Autopilot/Flight Director

STUDENT GUIDE T-39N/G NATOPS

9. AOA indicator - 18 units at Vref; 24 units stall warning.

a. AOA indexers- heads-up display of AOA reference to On-Speed (18 units)

(1) Green chevron - AOA above 18 units (SLOW).

(2) Amber donut - AOA at 18 units (ON-Speed).

(3) Red chevron - AOA below 18 units (FAST).

NOTE: AOA units are NOT associated with angle of attack in degrees. It is simply an

arbitrary number for that particular aircraft.

10. RMI (pilot only) - single/double needles

a. Powered by DC essential power.

b. Single needle ADF(LF/MF) or VOR (NAVI).

c. Double needle ADF(UIIF DF) or VOR (NAV2).

d. No TACAN/DME capability.

11. Directional Indicating System (EHSI)/Magnetic compass

a. COMP 1 (pilots)/COMP 2(copilots). Normally both pilot/co-pilot will fly on

COMP2

b. Compass slave indicator - indicates difference between respective COMP and

remote compass transmitter (RCT) on respective wingtip. To manually slave

(correct) depress D/G (illuminates green) and depress respective DECR/INCR

buttons until COMP is slaved. When complete, depress D/G button again to

return to Auto Slave mode.

c. Magnetic (Standby) Compass only accurate with NO electrical power to aircraft.

Compass correction card on center windshield divider and is a correction WITH

electrical power on. (Standby compass is INACCURATE ON DECK)

K. Autopilot/Flight Director

1. Provides Altitude Hold, steering with HDG bug (pilot only), automatic radial

tracking, autopilot Localizer and ILS approaches.

2. Roll and pitch information to V-Command bars.

L. Electronic HSI

1. HSI, ARC, and MAP buttons choose the mode of display.

2. Single/Double needle buttons

a. Single needle options - V 1(NAV 1), Al (LF/W ADF), A2(UHF/DF), T 1(TACAN),

OFF(deselects needle from display).

8-4

AVIONICS SYSTEMS