AADS Preliminary Test

9-1270-219-13&P

5-5.

AADS Preliminary Test. Perform

Bonding

Set S16 to HTR CCHK and

b. H e a t e r

Test.

with

the

Digital

Voltmeter

(DVM)

set

Resistance

Test,

shown

figure

5-1,

using

the

ohms check that the resistance between test

Multimeter set to the lowest resistance range. Check that

p o i n t s 15 (+ve) and 16 on the Test Set is

t h e resistance between the pitot head and the helicopter

87 ohms + 10 ohms.

bonding point on the AADS body is less than 0.2 ohm.

5-6.

AADS

Functional

Tests.

Temperature Sensor Initial Check.

(1) Set S16 to TEMP and with the Digital

a. A n g u l a r O u t p u t s A c c u r a c y T e s t .

Voltmeter set to Ohms check that the

resistance between test points 15 (+ve)

a n d 16 on the test set is 500 200

(1)

C o n n e c t the AADS for test as shown

ohms.

in figure 5-2. Set test set switches CB1

and CB2 to ON and check that the

associated

indicator

lamps

illuminate.

d. Static Pressure Leak Test.

L o c a t e pitot head in clamped position

(2)

i n checking fixture as shown in figure

(1) Set test set switches CB1 and CB2 to

5-3.

OFF.

Remove

the

interconnection

harness from the AADS and release

the

pitot

head

from

the

clamped

Set S16 to Sin ∝ a n d u s i n g t h e D V M

(3)

position.

set to dc volts measure and record the

voltage

across

test

points

(2) Loosen the two threaded joints of the

(positive lead) and TP 16 (negative

pitot

head

adaptor

(fig.

1-34)

lead) on the Test Set. (See fig. 1-32).

t u r n i n g the components of the adapter

turn

counterclockwise.

through

Set S16 to Cos ∝ and using the DVM

(4)

set to dc volts measure and record the

(3) Push the pitot head adapter over the

voltage across test points 15 (+ve) and

p i t o t head until resistance is felt and

16 on the Test Set.

tighten

the

adapter

handtight.

See

figure 5-6.

Verify that the combination plot of

(5)

the values obtained at (3) and (4)

( 4 ) S c r e w t h e a d a p t e r s i n t o t h e PT a n d PS

above lies within the specified pass

connectors on the body of the AADS.

band of figure 5-4.

(5)

Connect

the

pneumatic

circuit

shown

in figure 5-6.

Set

S16

Sin

and

using

the

(6)

DVM set to dc volts measure and

r e c o r d the voltage between test points

(6)

the

capacity

tank

vent

and

15 (+ve) and 16 on the Test Set.

shut-off valves. Close the tester vent

valve and open the pressure source

valve. Apply a pressure of 255 - 265

Set

S16

Cos

and

using

the

(7)

Kn (3.2-3.5 in. Hg).

DVM set to dc volts measure and

r e c o r d the voltage between test points

(7)

Open

the

capacity

tank

shut-off

15 (+ve) and 16 on the Test Set.

valve.

Verify that the combination plot of

(8) Start the stopwatch when the pressure

(8)

falls to 250 kn (3.1 in. Hg) and check

the values obtained at tests (6) and (7)

that after 110 seconds the pressure is

above lies within the specified pass

more than 50 kn (0.12 in. Hg).

band of figure 5-5.

5-3