When a wire gets damaged or cut in an aircraft often we can repair it by means of a splice.
There are different areas in the aircraft that need different types of splices to be installed.
Inside of the pressure cabin in dry places we can use non-moisture proof splices wich are crimped with a non-moisture proof crimptool or if that is not available a terminal crimp tool.
If a wire needs to be repaired in a wet area or outside of the pressure cabin we use moisture proof splices wich require this moistureproof splice tool.
The military spec number for this tool is M22520/37-01. We have a couple of these tools from Raychem, the AD-1377.
U could also use another toolmanufacturer tool with the same military specification, the GMT232 from CMS (Connector Microtooling Systems) or the 3137CT from Sargent tools wich is a replica of the AD-1377.
A moisture proof splice is a metal barrel and a plastic sleeve wich needs to be heated for the ’glue’ to liquify on both sides to seal up the sleeve. This type of splice where two wires are connected to each other head on is called a ’butt-splice’ or a ’inline-splice’.
We use three sizes, the smallest ones being the red’s, then the blue’s and the biggest ones being the yellow’s.
The partnumbers are:
red: D-436-36 (tin plated)
red: D-436-82 (nickel plated)
blue: D-436-37 (tin plated)
blue: D-436-83 (nickel plated)
yellow: D-436-38 (tin plated)
yellow: D-436-84 (nickel plated)
These splices are also available with 3 entry holes in the shrink sleeve for a maximum of 6 wires on one side (two per hole) and 2 in the (single) hole on the other side.
red: D-436-0110 (tin plated)
red: D-436-85 (nickel plated)
blue: D-426-52 (tin plated)
blue: D-436-86 (nickel plated)
yellow: D-436-53 (tin plated)
yellow: D-436-87 (nickel plated)
Then there are also splices available with sleeves that can hold 6 wires on each side (2 per hole).
red: D-436-0115 (tin plated)
red: D-436-88 (nickel plated)
blue: D-436-42 (tin plated)
blue: D-436-89 (nickel plated)
yellow: D-436-43 (tin plated)
yellow: D-436-90 (nickel plated
Another way of splicing (or endcapping) is by means of a ’stub splice’ or a ’parallel splice’.
red: D-436-0128 (tin plated)
red: D-436-0119 (nickel plated)
blue: D-436-58 (tin plated)
blue: D-436-75 (nickel plated)
yellow: D-436-59 (tin plated)
yellow: D-436-76 (nickel plated)
It’s possible to get these parallel splices with more openings in the shrinksleeve. These next ones have 5 holes to feed a maximum of 10 wires (2 per hole).
Don’t let the pictures fool u, these sleeves have 5 holes.
blue: D-436-60 (tin plated)
blue: D-436-77 (nickel plated)
yellow: D-436-61 (tin plated)
yellow: D-436-78 (nickel plated)
If u only want the crimp barrel, here are the partnumbers.
red inline: D-609-06 (tin plated)
red inline: D-609-09 (nickel plated)
blue inline: D-609-07 (tin plated)
blue inline: D-609-10 (nickel plated)
yellow inline: D-609-08 (tin plated)
yellow inline: D-609-11 (nickel plated)
red parallel: D-609-03 (tin plated)
red parallel: D-609-12 (nickel plated)
blue parallel: D-609-04 (tin plated)
blue parallel: D-609-13 (nickel plated)
yellow parallel: D-609-05 (tin plated)
yellow parallel: D-609-14 (nickel plated)
And if u only want the crimp sleeve, here are the partnumbers (only the regular crimpsleeve with one hole on each end can be ordered loose).
red: D-436-0096
blue: D-436-0097
yellow: D-436-0098
First the wires that need to be connected obviously need to be stripped to expose the conductor, it is best to put the sleeves over the wires at this stage because it would not be the first time somebody crimped the splices on the wires to find that he or she forgot the moisture proof sleeves and had to start over.
Then the wires that need to be connected obviously need to be stripped to expose the conductor, then the barrel is put over one of the wires and crimped onto that wire using the moistureproof splice tool.
Then the other wire is inserted into the other end of the barrel and then that side of the barrel is crimped.
Then the sleeves can be put over the splices and we heat them with a heat gun until the ’glue’ has liquified and starts to come out of the sleeve.
At this time the splice should still be transparent for inspection and show no sign of overheating.
Here’s a look at a red size moistureproof splice, note that u can still see the splice inside the sleeve and that the sleeve is completely shrunk over the splice and the wire.
We can also use the moistureproof splice tool for endcapping wires.
Endcapping wires is simply to take a installed wire and make sure that the conductor can not contact anything.
There are several ways of endcapping a wire, for this tool we use the endcap splice.
We put it over the conductor of a wire and crimp it with the moistureproof splice tool.
For this type of endcap we use a endcap sleeve, this will seal the splice at both ends making sure that no moisture can reach the conductor.
We heat the endcap sleeve, liquifying the ’glue’ and sealing the endcap.
And once again, the sleeve must remain transparent and the endcap must be completely moistureproof. This type of splice is called a ’parallel-splice’