Harness manufacturers face a number of trials when faced with their daily projects, but few provide the unique challenges required for assembling or repairing wire harnesses made for aerospace applications.
Successful aerospace harnesses are typically:
- Large and heavy
- Complex, usually containing hundreds of components and multiple breakouts
- Able to withstand extreme environmental and operating conditions
And it goes without saying that they need to be absolutely reliable.
Manufacturers not only need qualified, diligent, and dedicated employees, they need to use the proper tools, be aware of the latest technologies, and be compliant with the most current standards and requirements.
A New Challenge
Twenty years ago, aircraft manufacturers would typically disassemble and repair most of their components in-house. This included wire harnesses. However, after 9/11, and a downswing in the airline economy, most aircraft manufacturers outsource harness creation, repairs, testing, and rebuilding.
This creates unique challenges for the harness manufacturer in that they need to repair a harness they didn’t create. They are reliant on the documentation provided by a different assembler.
Another consideration is that the original manufacturer may not allow outsourcing repairs by another vendor but will allow other costly requirements such as “check and test.” For this process, the original harness manufactures are required to create designed engineering representative (DER) repairs, which will determine if the harness is even repairable, and – if so – they develop a component maintenance manual on how to perform the repairs. This previously time-consuming process has been widely adopted, so many harness manufacturers have templated the process in order to deliver a DER within a month and have learned to work with the companies who may do the repair and install the harness while restoring the rest of the engine.
Manual Labor is a Must
Despite all the industry changes and advances in technology, harness assembly – specifically in the aerospace realm – remains a manual assembly process.
Harness assemblers typically go through a two-month training program to learn the practices of the company where he or she is assembling – but then will receive additional training for the specific requirements of the customer.
Harnesses can come from all over the world and each variation has its own requirements for assembly and installation so many assemblers cross train to become familiar with the assembly process for each type. Additionally, assemblers may receive training in how to perform soldering and be certified to the IPC J-STD-001C standard.
Aerospace harnesses are also often difficult to test and remove so assemblers are trained with portable computerized test equipment. These testers can connect easily to the engine or fan case harness, provide quick and accurate test results, and ensure the harness meets the manufacturer’s component maintenance manual requirements. More importantly, this means of testing often eliminates unnecessary harness replacements – saving labor costs and aircraft downtime.
An Ever-Advancing Industry
As airplane electrical systems become increasingly complex, featuring many more connections, and as wiring system regulations evolve, the harnesses created must keep up.
Consider some of the largest, heaviest and most complex harnesses created to date:
Sam Symonds, president and CEO of CIA&D recalls, “The harness was 40 feet long and had 60 branches, 35 of which fed from one breakout point. All the branches were braided with electromagnetic shielding and anti-chafing braid material. We had 8 technicians spend 340 man-hours on the harness.”
“Our longest harnesses have been more than 100 feet and were used in the fuselage of planes made by several companies,” says Evert Rubingh, senior sales and marketing manager for Fokker Elmo The Netherlands. “The most complex harnesses we’ve made each contained more than 6,000 connection points. They were installed in the airplane cockpit or avionics bay, which is located under the flight deck and houses the plane’s electronic modules. Testing a harness with 6,000 connectors can take more than 24 hours.
Additionally, one of the most unique harness challenges Fokker Elmo workers ever faced was for a commercial airline. Assemblers had to build a 3D harness board that allowed them to run the wires and form the bundle in the exact shape it would be installed on the airplane.
Solution for Wiring Harness Cable Assembly Needs
Don’t hesitate to contact ACDi for Wire Harness Cable assembly support. For over 30 years ACDI has specialized in the manufacture of a wide variety of wiring harnesses, cable assemblies, and chassis units for commercial, industrial, military, and medical applications. ACDi is certified and listed by UL as a “Wiring Harnesses – Component” manufacturer.
ACDI offers specialized testing services as part of our overall agility to provide a complete package for harness and cabling solutions. We perform 100 percent in-house wire harness/cable testing incorporating Cirrus Harness Test Systems with customized interface tooling as required. Testing solutions are designed to verify continuity, opens, shorts, insulation resistance, passive components and hi-pot testing to ensure compliance with customer specifications.
ACDI’s Quality Management System (QMS) is AS9100 / ISO 9001 certified and ACDi provides in-house training and certification to meet IPC 610, J-STD-001 and IPC/WHMA-A-620 workmanship standards. All wire harness and cable products are subject to 100 percent inspection, test, and verification to ensure compliance with customer specifications prior to shipment.