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6/17/21 

Pilot/Controller Glossary 

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, 

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. 

b. 

FALSE ALERT

 

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. 

PCG S