Sourcing Aerospace Wire Harnesses and Cable Assemblies
To buy a flight or defense harness you can trust, name the workmanship standard, class and any space addendum, require genuine connectors and wire with traceability, and require recorded electrical test data and a first article report. Aerospace Sourcing matches harness jobs to qualified shops, flows those requirements down and checks the paperwork before shipment.
What wire harness sourcing covers
It covers any assembly of wire, cable, connectors and terminations built to your drawing: flight harnesses, cable assemblies, ground support equipment cables, test and checkout cables, and the harness segments inside boxes and racks. The build is only half the job. The other half is proving that the parts were genuine, the terminations meet a named workmanship standard and the finished assembly passed its electrical tests.
Typical requests include:
- Spacecraft and payload harnesses built to a space workmanship standard
- Launch vehicle and stage harnesses, including umbilical and pad interface cables
- GSE power, signal and data cables that connect test equipment to flight hardware
- Defense system cable assemblies built to prime contractor specifications
- Build-to-print replacements for legacy cables where the original source is gone
Harness work moves between design and manufacturing more than most build-to-print work. Decide early whether you are buying build to print from a complete drawing package or asking the shop to create build documentation from your schematic, because those are priced and scheduled differently.
Pick the workmanship standard and class first
Name the workmanship standard, its revision and the product class on the RFQ. IPC/WHMA-A-620, Requirements and Acceptance for Cable and Wire Harness Assemblies, is the industry consensus standard, and it sets acceptance criteria for crimped, mechanically secured and soldered interconnections and the tests that go with them.
Revision E was released in October 2022, and revision F was published in 2025 and replaces it. Contracts often stay on the revision that was current when they were signed, so cite the revision your program requires, not just the document number.
A-620 uses three product classes, and the customer assigns the class:
| Class | Intended products | Buyer notes |
|---|---|---|
| Class 1 | General products where function of the completed assembly is the main requirement | Rarely right for aerospace or defense hardware |
| Class 2 | Dedicated service products where extended life and continued performance are required, but uninterrupted service is not critical | Sometimes used for ground test and lab cables |
| Class 3 | High performance products where performance on demand is critical, downtime cannot be tolerated and the environment may be harsh | The normal starting point for flight, launch and defense hardware |
If you do not state a class, the shop has to guess, and its guess will not be Class 3 unless it has a reason. That single omission can make two quotes for the same harness incomparable.
Space hardware: the A-620 space addendum and NASA-STD-8739.4
For space hardware, call out the space and military addendum to IPC/WHMA-A-620 or NASA-STD-8739.4, depending on what your contract requires. Both add requirements beyond Class 3 for assemblies that must survive launch vibration and thermal cycling.
IPC/WHMA-A-620 space and military addendum. The revision E addendum, IPC/WHMA-A-620E-S, was released in November 2023. It supplements or replaces specific requirements of the base standard, applies only when procurement documents call for it, and cannot be used on its own. Pair the addendum revision with the base revision on your contract.
NASA-STD-8739.4. The NASA workmanship standard for crimping, interconnecting cables, harnesses and wiring is active at Version A, Change 4, and is mandatory for critical work as defined by NPD 8730.5. NASA has adopted the IPC/WHMA-A-620 space standard as an equivalent to NASA-STD-8739.4, and NASA's Office of Safety and Mission Assurance describes it as the preferred document for new NASA programs and projects.
NASA-STD-8739.6. NASA uses this standard to apply agency-wide workmanship requirements on top of the industry standards it adopts, including training requirements. If your hardware is for a NASA mission, read your mission assurance requirements to see which of these documents is imposed, and flow that exact set down.
Our pages on spacecraft and satellites and launch vehicles cover how these requirements show up across a program.
Soldered terminations: J-STD-001
If the harness includes soldered connections, such as solder cup contacts, splices or terminations on a small board, cite J-STD-001 for the soldering in addition to the harness standard. IPC aligned the soldering requirements in A-620 revision E with J-STD-001, but J-STD-001 remains the document that sets soldering process requirements, and many contracts cite both.
