description of when and how to perform the job, even
down to what tools, parts, materials, and test equipment
will be needed. The MRC is a situation requirement
card, which means replacement of the cables is
accomplished when certain adverse conditions are met,
such as maximum allowable service life of the cables,
maximum number of shots allowed, or reaching the
maximum number of broken wires allowed before
replacement becomes necessary.
Inspection Criteria: The cables are locally sub-
jected to severe atmospheric conditions produced by
heat and steam, which are destructive to the life of the
cables. Inspection of the cables must be performed
periodically (when scheduled by PMS) for visual
damage, such as broken wires, rust, excessive wear,
kinks, and dirt. Damage to the cables may be internal
as well as external. A wire broken internally may be
seen externally as such a wire will eventually work its
way to the outside surface. In addition to checking for
visual damage to the cables, a record of the number of
shots and the length of service must be kept for each
set of cables. Any of the following conditions is cause
for replacement of the retrieving or towing cables:
Five or more broken wires in one rope lay. The
length of wire rope in which one strand makes one
complete revolution about the core is one rope lay.
Twenty or more broken wires in any 30-foot
length. The length of service and the number of shots
allowed on the cables vary with the type of cables in
For cables with a steel core, 3,500 to 4,000
shots or 24 months in service, whichever comes first.
Replacement of the cables (advance or retract) must
be made in pairs and each set must be of the same wire
rope construction. This prevents uneven stretch of a pair
Catapult Work (Rough) Logbook
A catapult work (rough) logbook may be
maintained for each catapult in service, containing all
pertinent information acquired daily on the operation,
maintenance, testing, and repair of a
catapult. Logbooks may be requisitioned from General
Services Administration (GSA) stores under National
Stock Number 7530-222-3525. Log entries may include
1. Lubrication oil usage rate (gallons per hundred
shots) and lubrication schedules completed.
2. Malfunctions (such as hangfires, slow or
runaway shots, premature grab release, failure of dome
accompanying the malfunction.
3. Date, time, and type of inspection conducted,
any unusual condition disclosed by the inspection,
number of shots on component part and catapult system
at the time of the inspection, and special information
such as clearance dimensions.
4. All test and maintenance conducted on compo-
nents, or any tests pertinent to catapult machinery.
5. All repairs, replacements, or failures of
components, along with a full explanation of the
corrective action taken. Background history of any
previous failures may be included.
6. Service changes that have been incorporated,
whether in whole or in part.
To maintain continuity, logbook entries should be
made each day. If launching, inspections, maintenance,
or repairs are not conducted during a 24-hour period, a
brief log entry may be made including the status of
catapult (READY, STANDBY, or SHUTDOWN), the
reason for the catapult being nonoperational, and other
pertinent information as directed by the catapult officer.
A rough catapult logbook that has been completely
filled with entries should be kept for a period of 2
years. Books more than 2 years old should be
In this chapter we have described functions and
operations of the major catapult systems, descriptions of
charging panels and control consoles, and general
maintenance procedures. For a more detailed study of
the catapult systems and components, see the applicable
NAVAIR technical manual with the latest revisions.