information at airports without operating control towers. 

(Refer to AIM.) 

SEGMENTS OF AN INSTRUMENT APPROACH PROCEDURE- An instrument approach procedure may have as many as four separate segments depending on how the approach procedure is structured. 

a. Initial Approach- The segment between the initial approach fix and the intermediate fix or the point where the aircraft is established on the intermediate course or final approach course. 

(See ICAO term INITIAL APPROACH SEGMENT.) 

b. Intermediate Approach- The segment between the intermediate fix or point and the final approach fix. 

(See ICAO term INTERMEDIATE APPROACH SEGMENT.) 

c. Final Approach- The segment between the final approach fix or point and the runway, airport, or missed approach point. 

(See ICAO term FINAL APPROACH SEGMENT.) 

d. Missed Approach- The segment between the missed approach point or the point of arrival at decision height and the missed approach fix at the prescribed altitude. 

(Refer to 14 CFR Part 97.) 

(See ICAO term MISSED APPROACH PROCEDURE.) 

SEPARATION- In air traffic control, the spacing of aircraft to achieve their safe and orderly movement in flight and while landing and taking off. 

(See SEPARATION MINIMA.) 

(See ICAO term SEPARATION.) 

SEPARATION [ICAO]- Spacing between aircraft, levels or tracks. 

SEPARATION MINIMA- The minimum longitudi- nal, lateral, or vertical distances by which aircraft are spaced through the application of air traffic control procedures. 

(See SEPARATION.) 

SERVICE- A generic term that designates functions or assistance available from or rendered by air traffic control. For example, Class C service would denote the ATC services provided within a Class C airspace area. 

SEVERE WEATHER AVOIDANCE PLAN (SWAP)- An approved plan to minimize the affect of severe weather on traffic flows in impacted terminal and/or ARTCC areas. A SWAP is normally implemented to provide the least disruption to the ATC system when flight through portions of airspace is difficult or impossible due to severe weather. 

SEVERE WEATHER FORECAST ALERTS- Preliminary messages issued in order to alert users that a Severe Weather Watch Bulletin (WW) is being issued. These messages define areas of possible severe thunderstorms or tornado activity. The messages are unscheduled and issued as required by the Storm Prediction Center (SPC) at Norman, Oklahoma. 

(See AIRMET.) 

(See CONVECTIVE SIGMET.) 

(See CWA.) 

(See SIGMET.) 

## SFA- 

(See SINGLE FREQUENCY APPROACH.) 

## SFO- 

(See SIMULATED FLAMEOUT.) 

## SHF- 

(See SUPER HIGH FREQUENCY.) 

SHORT RANGE CLEARANCE- A clearance issued to a departing IFR flight which authorizes IFR flight to a specific fix short of the destination while air traffic control facilities are coordinating and obtaining the complete clearance. 

SHORT TAKEOFF AND LANDING AIRCRAFT (STOL)- An aircraft which, at some weight within its approved operating weight, is capable of operating from a runway in compliance with the applicable STOL characteristics, airworthiness, operations, noise, and pollution standards. 

(See VERTICAL TAKEOFF AND LANDING AIRCRAFT.) 

## SIAP- 

(See STANDARD INSTRUMENT APPROACH PROCEDURE.) 

## SID- 

(See STANDARD INSTRUMENT DEPARTURE.) 

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 

