User Guide Part 2

3-2 Pilots Guide
Principles of Operation
SKY497
Sensitivity Level A
Sensitivity level A consists of two criteria for displaying a
TA
:
1.The intruder aircraft enters into a cylinder of airspace surrounding your aircraft
defined by a 0.2 nmi horizontal radius and a height of ±600 ft from your aircraft.
(See figures 3-1 and 3-2.)
OR…
2.The intruder aircraft approaches your aircraft on a course that will intercept your
course within 15 or 20 seconds (within 15 seconds for a non-altitude reporting
intruder aircraft; within 20 seconds for an altitude reporting intruder aircraft).
The
SKY497
uses sensitivity level A in the following situations:
1.Your aircraft has a radio altimeter and is below 2,000 ft
AGL
.
2.Your aircraft has no radio altimeter but its retractable landing gear is down. (Sensi-
tivity level A is not used if you have fixed landing gear and no radio altimeter.)
Sensitivity Level B
Sensitivity level B consists of two criteria for displaying a
TA
:
1.The intruder aircraft enters into a cylinder of airspace surrounding your aircraft
defined by a 0.55 nmi horizontal radius and a height of ±800 ft from your aircraft.
(See figures 3-1 through 3-3.)
OR…
2.The intruder aircraft approaches your aircraft on a course that will intercept your
course within 20 or 30 seconds (within 20 seconds for a non-altitude reporting
intruder aircraft; within 30 seconds for an altitude reporting intruder aircraft).
The
SKY497
uses sensitivity level B in the following situations:
1.Your aircraft has a radio altimeter and is above 2,000 ft
AGL
.
2.Your aircraft has no radio altimeter but its retractable landing gear is up.
3.Your aircraft has fixed landing gear and no radio altimeter.
Audio Inhibit, SKY497
This audio inhibit feature prevents the aural part of
TAs
, “traffic traffic,” from being
announced during takeoff and landing in order to minimize pilot distraction. The
corresponding
TA
symbols are still displayed.
The
SKY497
uses this audio inhibit feature in the following situations:
1.Your aircraft has a radio altimeter and you’re below 400 ft
AGL
. (See figure 3-1.)
2.Your aircraft has no radio altimeter but its retractable landing gear is down. (See figure
3-2.) (Audio is not inhibited if you have fixed landing gear and no radio altimeter.)