- J-STD-001 revision J, Requirements for Soldered Electrical and Electronic Assemblies, was released in March 2024.
- The space and military applications addendum, J-STD-001JS, was released in January 2025. Like the harness addendum, it modifies specific Class 3 requirements and is not used on its own.
When you buy a harness that terminates into a printed board assembly, make sure both standards are on the order and that the class matches across them.
Connectors and contacts
Specify connectors by full military or manufacturer part number, including shell finish, insert arrangement, polarization and contact type, and state whether substitutes are allowed. A connector called out loosely is one of the easiest ways for a harness to arrive with the wrong part.
MIL-DTL-38999 covers miniature, high density, environment resistant circular connectors with crimp removable contacts or hermetically sealed solderable contacts, and it is widely used on aerospace and defense harnesses. Its four series differ mainly by coupling:
| Series | Coupling | Typical reason to choose it |
|---|---|---|
| Series I | Bayonet, scoop proof | Blind mating and hard to reach locations |
| Series II | Bayonet, low profile | Weight and space limits |
| Series III | Threaded, self locking, scoop proof | High vibration and high temperature locations |
| Series IV | Breech, scoop proof, quarter turn | Blind mating with a short engagement rotation |
Shell finish classes matter for corrosion and outgassing, and hermetic classes are a different part entirely from environment resisting ones, so copy the full part number from the drawing rather than a description. Your drawing may call out other families, including rectangular and microminiature types. Whatever the family, ask the shop to buy connectors, contacts, backshells and tooling from the manufacturer or its authorized distributors, and to use the crimp tools and positioners the contact manufacturer specifies.
Wire and cable specifications
Call out wire and cable by specification and full part number, then require the shop to keep certificates and reel identification that tie each lot of wire to your harness serial numbers.
- SAE AS22759. Covers fluoropolymer insulated single conductor wire with tin, silver or nickel coated copper or copper alloy conductors, with construction set by the detail specification for each type. The base document was revised to AS22759E in July 2024. Cite the detail specification, gauge and color code your drawing requires.
- M27500 cable. Multi-conductor shielded and jacketed cable is still widely ordered by its M27500 designation, but MIL-DTL-27500 was cancelled and superseded by NEMA WC 27500. Check which document your drawing cites, and accept equivalent marking only if your engineering authority agrees.
On receipt, the shop should check that the wire print legend, reel label and certificate agree before the wire is cut. Our material certs and traceability page covers what a good certificate trail looks like, and receiving inspection covers how to check it at your dock.
Counterfeit rules for connectors and contacts
Treat connectors, contacts and any electronic components in the harness as counterfeit risk items, and flow down the DFARS clauses on defense work. A counterfeit or nonconforming contact can pass a continuity test and fail later in vibration.
DFARS 252.246-7007 (January 2023) requires covered contractors to run a counterfeit electronic part detection and avoidance system. Its criteria include training, inspection and testing, risk-based traceability from the original manufacturer to government acceptance, use of suppliers under 252.246-7008, reporting and quarantine of suspect parts, screening of GIDEP reports, control of obsolete parts and flowdown to subcontractors at all levels. The flowdown covers subcontracts for electronic parts or assemblies containing them, including commercial products.
DFARS 252.246-7008 (January 2023) sets the order of sources: the original manufacturer, authorized aftermarket manufacturer or their authorized suppliers first, contractor-approved suppliers next when parts are out of production and out of stock, and other sources only with prompt written notice to the contracting officer and contractor-run inspection, testing and authentication. The clause defines an electronic part as an integrated circuit, a discrete electronic component or a circuit assembly, so ask your contracts team how your program classifies connectors and contacts, and decide whether to apply the same rules to them regardless.
SAE AS5553, revision D from April 2022, is the industry standard for avoiding, detecting, mitigating and disposing of counterfeit EEE parts, and is meant to be flowed down to any organization that buys them. Our counterfeit parts avoidance guide goes deeper on the standards and test methods.
