TB 9-4920-459-24
(12) Wait for the altitude and speed aim to be achieved then wait 1 minute.
(13) Press LEAK MEASURE/CONTROL key to select MEASURE MODE.
(14) Press RATE TIMER key and select F3; wait 5 minutes, time 1 minute.
(15) Wait until the waiting and timing is complete and check that the rate of speed
(RATE CAS) is less than 2 kts/min.
(16) If the leak rate is greater than 2 kts/min, repeat the rate timing using the 5
minute wait, 1 minute time. If still greater than 2 kts/min, then check the integrity of the
pneumatic connections, leak test the pneumatic pressure standard, and leak test the TI.
(17) Press LEAK MEASURE/CONTROL key then press the GROUND key and
select F1 to select ground, then press the ALT key.
a. Performance Check
NOTE
If TI is out of calibration at any point, go to ground then
(1) Press LEAK MEASURE/CONTROL key and select CONTROL MODE.
(2) Press SPEED key and enter a speed aim of 0 kts.
(3) Press ALT key to enter the first altitude aim from table 3.
Test
Pneumatic pressure standard
instrument
indications
indications
(ft)
(ft)
Min
Max
50,000
49,950
50,050
40,000
39,960
40,040
30,000
29,970
30,030
20,000
19,980
20,020
10,000
9,990
10,010
5,000
4,990
5,010
-10
+10
0
-1,500
-1,510
-1,490
(4) Allow the aim to be achieved and wait 1 minute to stabilize. Check that the
displayed reading of altitude on the pneumatic pressure standard is within the tolerance
(5) Repeat (3) and (4) above for remaining altitudes listed in table 3.
(6) Press GROUND key and select F1.