l One or more insulated conductors covered with
a metallic braided shield (shielded cable)
. A single insulated conductor with a metallic
braided outer conductor (RF cable)
For wire replacement work, the aircraft
maintenance instruction manual (MIM) should be
consulted first. The manual normally lists the wire
used in a given aircraft.
CONNECTORS
Connectors are devices attached to the ends of
cables and sets of wires to make them easier to
connect and disconnect. Each connector consists of a
plug assembly and a receptacle assembly. The two
assemblies are coupled by means of a coupling nut.
Each consists of an aluminum shell containing an
insulating insert that holds the current-carrying
contacts. The plug is usually attached to the cable
end, and is the part of the connector on which the
coupling nut is mounted. The receptacle is the half of
the connector to which the plug is connected. It is
usually mounted on a part of the equipment. One type
of connector commonly used in aircraft electrical
systems is shown in figure 2-53.
TERMINALS
Since most aircraft wires are stranded, it is
necessary to use terminal lugs to hold the strands
together. This allows a means of fastening the wires
Figure 2-53.—Connector assembly.
to terminal studs. The terminals used in electrical
wiring are either of the soldered or crimped type.
Terminals used in repair work must be of the size and
type specified in the applicable maintenance
instruction manual. The crimped-type terminals are
generally recommended for use on naval aircraft.
Soldered-type terminals are usually used in
emergencies only.
The basic types of solderless terminals are shown
in figure 2-54. They are the straight, right angle, flag,
and splice types. There are variations of these types.
BONDING
An aircraft can become highly charged with static
electricity while in flight. If the aircraft is improperly
bonded, all metal parts do not have the same amount
of static charge.
A difference of potential exists
between the various metal surfaces. If the resistance
between insulated metal surfaces is great enough,
charges can accumulate. The potential difference
could become high enough to cause a spark. This
constitutes a fire hazard and also causes radio
interference.
If lighting strikes an aircraft, a good
conducting path for heavy current is necessary to
minimize severe arcing and sparks.
When you connect all the metal parts of an
aircraft to complete an electrical unit, it is called
Figure 2-54.—Basic types of solderless terminals.
2-43
