STUDENT GUIDE FOR T-1A AIRCRAFT SYSTEMS
TCAS RA/VSI Indications
One RA/VSI is installed on each P's instrument panel. The TCAS resolution advisory arc
consists of numerous red/green lights around the Vertical Speed (VS) scale. Any light can be red
or green. Normally the lights are off. The TCAS illuminates portions of the arc to display
resolution advisories. Avoidance or exit VS display is a red arc. Recommended fly-to VS
display is a green arc. A red arc marks a warning VS range.
MFD TCAS Traffic Page
The MFD TCAS traffic page is a dynamic, heading up pictorial that shows nearby transponder
equipped aircraft. The page shows traffic symbols that alert the crew to potential and predicted
Range Distance - A numeric range label is displayed near the outer range ring. Full-scale
range is selectable from 2 to 50 NM. With the weather radar overlay off, the display range and
distance labels are changed by pressing the up arrow or down arrow line keys.
Aircraft Symbol - The miniature swept-wing aircraft symbol is used to visualize the
relative positions of intruder aircraft to the host aircraft. The aircraft symbol is stationary and
always displays in the center of the screen.
Range Rings - Three range rings provide a distance measuring scale. The rings show
distance from the aircraft. The outer ring is a solid circle with a tic mark every 30°. This ring
represents the selected full-scale range. The middle ring is a half intensity circle with a tic mark
every 30°. This ring marks the half scale range.
Traffic Symbol - Each traffic display consists of an intruder symbol, an Altitude Data
(ALT DATA) field, and a VS trend arrow (if applicable). The altitude and arrow displays are the
same color as the intruder symbol.
Four types of intruder symbols may be displayed:
1. A cyan open-diamond symbol shows an aircraft in the protected airspace volume (other
traffic), but is not considered to be a collision threat.
2. The cyan solid-diamond is a proximate traffic symbol that shows an aircraft nearby (+
1200 ft.), but is not close enough to be considered advisory traffic.
3. The yellow solid-circle is a TA traffic symbol. The symbol means the intruder aircraft is a
potential threat (approximately 40 seconds from minimum separation).
4. The red solid-square symbol is a RA traffic symbol. The intruder aircraft is an immediate
threat (approximately 25 seconds from minimum separation). Take corrective or preventive
action to maintain airspace separation. The RA/VSI displays the recommended corrective or
12-4 NAVIGATION RADIOS