to the runway threshold, visual separation by the  aircraft conducting the offset approach is utilized.  (Refer to AIM)  SIMULTANEOUS (PARALLEL) DEPENDENT  APPROACHES- An approach operation permitting  ILS/RNAV/GLS approaches to adjacent parallel  runways where prescribed diagonal spacing must be  maintained. Aircraft are not permitted to pass each  other during simultaneous dependent operations.  Integral parts of a total system ATC procedures, and  appropriate airborne and ground based equipment.  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 CHART SUPPLEMENT U.S.)  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.  SLDI- (See SECTOR LIST DROP INTERVAL.)  SLOT TIME- (See METER FIX TIME/SLOT TIME.)  SPECIAL EMERGENCY- A condition of air piracy  or other hostile act by a person(s) aboard an aircraft  which threatens the safety of the aircraft or its  passengers.  SPECIAL FLIGHT RULES AREA (SFRA)- An  area in the NAS, described in 14 CFR Part 93,  wherein the flight of aircraft is subject to special  (Refer to 14 CFR Part 93.)  SPECIAL AIR TRAFFIC RULES (SATR)- Rules  that govern procedures for conducting flights in  certain areas listed in 14 CFR Part 93. The term  “SATR" is used in the United States to describe the  rules for operations in specific areas designated in the  Code of Federal Regulations.  (See  EN ROUTE DECISION SUPPORT TOOL .)  SPECIAL ACTIVITY AIRSPACE (SAA)- Any  airspace with defined dimensions within the National  Airspace System wherein limitations may be  imposed upon aircraft operations. This airspace may  be restricted areas, prohibited areas, military  operations areas, air ATC assigned airspace, and any  other designated airspace areas. The dimensions of  this airspace are programmed into EDST and can be  designated as either active or inactive by screen entry.  Aircraft trajectories are constantly tested against the  dimensions of active areas and alerts issued to the  applicable sectors when violations are predicted.  SPACE-BASED ADS-B (SBA)- A constellation of  satellites that receives ADS-B Out broadcasts and  relays that information to the appropriate surveil- lance facility. The currently deployed SBA system is  only capable of receiving broadcasts from 1090ES- equipped aircraft, and not from those equipped with  only a universal access transceiver (UAT). Also,  aircraft with a top-of-fuselage-mounted transponder  antenna (required for TCAS II installations) will be  better received by SBA, especially at latitudes below  45 degrees.  (See AUTOMATIC DEPENDENT  SURVEILLANCE-BROADCAST.)  (See AUTOMATIC DEPENDENT  SURVEILLANCE-BROADCAST OUT.)  SPEAK SLOWER- Used in verbal communications  as a request to reduce speech rate.  SN- (See SYSTEM STRATEGIC NAVIGATION.)  SLOW TAXI- To taxi a float plane at low power or  low RPM.  Pilot/Controller Glossary Pilot/Controller Glossary  8/15/19 1/30/20  PCG S-5 