RPZ —runway protection zone RQRD —required RRH —remote reading hygrothermometer RRHS —remote reading hydrometer RRL —runway remaining lights RRWDS —remote radar weather display RRWSS —RWDS sensor site RSA —runway safety area RSAT —runway safety action team RSR —en route surveillance radar RSS —remote speaking system RSVN —reservation RT —right turn; remote transmitter RT & BTL —radar tracking and beacon tracking level RTAD —remote tower alphanumerics display RTCA —Radio Technical Commission for Aeronautics RTE —route RTP —regional transportation plan RTR —remote transmitter/receiver RTRD —remote tower radar display RTS —return to service RUF —rough RVR —runway visual range RVRM —runway visual range midpoint RVRR —runway visual range rollout RVRT —runway visual range touchdown RW —runway RWDS —same as RRWDS RWP —real-time weather processor RWY —runway 

## S 

S —south S/S —sector suite SA —sand, sanded SAC —Strategic Air Command SAFI —semi-automatic flight inspection SALS —short approach lighting system SAT —Saturday SATCOM —satellite communications SAWR —Supplementary Aviation Weather Reporting Station SAWRS —Supplementary Aviation Weather Reporting System SB —southbound SBGP —state block grant program SCC —System Command Center SCVTS —Switched Compressed Video Telecommunications Service SDF —simplified directional facility; simplified direction finding; software defined network SDIS —switched digital integrated service SDP —service delivery point 

SD-ROB —radar weather report SDS —switched data service SE —southeast SEL —single event level SELF —simplified short approach lighting system with sequenced flashing lights SFAR-38 —Special Federal Aviation Regulation 38 SFL —sequence flashing lights SHPO —State Historic Preservation Officer SIC —service initiation charge SID — standard instrument departure; station identifier SIGMET —significant meteorological information SIMMOD —airport and airspace simulation model SIMUL —simultaneous SIP —state implementation plan SIR —packed or compacted snow and ice on runway(s) SKED —scheduled SLR —slush on runway(s) SM —statute miles SMGC —surface movement guidance and control SMPS —sector maintenance processor subsystem SMS —safety management system; simulation modeling system SN —snow SNBNK —snowbank(s) caused by plowing SNGL —single SNR —signal-to-noise ratio, also: S/N SOAR —system of airports reporting SOC —service oversight center SOIR —simultaneous operations on intersecting runways SOIWR —simultaneous operations on intersecting wet runways SPD —speed SRAP —sensor receiver and processor SSALF —simplified short approach lighting system with sequenced flashers SSALR —simplified short approach lighting system with runway alignment indicator lights SSALS —simplified short approach lighting system SSB —single side band SSR —secondary surveillance radar STA —straight-in approach STAR —standard terminal arrival route STD —standard STMUX —statistical data multiplexer STOL —short takeoff and landing SUN —Sunday SURPIC —surface picture SVC —service SVCA —service A SVCB —service B SVCC —service C 