Electrical testing to require
Require electrical test of every finished harness to a stated test specification, with recorded results. A-620 includes test requirements and default levels that depend on class and construction, and your drawing or test specification can tighten them.
- Continuity. Confirms every conductor runs from the right pin to the right pin with resistance under the limit, and that there are no opens or miswires.
- Dielectric withstanding voltage (hipot). Applies a test voltage between conductors and between conductors and shields or shells to find insulation breakdown.
- Insulation resistance. Measures leakage between isolated conductors at a stated voltage to find degraded or contaminated insulation.
- Crimp pull testing. Destructive pull tests on sample crimps verify the tool, contact and wire combination. NASA-STD-8739.4 and A-620 both set minimum pull force values.
- Other tests your program may need. Shield termination resistance, time domain reflectometry or insertion loss on controlled impedance cables, and contact retention.
State the test voltage, dwell time, leakage or resistance limits and the test points, or reference the specification that contains them. Ask for test data by serial number, not a stamp that says tested. Environmental testing such as vibration or thermal vacuum is a separate lab job and should be requested separately if your program requires it.
Documentation: drawings, wire lists and first article
A harness shop builds from documents, so the RFQ package decides the quality of the quote. Send everything the shop needs to build and test without guessing.
- Harness drawing at a stated revision, with lengths, breakout locations, labels, sleeving and protective covering
- Wire list or from-to list giving each conductor's endpoints, wire specification, gauge and color
- Connector and parts list with full part numbers, approved alternates and backshell and strain relief details
- Schematic where the drawing does not show circuit function, so testing can be checked
- Test specification or test requirements on the drawing
- Marking and labeling requirements, including where serial and lot numbers go
Require an AS9102 first article inspection report on the first unit from a new source and after any change to drawing revision, process or location. Our first article inspection guide explains what the three AS9102 forms cover. If the harness is one part of a larger build, keep its FAI with the next higher assembly records.
Operator certification and ESD control
Ask who builds and who inspects your hardware, and what certifications they hold. The usual credential is an IPC certification to the A-620 endorsement: Certified IPC Specialist for operators and inspectors, and Certified IPC Trainer for the people who train them.
For NASA flight hardware, NASA-STD-8739.6 adds training requirements, including a hands-on practical exam that the standard IPC base course does not include. NASA's workmanship program has piloted a NASA credential for people who only inspect, separate from the IPC specialist certificate. If your contract imposes NASA workmanship training, flow that down specifically, because a shop with only commercial IPC certificates may not meet it.
Electrostatic discharge matters whenever the harness connects to sensitive electronics or includes components. ANSI/ESD S20.20, published by the ESD Association, defines the requirements for an ESD control program, including protected areas, handling, training, packaging and marking. NASA-HDBK-8739.21 gives guidance for building a program to it. Ask whether the shop runs a program to S20.20 and how finished assemblies are packaged.
What to put on the harness RFQ
These lines turn a harness drawing into a request that several shops can quote the same way:
- Drawing number and revision, wire list and parts list
- Quantity per lot, total program quantity and whether units are serialized
- Workmanship standard, revision and class, plus any space or military addendum
- Soldering standard and class if any soldered terminations exist
- Approved connector, contact and wire sources and whether alternates are allowed
- Counterfeit avoidance requirements and DFARS or prime contract clauses that apply
- Electrical test requirements and the data you want back
- First article requirement and any source inspection by you or your customer
- Operator training and certification requirements
- ESD, packaging and labeling requirements
- Need date and whether a first lot ahead of the rest helps
- Export control status of drawings and hardware
Harness drawings on defense and launch programs are often controlled technical data. Our confidentiality page explains how files are handled, and controlled data moves only through the controlled programs process, to US persons.
How Aerospace Sourcing handles a harness job
We match your harness to a shop that builds to the standard and class you need, flow down the requirements and check the paperwork before shipment. We do not run harness lines ourselves, and we do not promise that a shop is available for every job or schedule.
