matter does not enter the strut during assembly.
Contamination of parts can cause a definite failure.
Guarding against contamination cannot be over-
Observe the torque values specified in the 03
manual or MIM. Where a specific torque value is not
specified for a threaded part, tighten the part according
to the standard torque values provided in the Structural
Hardware Manual, NAVAIR 011A8. Some structural
repair manuals and maintenance instructions manuals
also contain this information. On some parts, such as the
strut gland nut, tightening should conform to acceptable
shop practices and common sense, unless otherwise
Lightly coat all preformed packings with hydraulic
fluid. After all seals and parts are properly installed, the
piston head is tightened and the retaining pins installed
and staked into place. The piston assembly is inserted
into the outer cylinder, and the gland nut is tightened to
a snug fit, backed off two key slots, and locked in place.
If the gland nut is too tight, it will result in binding of
the thrust bearing. Two lock plates, positioned 180
degrees apart on the collar and gland nut, are secured
with screws and lockwired to hold the gland nut in place.
Use the double twist method of applying the lockwire
so that tension of the wire tends to tighten the nut.
With the strut fully compressed and in the vertical
position, service the strut with hydraulic fluid. Install the
air valve on the strut and torque to 100-110 inch-pounds.
Place the strut fully extended in a horizontal or vertical
position and inflate with dry nitrogen to the normally
extended pressure specified in the MIM or 03 manual.
Ensure that the strut shows no leakage after a 1-hour
If the strut fails the bench test, it is tagged to show
the portion of the test that failed. Then it is deflated,
flushed with preservative hydraulic fluid, and forwarded
to the next higher level of maintenance.
If the strut passes the bench test and is not to be
installed on an aircraft immediately, flush with
preservative hydraulic fluid before sending it to supply.
If any parts other than those listed as replaceable at
the intermediate level of maintenance are faulty, tag the
strut and forward it to the next higher level of
maintenance. The VIDS/MAF is closed out to account
for man-hours expended in attempting repairs before the
strut is declared beyond the capability of maintenance
(BCM). If a Quality Deficiency Report (QDR) form was
attached to the strut by the removing organizational
maintenance activity, complete the QDR and submit it
according to the instructions provided in OPNAV
Instruction 4790.2 (series).
Any unusual failure or strut malfunction should be
reported by the submission of a QDR so that failure
trend patterns or isolated instances maybe reviewed for
possible higher echelon action. Forward the No. 4 copy
of the MAF and the hard copy of the QDR with the strut
to the next higher level of maintenance.
Learning Objective: Identify the three major
brake systems and recognize the operation of
the emergency brake systems.
Three types of brake systems are currently in use on
naval aircraft. They are the independent-type brake
system, the power boost brake system, and the power
brake control valve system. In addition, there are several
different types of brake assemblies currently in use.
In general, the independent-type brake system is
used on small aircraft. This type of brake system is
termed independent because it has its own reservoir and
is entirely independent of the aircrafts main hydraulic
The independent-type brake system is powered by
master cylinders similar to those used in the con-
ventional automobile brake system. However, there is
one major differencethe aircraft brake system has two
master cylinders while the automobile system has only
An installation diagram of a typical independent-
type broke system is shown in figure 12-22. The system
is composed of a reservoir, two master cylinders, and
mechanical linkage, which connects each master
cylinder with its corresponding brake pedal, connecting
fluid lines, and a brake assembly in each main landing
Each master cylinder is actuated by toe pressure on
its related pedal The master cylinder builds up pressure
by the movement of a piston inside a sealed fluid-filled
cylinder. The resulting hydraulic pressure is transmitted