or in reduced visibility
conditions.
Runway end identification (identifier) lights (REIL) Provide the pilot with rapid,
positive identification of the runway threshold during an approach for landing.
Runway edge lights Form the outline of the runway for night operations or during
periods of reduced visibility.
Runway wave-off lights Six lights--three along each side of the runway in the
touchdown area--that present a high-intensity red flashing signal to inform the
approaching pilot to execute an emergency wave-off or missed approach procedure.
Stationary front Occurs when opposing forces of different air masses show little or
no movement.
Stratocumulus clouds Large, dark and rounded masses, usually in groups, lines, or
waves.
Stratus clouds Flat, shapeless, dull gray, and uniform layer of clouds.
Storm (Force Winds) Condition I Indicates that non-thunderstorm sustained winds
of 48 knots or greater are expected within 12 hours.
Storm (Force Winds) Condition II Indicates that non-thunderstorm sustained winds
of 48 knots or greater are expected within 24 hours.
Taxiway edge lights Blue lights with variable spacing related to the length of a
straight segment of a taxiway or the radius of curvature on a taxiway turn.
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