Beechcraft C-12C, Operator And Technical Reference Manual

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TM 1-1520-218-10
3C-212
threat, but are displayed to assist the flight crew in
visually acquiring the intruders.
(4) Traffic Advisory Traffic . TA aircraft are
displayed as yellow solid circles. At the time an
intruder is upgraded to a TA, the aural alert, "Traffic,
Traffic" is annunciated. A TA is an aircraft that is
within the limits from the CPA shown in Table 3C-112.
This gives the crew time to visually acquire the
intruding aircraft. No maneuvers will be commanded
by the TCAS during this time. TA traffic may be
upgraded to RA traffic, depending upon the intruders
flight path.
Table 3C-112. Traffic Advisory Chart
ALTITUDE (FEET) SECONDS TO CPA
Up to 1000 AGL 20
1000 – 2350 AGL 25
2350 AGL – 5000 BARO 30
5000 – 10,000 BARO 40
10,000 – 20,000 BARO 45
20,000 – Above BARO 48
The upgraded traffic advisory is displayed as a
solid, red, square. At this time, the intruder is
upgraded to an RA
and an aural alert, advising flight
action, is initiated. The aural alert varies on the action
required to achieve maximum vertical separation
between your aircraft and the intruder. Refer to Table
3C-111 for aural alert messages. Intruders become a
threat and an RA issued when the limits in Table
3C-113 are exceeded.
Table 3C-113. Resolution Advisory Chart
ALTITUDE (FEET) SECONDS TO CPA
Below 900 AGL RA not issued if
descending
Below 1100 AGL RA not issued if
climbing
1000 – 2350 AGL 15
2350 AGL – 5000 BARO 20
5000 – 10,000 BARO 25
10,000 – 20,000 BARO 30
20,000 – Above BARO 35
(5) Resolution Advisory Display . RA
maneuver guidance symbols are red and green arcs
superimposed on the vertical speed scale of the
vertical speed indicator.
Two types of RA's may be displayed, a
preventive and a corrective. A preventive advisory
indicates a vertical speed range or pitch that is to be
avoided while maintaining the present flight path. A
corrective advisory indicates a necessary change in
flight path by displaying a vertical speed range or pitch
to be flown to. Either advisory serves to ensure that
the maximum separation between the aircraft and an
intruder is maintained. Refer to Table 3C-114.
Table 3C-114. Resolution Advisory Inhibits
Radio Altitude Resolution Advisory
Status
Below 1450 FT AGL INCREASE DESCENT
RA inhibited
Below 1000 FT AGL
descending; Below
1200 FT AGL climbing
DESCEND RA inhibited
Below 900 FT AGL
descending; Below
1100 FT AGL climbing All RA's inhibited (TA
ONLY) and TA Aural
Message inhibited.
(a) Preventive Advisory . The preventive
advisory is an RA that occurs when the TCAS has
determined that a threat exists, but that the current
vertical speed or pitch will result in sufficient
separation from the intruder. The general conditions
for a preventive advisory occur when the intruder is
within 300 to 800 feet (relative altitude), the range
separation is decreasing, and there are approximately
25 seconds to the CPA. The RA display will show a
red vertical-speed arc indicating speeds or pitches to
avoid. No other action is advised.
(b) Corrective Advisory . This is an RA
that occurs when the TCAS has determined that the
flight crew should take action to change vertical speed
or pitch to avoid an intruder.
1 This advisory occurs when the
threat aircraft is within 300 feet (relative altitude), the
range separation is decreasing, and there are
approximately 25 seconds to the closest point of
approach. The TCAS will provide the flight crew with a
recommended vertical speed or pitch to provide
maximum aircraft separation at the closest point of
approach. The corrective advisory consists of one or
two red arcs and a green arc. As with the preventive
advisory, the red represents vertical speed or pitch
ranges that are to be avoided.
2 The pilot should act on the
corrective advisory command within approximately
5 seconds after it is issued. Strengthened (increased
climb or increased descents) resolution advisories or