Routing list: How Does It Work in Aircraft Manufacturing

Routing List (RL) has been used since 1958, soon after the air crash due to faulty device installation. Like any other system, it plays an important role. It provides a wide range of information for the technician, removing any guesswork and safely accomplishes tasks, i.e., assembling and manufacturing.
Now, it is necessary from the Federal Aviation Administration (FAA) for all aircraft manufacturers to devise in-depth wire harness tables for each application.

What is a Routing List for an Aircraft?

Generally speaking, every plane has a specific routing list based on the design and the electrical components. In other words, it refers to the wire attachment pattern in the wire harness. For example, wire XAT-125-21 may go from reference designate P1220 to reference designate T5321. Thus it is ‘routed’ from P1220 to T5321. 

This process helps the engineers and the technician to get the record of a single wire.  Furthermore, they can use it as a guide when doing regular maintenance.

Information in the Routing List

As mentioned above, a routing list generally gives detailed information about the wire harness in the plane. Some of the significant features are:

Wire length

By checking the respective devices connecting wires, you can measure the wire length with the help of color codes on the wire.

Wire gauge

Wire gauge measurement can help you assemble at tight locations where limited space is available, but you have to use more than one different purpose. Thus, having the gauge approximation can help in visualizing the necessities.

Contact cavity

The routing list also gives you information on wire contact gravity. So it is helpful when you need some reference designator.

Wire Termination

You get the information of wire termination where the contact part gets a certain number. Thus, it is helpful for easier identification afterward.

Wire part number

Each wire part makes up a special and unique number which does help quite a lot in differentiating between wire Amps requirements for each device.

System number of wire

Since we use the wire harness subjectively, we number systems through following good design and assembly practices.

Type of signal

The table also provides helpful information about the type of signal that a wire is possessing/carrying. Due to the electromagnetic effect, wiring of the same polarity may be distortion and noise, disturbing the signs at the output. Hence, knowing the type of signal the wire is caring for, you can take preventive measures beforehand.

Other Names of the Routing List

Routing list also has other names like pin-out list, termination list, wire list, etc. But no matter what you call it, you can always use it to make your working process easier and more efficient.


Besides wire numbers and the reference indicators, you can get much more information from the tables.  With it, you have a record of iteration. 

It is worth noting that the RL list varies across different plane makers like Rockwell Collins, Boeing, Dassault Systems, and Lockheed Martin, etc. The configuration and the design consideration also differ across manufacturers. If something is confusing you, contact us

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