We hope you had a wonderful Thanksgiving holiday! As we enter the last days of 2021, we’d like to highlight one of our top blogs from 2018 that covers a very important topic in the aerospace wiring industry: what is a wiring harness manufacturing specification?
For each new aircraft platform (a platform is an aircraft designation such as an F-15, F-16, F-35, KC-46, P-8, 787, etc.) that is designed and produced by the Original Equipment Manufacturer (OEM), such as Lockheed Martin or L3 Harris, there are many manufacturing specifications for their aircraft. A few example specifications are: (1) landing gear system, (2) fuel system, and (3) lighting system. Many people do not think of it as a system, but another one is the wiring system, more commonly called the Electrical Wiring Interconnect System (EWIS). EWIS is the complete aircraft wiring system and associated components such as wire, connectors, backshells, bundle clamps, wire splices, etc. EWIS includes bundles of wires that are commonly called wiring harnesses.
So, what is a wiring harness manufacturing specification? That’s a good question. The short answer is a wiring harness manufacturing specification is the engineering document that provides details (i.e. specifications and processes) on how to assemble wiring harnesses for a given aircraft. Most wiring harness manufacturing specifications are fairly large documents (many over 50 pages long). Some of the information includes: (1) how shields from shielded wires are attached to other devices such as connectors, backshells, terminals (this is commonly called shield terminations), (2) whether to install spare contacts and filler plugs into empty contact cavities, (3) how much to torque backshells to connectors, (4) how to clock connectors to right angle backshells, (5) how to cover a wiring harness with braid, shrink tubing, or string tie, and (6) how to test wiring harnesses after they are assembled.
InterConnect has manufactured our products to many different wiring harness manufacturing specifications over the years. The aircraft platform that InterConnect has specialized in assembling wiring harnesses for the longest is the F-16. InterConnect has made over 10,000 different part numbers for the F-16. For each part number, InterConnect has used Lockheed Martin’s wiring harness manufacturing specification called 16PR145. Although 16PR145 started-out as a fairly small document, it is now over 600 pages long. It is up to InterConnect to know and understand everything called out in 16PR145.
Some OEMs decide not to write a wiring harness manufacturing specification. Instead they ask InterConnect to write one for them. InterConnect has written many wiring harness manufacturing specifications over the years based on customer requests. InterConnect bases our specifications on best practices, lessons learned, and essentials to the aircraft platform.
If you work for a company that does not have its own wiring harness manufacturing specification and desires to use one common throughout the aircraft industry, InterConnect recommends the following standards as noted in our blog “What is SAE-AS50881 and how does it relate to wiring harness design?”:
- IPC/WHMA-A-620: Requirements and Acceptance for Cable and Wire Harness Assemblies
- IPC-A-610: Acceptability of Electronic Assemblies
- IPC J-STD-001: Requirements for Soldered Electrical and Electronic Assemblies
- NAVAIR 01-1A-505-1: Harness Installation and Repair Practices for Aircraft Electric and Electronic Wiring. This standard is a combination of the former US Navy standard with the same name as well as the former US Air Force Standard T.O. 01-1A-14 and former US Army standard TM 1-1500-323-24-1.
If you have questions or comments about wiring harness manufacturing specifications or would like InterConnect to create one applicable to your aircraft platform, please let us know or call +1-817-377-9473.