Table 1 lists preventive maintenance checks, and service and replacement criteria for the UMARK components. A
pre-usage inspection is required on those kit items used whose Interval in column (3) is identified as before and
after. In addition to Table 1 requirements, the following also applies:
a. Prior to use of the UMARK, the kit is to be inspected for completeness.
A lock pin or quick-release pin frozen in the retracted
or unlocked position will result in catastrophic failure
of the associated component and loss of the recovered
helicopter. Check all lock pins and quick-release pins
for proper operation.
b. All lock pins and quick-release pins are to be inspected for freedom of movement and lubricated as necessary
to ensure proper operations.
If safety wire at pivot end of the sling link assemblys
spring lock is not present excess loads on the sling
links spring lock may cause the spring lock to open
resulting in separation of slings attached to the sling
link and possible loss of recovered helicopter.
c. At the sling link assembly, the safety wire securing the two sides of the spring lock pivot end must be secured
with MS20995C32 safety wire as seen in Figure 1. If the safety wire is missing, broken, or improperly installed
replace safety wire as follows:
Figure 1. Sling Link Assembly Safety Wiring of Spring Lock
(1) Using a 20 inch length of safety wire leave three inches of one end of the safety wire pointing away
from and along the center line of the sling link, loop the remaining end of the safety wire two times
around the left hand side wire (Point A) of the spring lock and tighten.
(2) Take the end of the safety wire just looped under the left hand side wire of the spring lock and loop it
twice around the middle two wires of the spring lock and loop twice around the middle two wires of
the spring lock (Point B) and tighten.