MIL-W-25038. MIL-W-25038 is a high-
WIRE REPLACEMENT
temperature, fire-resistant electrical wire. This
wire is made of nickel-clad copper with insulation
Before you can replace wiring, you need to
t h a t will operate efficiently in ambient
find information about the wire. First, consult the
temperatures that exceed +500F. Its insulation
aircraft's maintenance instructions manual (MIM)
design assures emergency operation of electrical
for wire replacement since it normally lists the wire
circuits subject to fires.
used in a given aircraft. When you cannot get this
information from the manual, you must select the
MIL-W-81044. MIL-W-8 1044 is a single con-
correct size and type of wire needed. The factors
ductor with tin, silver, and nickel-coated copper
in determining correct wire size are in NEETS,
or copper alloy wires insulated with various poly
module 4, and Installation Practices Aircraft
materials. You may use these poly materials alone
E l e c t r i c and Electronic Wiring, NAVAIR
or in combinations, depending upon application
01-1A-505. The procedures specified in NAVAIR
and part number.
01-1A-505 are mandatory for the maintenance of
naval aircraft. The information in these publi-
MIL-W-81381. MIL-W-81381 is a polyamide-
cations and in the latest Military Specification
insulated, single wire with silver and nickel-coated
MIL-W-5088 should help you select the correct
conductors made of copper and copper alloys.
replacement wire.
You may use polyamide insulation alone or in
The data necessary to determine the correct
combinations with other insulating materials,
wire for a given application is summarized below:
depending on application and part number.
1. Current drawn by the load (table 2-1)
MIL-C-7078. MIL-C-7078 includes three
2. Length of wire required to go from the
types of electrical cable.
source to the load
3. Allowable voltage drop between the source
1. Unshield/unjacketed/twisted--two or
or point of voltage regulation and the load
more coded wires with no overall jacket or
4. The maximum voltage that is applied to the
wire
shield
5. The approximate ambient air temperature
2. Jacketed/twisted--two or more coded
of the wire installation location
wires with no overall shield enclosed within
6. Whether the conductor is a stranded wire
a single jacket
in free air or one of a group of wires in a
3. Shielded/jacketed/twisted--one or more
bundle or in a conduit
coded wires, twisted, with an overall shield
enclosed within a single jacket
Wire Selection and Characteristics
MIL-C-27500. MIL-C-27500 is electrical cable
made up of two to seven-wire specifications.
After you have determined the wire size,
Cables of this type are included in the following
consider insulation characteristics. The following
groups:
are descriptions of the various military specifi-
cations of wires and cables. These military
1 . Unshielded/unjacketed--color-coded
specification numbers are on the reel, spool, or
wires, spirally laid without an overall jacket
shipping container. Always refer to NAVAIR
2. Jacketed--color-coded wires, spirally laid
01-1A-505 before selecting wires and cables for
with an overall jacket
weight discrepancies.
3. Shielded/jacketed--one to seven color-
coded wires, spirally laid with one or two
MIL-W-22759. MIL-W-22759 is a fluoro-
shields within an overall jacket
polymer-insulated single conductor electric wire.
It is made of tin-coated, silver-coated, or nickel-
coated wires of copper or copper alloy. You may
Aluminum Wire Properties
use this specification wire in combination with
other insulating materials. Temperature and
The use of aluminum wire in aircraft is well
voltage ratings range from 302F to 500F and
established. Therefore, you need to know some
600 to 1,000 volts, respectively, depending on part
of the unusual properties of aluminum.
number and application.
