SAA- (See SPECIAL ACTIVITY AIRSPACE.) 

SAFETY ALERT- A safety alert issued by ATC to aircraft under their control if ATC is aware the aircraft is at an altitude which, in the controller's judgment, places the aircraft in unsafe proximity to terrain, obstructions, or other aircraft. The controller may discontinue the issuance of further alerts if the pilot advises he/she is taking action to correct the situation or has the other aircraft in sight. 

a. Terrain/Obstruction Alert- A safety alert issued by ATC to aircraft under their control if ATC is aware the aircraft is at an altitude which, in the controller's judgment, places the aircraft in unsafe proximity to terrain/obstructions; e.g., “Low Altitude Alert, check your altitude immediately.” 

b. Aircraft Conflict Alert- A safety alert issued by ATC to aircraft under their control if ATC is aware of an aircraft that is not under their control at an altitude which, in the controller's judgment, places both aircraft in unsafe proximity to each other. With the alert, ATC will offer the pilot an alternate course of action when feasible; e.g., “Traffic Alert, advise you turn right heading zero niner zero or climb to eight thousand immediately.” 

Note: The issuance of a safety alert is contingent upon the capability of the controller to have an awareness of an unsafe condition. The course of action provided will be predicated on other traffic under ATC control. Once the alert is issued, it is solely the pilot's prerogative to determine what course of action, if any, he/she will take. 

SAFETY LOGIC SYSTEM- A software enhance- ment to ASDE-3, ASDE-X, and ASSC, that predicts the path of aircraft landing and/or departing, and/or vehicular movements on runways. Visual and aural alarms are activated when the safety logic projects a potential collision. The Airport Movement Area Safety System (AMASS) is a safety logic system enhancement to the ASDE-3. The Safety Logic System for ASDE-X and ASSC is an integral part of the software program. 

## SAFETY LOGIC SYSTEM ALERTS- 

a. ALERT- An actual situation involving two real safety logic tracks (aircraft/aircraft, aircraft/vehicle, 

## S 

or aircraft/other tangible object) that safety logic has predicted will result in an imminent collision, based upon the current set of Safety Logic parameters. 

1. Alerts generated by one or more false surface-radar targets that the system has interpreted as real tracks and placed into safety logic. 

2. Alerts in which the safety logic software did not perform correctly, based upon the design specifications and the current set of Safety Logic parameters. 

3. The alert is generated by surface radar targets caused by moderate or greater precipitation. 

c. NUISANCE ALERT- An alert in which one or more of the following is true: 

1. The alert is generated by a known situation that is not considered an unsafe operation, such as LAHSO or other approved operations. 

2. The alert is generated by inaccurate secon- dary radar data received by the Safety Logic System. 

3. One or more of the aircraft involved in the alert is not intending to use a runway (for example, helicopter, pipeline patrol, non-Mode C overflight, etc.). 

d. VALID NON-ALERT- A situation in which the safety logic software correctly determines that an alert is not required, based upon the design specifications and the current set of Safety Logic parameters. 

e. INVALID NON-ALERT- A situation in which the safety logic software did not issue an alert when an alert was required, based upon the design specifications. 

SAIL BACK- A maneuver during high wind conditions (usually with power off) where float plane movement is controlled by water rudders/opening and closing cabin doors. 

SAME DIRECTION AIRCRAFT- Aircraft are operating in the same direction when: 

a. They are following the same track in the same direction; or 

b. Their tracks are parallel and the aircraft are flying in the same direction; or 

c. Their tracks intersect at an angle of less than 45 degrees. 

b. FALSE ALERT- 

