User's Manual

Chapter 4 – Principles of Operation
SKY899 Pilot’s Guide
4-3
Preliminary
The SKY899 uses sensitivity level A in the following situations
(corresponds to numbers
1, 2, 5, 6, 13, and 14 in table 4-1):
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.
3. Your aircraft has no radio altimeter, a fixed landing gear,
and your ground speed is available and is less than
120
knots.
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 hori-
zontal radius and a height of ±
800 ft from your aircraft.
(See figures
4-1 through 4-3.)
OR…
2. The intruder aircraft approaches your aircraft on a
course that will intercept your aircraft 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
SKY899 uses sensitivity level B in the following situations
(corresponds to numbers
3, 4, 7, 8, 9, 10, 11, and 12 in table 4-1):
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 no radio altimeter, a fixed landing gear,
and your ground speed is not available.
4. Your aircraft has no radio altimeter, a fixed landing gear,
and your ground speed is available but is greater than or
equal to
120 knots.
Sensitivity Levels