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
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).