Airspeed indicator

STUDENT GUIDE T-39N/G NATOPS

c. Radalt will display AGL altitudes to the nearest 50 feet above 1000 feet and to the

nearest 10 feet below 1000 feet.

2. Airspeed indicator

a. Both indicators can use either pitot-static system (pilot's/co-pilot's).

b. Fixed IAS scale / movable Mach scale (controlled by aneroid diaphragm which reacts

to static pressure changes as altitude changes).

c. Mach/Airspeed audible tone when max. airspeed is exceeded.

Maximum airspeed - 350 to 365 kts, sea level to 21,500 ft.; .8 Mach above 21,500 ft.

3. Vertical Velocity Indicator (VVI / VSI)

a. " minute to live" rule - If the VSI indicates the same number as the

altimeter during a descent, this is a VERY GOOD time to reduce your rate of descent

(ie.; never have less than a "minute to live").

b. Either indicator can use either or both static systems.

4. Altimeter

a. The NORM/STBY switch on pilot's altimeter should be on NORM. STBY is not

functional in this aircraft (the co-pilot does not have this switch).

b. Transponder MODE C and Altitude Alerter uses PILOT's altimeter.

c. Either altimeter can use either or both static systems.

5. Altitude alerter - 000' to go or when 300' deviation from SET altitude. Tone and ALT

SEL light illuminates

6. Flight Director/Attitude indicator/standby (EMERG GYRO) attitude indicator.

a. Pilot's Flight Director is linked up to Auto Pilot (Integrated Flight System) to give:

(1) Pitch, Roll, and Yaw (inclinometer/slip indicator).

(2) Glideslope/ localizer deviation information.

(3) Tapered V-command bar to give roll or pitch commands to pilot via flight

computer.

b. Standby attitude gyro

(1) EMER GYRO pushbutton ON.

(2) 4 hour battery if dual gen fail.

(3) If emergency power fails, stby gyro good for 9 minutes minimum.

7. Outside air temperature - pilot or co-pilot side.

8. Clock - stopwatch, elapsed time, 24-hour clock, reset.

AVIONICS SYSTEMS 8-3