Aircraft Coax General Repair & Design Guidance

[kontiki99]

All,

It seems like more and more, every repair we do on an aircraft coaxial cable ties us to a specific vendor P/N for the installation. I'm looking for guidance that will allow me to identify equivalent components and make substitutions. There are usually not that many variables to account for, I just don't know which specifications I should be looking at. Anybody know of a good GP guide and which specifications are the accepted standard?

I have run across coax applications where the cable in use had inert gas sealed inside and we simply did not have the equipment, but most aircraft applications are simply not that exotic.

Thanks,

My posts reflect my personal views and are not in any way endorsed or approved by any organization I'm professionally affiliated with.

 

[VEBill]

As you almost certainly already know, there would be a formal Airworthiness process to go through before substituting parts. That said...

At one end, the RF connector interfaces to the coaxial cable. That's obviously a key parameter.

At the other end, the RF connector interfaces with the mating receptacle. The type of connector (e.g. N, TNC, BNC) is obvious.

In between you need to be aware of the required qualifications (specs, standards), materials (e.g. forbidden plastics, metals), required metals and finishes, required markings, RF parameters (frequency and loss), assembly method (soldering, crimp, clamping assembly).

The assembly (maintenance) instructions may vary for different connector PNs, even if they're basically equivalent. So using several PNs can impact the manuals.

Beware of making Alternate PNs generally. Better to do so on a given Parts List instance basis. Unless the parts are essentially identical.

 

[WKTaylor]

IF you can find a copy...

T.O. 1-1A-14 or NAVAIR 01-1A-505-1 or TM 1-1500-323-24-1
INSTALLATION AND REPAIR PRACTICES - VOLUME 1 - AIRCRAFT ELECTRIC AND ELECTRONIC WIRING

Regards, Wil Taylor

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