(41)
Test the servo-pneumatic altitude indicators.
NOTE: The following steps test the barometric correction and
____ pneumatic portions of the altimeters. The servo operated portions are tested as part of the CADC test.
(a) Operate pneumatic test set to provide a pressure of 29.92 inches of mercury in static systems.
EFFECTIVITY
ALL 19 Page 517 Sep 25/9434-12-00
(b) Set CADC-STBY switches on captain's and first officer's
altitude indicators to STBY position and note that STBY flags
appear and internal vibrators turn on.
(c) Adjust BARO set knobs on both altitude indicators such that
inches-of-mercury readout counters display value shown for
test point one in Fig. 505.
(d) Note that barometer scale settings and altitude readings are
within tolerances of Fig. 505.
(e) Repeat (c) and (d) for test points two through eight in
Fig. 505.
(f) On both altitude indicators, adjust BARO set knob for a
reading of 29.92 on inches-of-mercury readout counter.
(g) Operate pneumatic test set to provide static pressure
required for test point one on Figure 506 and observe that
both altitude indicators display an altitude within tolerances
of test point one.
NOTE: Rate of pressure decrease must not exceed 3000____
feet per minute. When pressure is within 300 to
600 feet of desired test point, rate of pressure
decrease must not exceed 600 feet per minute.
(h) Repeat (g) for test points two through seven on Fig. 506; upon
completion, maintain static system pressure at 5.538 inches of
mercury (40,000 feet).
(i) Operate pneumatic test set so as to increase static pressure
at a rate corresponding to approximately 3000 feet per minute
until test point one of Fig. 507 is reached.
NOTE: Do not overshoot this point as it would cause the____
data to be inaccurate. A hysteresis test requires the
application of pressure in one direction only.
(j) Note that altitude readings on both altitude indicators do not
exceed their respective readings of altitude by more than the
tolerance specified in Fig. 507.
(k) Repeat steps (i) and (j) for test points two and three of
Fig. 507.
(l) Verify that static pressure is 29.92 inches of mercury and
that barometric correction on captain's altitude indicator
reads 29.92 inches of mercury.
(m) On autopilot/flight director mode select panel, adjust
ALT SEL control for a reading of 00000.
WARNING: BEFORE ENERGIZING AUTOPILOT BE SURE ALL CONTROL_______
SURFACES ARE FREE TO MOVE AND PERSONNEL ARE CLEAR
TO PREVENT INJURY.
(n) On pilots' overhead panel P5, verify the two master
radio switches are in ON position.
EFFECTIVITY
ALL 17 Page 518 Sep 25/9434-12-00
...........................................................................................................XA
Test Baro Scale Setting
_____Point __________________(Millibars)
1 960
2 980
3 1000
4 1013
5 1030
6 1050
Altitude Readings Min (Meters) Max
______Max
Min -461 -445 -289 -273 -119 -103
-8 + 8 +131 +147 +294 +310
Barometric Pressure Setting Error
Figure 509
Test Point 1 2 3 4 5 6
Test Set Altitude (Feet) 0 4,921 9,84319,685 29,528 39,370
Altitude Readings (Meters) 0 1,500 3,000 6,000 9,00012,000
Tolerance (Meters) | 6|11 |24 |40 |55 |70
Metric Altitude
Figure 510
EFFECTIVITY LH ALL
7XA Page 519
34-12-00
Aug 25/86
400450 500 550 600 650
RESISTANCE - OHMS
Temperature - Resistance Graph
Figure 511
EFFECTIVITY ALL
799 Page 520
34-12-00
Aug 25/92
A57310
TEST PITOT PRESS. STATIC MACH NO. ALTITUDE POINT (IN. HG. ABS.) (IN. HG) (FEET)
1 2 3 4 5 6 7 8
30.870
27.996
26.122
19.986
20.036
13.540
11.250
9.265 29.921
24.896
20.577
16.866
13.750
8.885
7.041
5.5380.212
0.413
0.594
0.497
0.754
0.800
0.850
0.900
-3 4,951 9,922 14,936 19,980 30,010 35,075 40,225
+/-+/-+/-+/-+/-+/-+/-+/-20 2530 35 35 45 55 80
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