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Pilot/Controller Glossary 

6/17/21 

SIDESTEP MANEUVER

 A visual maneuver 

accomplished by a pilot at the completion of an 
instrument approach to permit a straight-in landing 
on a parallel runway not more than 1,200 feet to either 
side of the runway to which the instrument approach 
was conducted. 

(Refer to AIM.) 

SIGMET

  A weather advisory issued concerning 

weather significant to the safety of all aircraft. 
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 (SDF)

 

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 CLOSE PARALLEL AP-
PROACHES

 A simultaneous, independent 

approach operation permitting ILS/RNAV/GLS 
approaches to airports having parallel runways 
separated by at least 3,000 feet and less than 
4,300

feet between centerlines. Aircraft are permit-

ted to pass each other during these simultaneous 
operations.  Integral parts of a total system are radar, 
NTZ monitoring with enhanced FMA color displays 
that include aural and visual alerts and predictive 
aircraft position software, communications override, 
ATC procedures, an Attention All Users Page 
(AAUP), PRM in the approach name, and 
appropriate ground based and airborne equipment. 
High update rate surveillance sensor required for 
certain runway or approach course separations. 

SIMULTANEOUS (CONVERGING) DEPEND-
ENT APPROACHES- An approach operation 
permitting ILS/RNAV/GLS approaches to runways 
or missed approach courses that intersect where 
required minimum spacing between the aircraft on 
each final approach course is required. 

SIMULTANEOUS (CONVERGING) INDEPEND-
ENT APPROACHES- An approach operation 
permitting ILS/RNAV/GLS approaches to non-par-
allel runways where approach procedure design 
maintains the required aircraft spacing throughout 
the approach and missed approach and hence the 
operations may be conducted independently. 

SIMULTANEOUS ILS APPROACHES

 An 

approach system permitting simultaneous ILS 
approaches to airports having parallel runways 
separated by at least 4,300 feet between centerlines. 
Integral parts of a total system are ILS, radar, 
communications, ATC procedures, and appropriate 
airborne equipment. 

(See PARALLEL RUNWAYS.) 
(Refer to AIM.) 

SIMULTANEOUS OFFSET INSTRUMENT 
APPROACH (SOIA)

 An instrument landing 

system comprised of an ILS PRM, RNAV PRM or 
GLS PRM approach to one runway and an offset 
LDA PRM with glideslope or an RNAV  PRM or 
GLS 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. Simultaneous close 
parallel PRM approach procedures apply up to the 
point where the approach course separation becomes 
3,000 feet, at the offset MAP. From the offset MAP 

PCG S