Table 4. Rate of Climb Accuracy Check

TB 9-4920-363-24

b. Adjustments. No adjustments can be made.

Pneumatic pressure standard indications

Test instrument indications

(fpm)

Min

Max

1000

800

1200

2000

1700

2300

3000

2700

3300

4000

3600

4400

45001

4050

4950

-500

-400

-600

-1000

-800

-1200

-2000

-1700

-2300

-3000

-2700

-3300

-4000

-3600

-4400

-4500

-4050

-4950

1Maintain

climb rate indication of 4500 fpm for 3 minutes, close both vacuum control valves (fully cw), set

power switch to OFF, and proceed to -500 fpm indication.

10. Airspeed Indicator

a. Performance Check

(1) Connect pneumatic pressure standard 5 psid inlet port to TI airspeed connector,

using TI hose assembly.

(2) Set pneumatic pressure standard to indicate airspeed in knots.

(3) Position TI controls as listed in (a) through (f) below:

(a) VACUUM selector valve to OFF.

(b) PRESSURE selector valve to AIRSPEED.

(d) VACUUM INCREASE and DECREASE control valves to open position.

(e) PRESSURE INCREASE and DECREASE control valves to closed position.

(f) POWER switch to ON.

(4) Slowly adjust TI PRESSURE INCREASE and DECREASE control valves

until TI indicates 50 knots. Pneumatic pressure standard will indicate between 48 and

52 knots.

(5) Slowly adjust TI PRESSURE INCREASE and DECREASE control valves for

each TI indication as listed in table 5. Pneumatic pressure standard will indicate within

the limits specified.