Pilot/Controller Glossary
4/3/14
PCG S−4
SIGMET advisories cover severe and extreme
turbulence, severe icing, and widespread dust or
sandstorms that reduce visibility to less than 3 miles.
(See AIRMET.)
(See AWW.)
(See CONVECTIVE SIGMET.)
(See CWA.)
(See ICAO term SIGMET INFORMATION.)
(Refer to AIM.)
SIGMET INFORMATION [ICAO]− Information
issued by a meteorological watch office concerning
the occurrence or expected occurrence of specified
en-route weather phenomena which may affect the
safety of aircraft operations.
SIGNIFICANT METEOROLOGICAL INFOR-
MATION
−
(See SIGMET.)
SIGNIFICANT POINT− A point, whether a named
intersection, a NAVAID, a fix derived from a
NAVAID(s), or geographical coordinate expressed in
degrees of latitude and longitude, which is
established for the purpose of providing separation,
as a reporting point, or to delineate a route of flight.
SIMPLIFIED DIRECTIONAL FACILITY− A
NAVAID used for nonprecision instrument
approaches. The final approach course is similar to
that of an ILS localizer except that the SDF course
may be offset from the runway, generally not more
than 3 degrees, and the course may be wider than the
localizer, resulting in a lower degree of accuracy.
(Refer to AIM.)
SIMULATED FLAMEOUT− A practice approach
by a jet aircraft (normally military) at idle thrust to a
runway. The approach may start at a runway (high
key) and may continue on a relatively high and wide
downwind leg with a continuous turn to final. It
terminates in landing or low approach. The purpose
of this approach is to simulate a flameout.
(See FLAMEOUT.)
SIMULTANEOUS ILS APPROACHES− An
approach system permitting simultaneous ILS/MLS
approaches to airports having parallel runways
separated by at least 4,300 feet between centerlines.
Integral parts of a total system are ILS/MLS, radar,
communications, ATC procedures, and appropriate
airborne equipment.
(See PARALLEL RUNWAYS.)
(Refer to AIM.)
SIMULTANEOUS MLS APPROACHES−
(See SIMULTANEOUS ILS APPROACHES.)
SIMULTANEOUS OFFSET INSTRUMENT
APPROACH (SOIA) − An instrument landing
system comprised of an ILS PRM or RNAV (GPS)
PRM approach to one runway and an offset LDA
PRM with glideslope or an RNAV (GPS) PRM
approach utilizing vertical guidance to another where
parallel runway spaced less than 3,000 feet and at
least 750 feet apart. The approach courses converge
by 2.5 to 3 degrees. Closely spaced independent
approach procedures apply up to the point where the
approach course separation becomes 3,000 feet, at the
offset MAP. From the offset MAP to the runway
threshold, visual separation by the aircraft
conducting the offset LDA PRM or GPS PRM
approach is utilized.
(Refer to AIM)
SINGLE DIRECTION ROUTES− Preferred IFR
Routes which are sometimes depicted on high
altitude en route charts and which are normally flown
in one direction only.
(See PREFERRED IFR ROUTES.)
(Refer to AIRPORT/FACILITY DIRECTORY.)
SINGLE FREQUENCY APPROACH− A service
provided under a letter of agreement to military
single-piloted turbojet aircraft which permits use of
a single UHF frequency during approach for landing.
Pilots will not normally be required to change
frequency from the beginning of the approach to
touchdown except that pilots conducting an en route
descent are required to change frequency when
control is transferred from the air route traffic control
center to the terminal facility. The abbreviation
“SFA” in the DOD FLIP IFR Supplement under
“Communications” indicates this service is available
at an aerodrome.
SINGLE-PILOTED AIRCRAFT− A military
turbojet aircraft possessing one set of flight controls,
tandem cockpits, or two sets of flight controls but
operated by one pilot is considered single-piloted by
ATC when determining the appropriate air traffic
service to be applied.
(See SINGLE FREQUENCY APPROACH.)
SKYSPOTTER− A pilot who has received
specialized training in observing and reporting
inflight weather phenomena.
SLASH− A radar beacon reply displayed as an
elongated target.