TM 55-4920-414-13&P
1-8. Description
a. The test set (Figure 1- 1) is comprised of two major assem-
blies: the Teat Box and the Teat Fixture. The Teat Fixture con-
sists of a Chassis assembly, a Manifold assembly, and a Pilot
Assist Hydraulic Module assembly.
b. The Test Box components are contained in a bench-top en-
closure equipped with a tilt stand for ease of viewing the front
panel controls and indicators.
c. Four accessory cables are stored behind a hinged door in
a cable storage compartment at the rear panel of the Teat Box,
These cables are:
(1) AC power cable (part No. 70700-20646-042).
(2) DC power cable (part No. 70700-20633-041).
(3) Pitch Trim Actuator cable (part No. 70700-20682-041).
d. Roll SAS cable (part No. 70700-20682-042).
e. Part Number 70700-30675-041, NSN 4920-01-088-3226 is
the total “Pilot Assist Nulling Test Set.” It consists of the fol-
lowing parts:
(1) 70700-20678-041
(2) 70700-20646-042
(3) 70700-20676-042
(4) 70700-20676-044
(5) 70700-20676-046
(6) 70700-20677-041
(7) 70700-20682-041
(8) 70700-20682-042
Electronic Indicator/control box
Cable Assy
Block Assy
Teat Block Assy
Test Block Assy
Chassis Assy
Cable Assy
Cable Assy
f. The rear panel of the Teat Box also contains four hard
mounted cables used to connect electrically with the Pilot As-
sist Hydraulic Module on the Teat Fixture during normal oper-
ation. An additional receptacle (J3), at the rear panel of the Test
Box, provides the means for electrical connection to the servo
components under test using appropriate cables (stowed in the
rear panel compartment).
g. The front panel of the Test Box contains input power
receptacles (J1 and J2), and the controls, indicators and test
jacks necessary for performing and monitoring results of the
various testing and nulling procedures. Test jacks on the front
panel provide the test points for checking internal power sup-
ply status.
h. The Test Fixture consists of three subassemblies: Chas-
sis assembly, Manifold assembly, and Pilot Assist Hydraulic
Module assembly. The Test Fixture provides the facilities for
mounting the servo components under test while providing the
means for selective application of pressurized hydraulic fluid
using electrical control signals from the Test Box.
i. While the Pilot Assist Hydraulic Module assembly is a
necessary operating component of the Test Fixture, it is
equipped with quick-disconnect hydraulic fittings and electri-
cal connectors for easy removal. The Test Fixture pilot assist
module is removed from the Test Fixture manifold when an off-
equipment module is to be tested in its place.
j. The Test Fixture manifold assembly accepts hydraulic
pressure and return lines from the external hydraulic test
stand at indicated ports located at the Test Fixture manifold
rear. The Test Fixture manifold distributes the pressurized hy-
draulic fluid to the Pilot Assist Hydraulic Module assembly
which, under electrical signal command from the Test Box,
routes the fluid to the appropriate parts at the front apron of
the Test Fixture manifold, The Test Fixture manifold block is
internally channelized to direct the pressurized hydraulic flu-
id, using electrically operated valves, from the Pilot Assist Hy-
draulic Module assembly to the selected servo under test.
Servo components under test are placed on the appropriate
Test Fixture chassis track and pushed forward to mate with
the self-sealing hydraulic couplings provided on the Test Fix-
ture manifold. Servo component under test are electrically in-
terconnected with the Test Box using special cables (stored in
Test Box).
1-9. Equipment Data.
Refer to Table 1-1 for equipment data,
1-2