- One quote, one lead time, one point of contact and one purchase order, even when the harness, its connectors and any testing involve more than one source
- Workmanship, counterfeit avoidance, test and documentation requirements flowed down in writing
- Test data, FAI and certificates reviewed against the PO before shipment
- A certificate of conformance with every order, plus the other certificates your request requires
A person replies within one business day, and rush requests are prioritized. Every supplier signs a flow-down NDA before seeing files, and suppliers do not learn the end customer unless you approve. Our pages for satellite manufacturers and defense contractors cover how we support each. Our defense systems reference covers the program side.
Request a wire harness quote
Send the drawing package through the wire harness request form. It is preset for harnesses so it asks for the workmanship standard, class, addendum and test requirements up front, which are the details that decide which shops can quote and whether their prices are comparable. A person will reply within one business day.
Questions
Should a flight harness be built to Class 2 or Class 3?
Class 3 is the normal starting point for flight, launch and defense hardware, because it is the A-620 class for products where performance on demand is critical and the environment may be harsh. Space hardware usually adds the space and military addendum or NASA-STD-8739.4 on top. The customer assigns the class, so state it on the RFQ rather than leaving the shop to choose.
Is the IPC/WHMA-A-620 space addendum the same as NASA-STD-8739.4?
They are separate documents, but NASA adopted the A-620 space standard as an equivalent to NASA-STD-8739.4 and describes it as the preferred document for new NASA programs. NASA-STD-8739.4 remains active and mandatory where it is imposed. Your contract or mission assurance requirements decide which applies, so flow down exactly what your program cites, including the revision.
Do the DFARS counterfeit clauses apply to connectors?
DFARS 252.246-7008 defines an electronic part as an integrated circuit, a discrete electronic component or a circuit assembly, and 252.246-7007 flows down to subcontracts for electronic parts or assemblies containing them. How connectors and contacts are classified on your program is a question for your contracts team. You can require authorized sources and traceability for connectors and contacts either way.
What tests should every harness get?
At minimum, continuity to confirm correct pin-to-pin wiring and no opens, plus dielectric withstanding voltage and insulation resistance where the design and class call for them. A-620 sets default levels that depend on class and construction, and your drawing or test specification can tighten them. Ask for recorded results by serial number, and add crimp pull tests on samples to verify tooling.
Is M27500 cable still a valid callout?
The designation is still widely used, but MIL-DTL-27500 was cancelled and superseded by NEMA WC 27500. Many drawings still say M27500. Check which document your drawing cites, and if the shop proposes cable marked to the NEMA specification, get your engineering authority to confirm it is acceptable before the order is placed.
Can you source harnesses for GSE as well as flight hardware?
Yes. GSE cables are often built to a different class and test specification than flight harnesses, and they connect to flight hardware, so the interface connectors and test requirements still need care. Send the drawing and your requirements, and we match the job to a suitable shop. Our ground support equipment page covers the mechanical side of GSE.
Related
Sources
- IPC: IPC/WHMA-A-620 space and military addendum task group (7-31FS)
- ANSI Blog: IPC/WHMA-A-620F-2025 cable and wire harness assemblies
- IPC: release of IPC/WHMA-A-620E
- NASA Technical Standards: NASA-STD-8739.4 Version A Change 4
- NASA OSMA: IPC/WHMA-A-620 Space alternate training credentials for inspectors
- ANSI Webstore: IPC J-STD-001JS space and military addendum (2025)
- Glenair: MIL-DTL-38999 Series I, II, III and IV connectors
- SAE: AS22759 fluoropolymer insulated wire
- EverySpec: MIL-DTL-27500H cancelled, superseded by NEMA WC27500
- Acquisition.gov: DFARS 252.246-7007
- Acquisition.gov: DFARS 252.246-7008 Sources of Electronic Parts
- SAE: AS5553 Counterfeit Electronic Parts
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