01 March 2005
d. Stray electrical currents can cause corrosion.
e. Active metals and dissimilar metals in contact
are often unprotected.
normal temperature changes during flight.
g. Avionic systems have many areas that trap
h. Hidden corrosion is difficult to detect in many
i. Many materials used in avionic systems are
subject to attack by bacteria and fungi.
j. Organic materials are often used that, when
overheated or improperly or incompletely cured, can
produce vapors. These vapors are corrosive to
electronic components and damaging to coatings and
3-2.1. GENERAL. Frequent corrosion inspections are
essential to the overall corrosion control program. By
early detection, identification, and treatment, the costs
resulting from corrosion are minimized. Without regular
systematic inspections, corrosion will seriously damage
avionic equipment. The following paragraphs describe
some of the basic aspects of visual inspection for
corrosion and the telltale signs associated with various
While in Storage
types of corrosion damage.
3-2.2. INSPECTION FACTORS. Calendar-based and
phase maintenance inspections shall be in accordance
with parent service or command directives. However,
extreme humidity, temperature, atmospheric conditions
d. Length of time aircraft is nonoperational.
and time shall be considered when determining the
frequency of corrosion inspections. The following
e. Nonpressurized equipment and equipment bays.
factors shall be considered when establishing local
f. Antenna and externally mounted avionic
packages such as electronic countermeasure (ECM)
a. Operational environment.
b. Known corrosion-prone areas such as battery
components, ram air turbines, and electrical bonds.
h. Equipment susceptible to particularly harsh
environments, such as sonobuoys and magnetic
anomaly detection (MAD) systems.
c. Length of storage time, with respect to equipment
and components. A corroded frequency test set is