NAVAIR 01-1A-509-3
01 March 2005
TM 1-1500-344-23-3
TO 1-1-689-3
CHAPTER 9
PRESERVATION AND PACKAGING
9-1. PURPOSE. The materials, equipment, and
g. Whenever the corrosion protection system has
techniques described in this chapter are intended to
failed in service.
assist the avionic technician at the Intermediate
Maintenance Activity (IMA) in preserving, packaging,
9-2.4. WHAT TO PRESERVE. Preservatives should
handling, and shipping avionic equipment.
be used only where their application and maintenance
will not hamper circuit or component operation.
Components that do not require preservation are listed
9-2. PRESERVATIVES.
in paragraph 9-2.5. Most preservatives form a
9-2.1. GENERAL. Surfaces and components not
nonconductive film that acts to insulate two mating
n o r m a l l y conformal coated or painted need
surfaces. For example, preservative on a relay's mating
preservation. Cleanliness and elimination of moisture
contacts will degrade operation of the relay. Each
are keys to avoiding corrosion. Since it is impossible
piece of avionic equipment should be inspected. With
to guarantee a dry, moisture-free environment,
the assistance of the applicable service directives,
preservation of equipment is essential. In today's
areas requiring preservation should be noted and
avionic systems, miniaturization has resulted in
preserved on a scheduled basis. The following items
microminiature circuits no longer than a pencil eraser.
may require preservation on a scheduled basis:
The slightest amount of corrosion can cause a whole
system to fail. Preservation has become an essential
a. Hinges and door latches.
part of the repair and maintenance of avionic systems.
b. Electrical connectors and receptacles.
9-2.2. WHY PRESERVE.
c. Shock mounts, rigid mounts, and associated
a. To protect nonmoving parts by filling air spaces,
brackets.
displacing water, and providing coatings.
d. Any dissimilar metals not otherwise preserved.
b. To protect components such as hinges, control
e. Antenna mounts, brackets, hardware, and
providing lubrication.
housings.
c. To protect nonoperating or idle equipment.
f. Fasteners, screws, nuts, and bolts.
9-2.3. WHEN TO PRESERVE. Preservatives should
g. Terminal boards, bus bars, and junction boxes.
always be used:
h. Equipment lids on the interior or exterior of
a. After avionic cleaning.
equipment that are susceptible to moisture.
b. On avionic equipment prior to shipment.
i. Solder joints not otherwise conformal coated.
c. O n equipment or components that are
j. Unpainted mounting brackets, equipment racks,
nonoperating or idle (including those awaiting parts).
and shelving.
d. Whenever access is achieved to parts normally
k. Unpainted equipment covers, lids, and chassis.
inaccessible for inspection without disassembly and
inspection.
l. External and internal surfaces of coaxial
connectors.
e. Whenever paint films in difficult-to-protect areas
require additional preservation.
m. External surfaces of cooling system joints.
f. After immersion or exposure to fresh water, salt
n. Grounding straps and wires.
water, or fire extinguishing agents.
