FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 11. Aircraft Electrical Systems | 17. Connectors | 11-232. Types of Connectors
9/27/01
SECTION 17. CONNECTORS
AC 43.13-1B CHG 1
11-230. GENERAL. There is a multitude
of types of connectors. Crimped contacts are
generally used. Some of the more common
are the round cannon type, the rectangular,
and the module blocks. Environmental-
resistant connectors should be used in appli-
cations subject to fluids, vibration, thermal,
mechanical shock, and/or corrosive elements.
When HIRF/Lightning protection is required,
special attention should be given to the termi-
nations of individual or overall shields. The
number and complexity of wiring systems
have resulted in an increased use of electrical
connectors. The proper choice and applica-
tion of connectors is a significant part of the
aircraft wiring system. Connectors must be
kept to a minimum, selected, and installed to
provide the maximum degree of safety and
reliability to the aircraft. For the installation
of any particular connector assembly, the
specification of the manufacturer or the ap-
propriate governing agency must be followed.
11-231. SELECTION. . Connectors
should be selected to provide the maximum
degree of safety and reliability considering
electrical and environmental requirements.
Consider the size, weight, tooling, logistic,
maintenance support, and compatibility with
standardization programs. For ease of assem-
bly and maintenance, connectors using
crimped contacts are generally chosen for all
applications except those requiring an her-
metic seal. (Reference SAE ARP 1308, Pre-
ferred Electrical Connectors For Aerospace
Vehicles and Associated Equipment.) A re-
placement connector of the same basic type
and design as the connector it replaces should
be used. With a crimp type connector for any
electrical connection, the proper insertion, or
extraction tool must be used to install or re-
move wires from such a connector. Refer to
manufacturer or aircraft instruction manual.
After the connector is disconnected, inspect it
for loose soldered connections to prevent un-
intentional grounding. Connectors that are
susceptible to corrosion difficulties may be
treated with a chemically inert waterproof
jelly.
11-232. TYPES OF CONNECTORS.
Connectors must be identified by an original
identification number derived from MIL
Specification (MS) or OAM specification.
Figure 11-35 provides some examples of MS
connector types. Several different types are
shown in figures 11-36 and 11-37.
a. Environmental Classes. Environ-
ment-resistant connectors are used in applica-
tions where they will probably be subjected to
fluids, vibration, thermal, mechanical shock,
corrosive elements, etc. Firewall class con-
nectors incorporating these same features
should, in addition, be able to prevent the
penetration of the fire through the aircraft
firewall connector opening and continue to
function without failure for a specified period
of time when exposed to fire. Hermetic con-
nectors provide a pressure seal for maintain-
ing pressurized areas. When EMI/RFI pro-
tection is required, special attention should be
given to the termination of individual and
overall shields. Backshell adapters designed
for shield termination, connectors with con-
ductive finishes, and EMI grounding fingers
are available for this purpose.
b. Rectangular Connectors. The rec-
tangular connectors are typically used in ap-
plications where a very large number of cir-
cuits are accommodated in a single mated
pair. They are available with a great variety
of contacts, which can include a mix of stan-
dard, coaxial, and large power types. Cou-
pling is accomplished by various means.
Smaller types are secured with screws which
hold their flanges together. Larger ones have
integral guide pins that ensure correct align-
ment, or jackscrews that both align and lock
Par 11-230
Page 11-91