Q9-14. What is the main difference between the
The Model HCT-10 test stand (fig. 9-10) is used to
bench test aircraft hydraulic and pneumatic
A/M27T-5 unit and the A/M27T-7 unit?
components, such as engine-driven hydraulic pumps,
Q9-15. W h a t p u b l i c a t i o n s u p p l i e s d e t a i l e d
electro hydraulic flight control assemblies,
information on the A/M27T-7 unit?
double-acting hydraulic cylinders, pneumatic and
hy d r a u l i c r e l i e f va l ve s , hy d r o p n e u m a t i c
Q9-16. At what level should the reservoir of a
accumulators, and other components.
hydraulic test stand be maintained?
The test stand consists of a nonportable cabinet
Q9-17. After you start a hydraulic test stand, what is
assembly that contains a hydraulic system, a
the first thing you must do?
pneumatic system, and an electrical system. It must be
Q9-18. W h a t a c t i o n s m u s t b e t a k e n p r i o r t o
connected to externally supplied electrical power,
connecting a hydraulic test stand to an
water, and compressed air. The cabinet assembly
aircraft?
consists of a welded steel enclosure on a rigid base.
Hinged doors and removable panels provide access to
Q9-19. Once you have the hoses connected to the
the interior. The test component work area is located
aircraft, what action must you take prior to
below the center instrument and control panel. The
applying hydraulic power to an aircraft?
bottom surface of the test component work area and the
test chamber is shaped like a sink with perforated metal
Q9-20. What component is used to adjust the
trays. The test chamber is made from a 1/4-inch steel
operating pressure of a hydraulic test stand?
plate with a hinged door containing a safety-type
window.
STATIONARY HYDRAULIC TEST STANDS
Most of the hydraulic and pneumatic system
Stationary hydraulic test stands are permanently
operating controls are located on a sloping panel along
installed equipment used for shop-testing hydraulic
the front of the cabinet. The indicators are located on a
system components. Except for specialized
panel above the work sink and the rear panel of the test
equipment, such as hose burst test stands, they are
chamber. The electrical system controls and indicators
general-purpose equipment capable of performing a
are located on a panel on the right-hand side of the
variety of tests on components such as hydraulic
cabinet. A partition separates the major part of the
pumps, actuators, motors, valves, accumulators, and
electrical system components from the hydraulic
gauges. Typical component test stands consist of
system.
adjustable sources of hydraulic and shaft-driven (for
pump drive) power, with associated regulator and
H Y D R AU L I C S Y S T E M . -- T h e h y d r a u l i c
indicating devices that let you monitor performance
system has two components--a reservoir, which
under simulated operating conditions. Stationary
supplies fluid through a helical, screw-type boost
hydraulic test stands are used at the
p u m p , a n d a fi l t e r t o a va r i a b l e vo l u m e ,
intermediate-maintenance level, ashore and afloat, and
pressure-compensated, axial piston, high-pressure
for depot-level maintenance.
pump. Also, the hydraulic system has three
circuits--the dynamic test circuit, the static test
Model HCT-10 Stationary Hydraulic Test
circuit, and the pump test circuit.
Stand
Dynamic Test Circuit.--The dynamic test circuit
is used to test double-acting hydraulic cylinders and
Stationary hydraulic test stands, such as the Model
other components requiring combined pressure and
HCT-10, are not part of the equipment allowance for
flow.
most squadrons. Normally, they are issued to air
stations and aircraft carriers for use by the supported
Static Test Circuit.--The static test circuit is
squadrons.
included in the hydraulic system. It is essentially a
c o m p r e s s e d a i r- o p e r a t e d , l ow - d i s p l a c e m e n t ,
NOTE: The following information is for training
high-pressure pump that supplies fluid for static
purposes only. Do not use it as operating instructions
pressure tests. This circuit may be operated
for testing hydraulic or pneumatic components. For
independently of the other two test circuits. A safety
specific operating instructions, you should refer to the
interlock prevents operation of this circuit when the
applicable operational handbook, service, and
door of the test chamber is open.
overhaul instructions, or the MIM.
9-15
