By Jim Jenkins
Aging Aircraft Public Affairs

Myth has it that aircraft wiring is not a maintenance issue.

Detailed research on Maintenance Action Forms coupled with fleet surveys paints a much different picture. In-depth analysis revealed that aircraft wiring failures are significantly under reported and that wiring failures are indeed a concern for the fleet.

One major reason wiring failures are underreported is that maintenance personnel were over-using malfunction code 160, which has a very generic description of why the wire has failed. It was sort of a one size-fits-all mentality.

Research also revealed that many components described as having a Mal Code of 799 -- a failure that cannot be duplicated – were actually experiencing wiring failures, but not necessarily related to the component. The wiring failure simply affected the component causing maintainers to believe it was a component that failed. These components were usually swapped out for another component, which may have worked until the initial failure reoccurred, causing a series of “swaptronic” events to happen. The actual wire failure was never traced, so very expensive components were swapped back and forth, going in and out of intermediate level shops receiving maintenance they didn’t need. A lot of money and maintenance man-hours were wasted.

In order to better define wiring failures, Mal Code 160 was removed from the Naval Aviation Maintenance Program and 63 new “Wiring” Malfunction Codes were added.

“But, in our attempt to accurately capture wiring failures, did we go too far?” said Harry Proffitt, Assistant Program Manager for Logistics with the AAIPT. “We may have been a little too zealous in our efforts.”

The 63 new wiring malfunction codes were designed to neck down how failures on wiring are occurring. This is a great tool for analysts, but, what about the fleet maintainer? Does the fleet know about these codes? Does the fleet accurately use these codes? Are there too many or too few codes?

“These are the questions we need to have answered,” Proffitt said.

This is a great opportunity for the fleet to get directly involved and we need their help. Aircraft maintainers (mostly AEs, ATs, AOs, QDRs & CDIs) are needed to provide assistance in accurately identifying and documenting specific aircraft wiring failures and identifying the necessary Mal Codes for capturing those failures. The AAIPT is trying to get the word out there that new wiring malfunction codes have been released with the OPNAVINST/COMNAVAIRFORINST 4790.2 since March 2005. These expanded wiring malfunction code descriptions are now organized by failure categories and groups so that maintainers can better identify the specific wiring failures.

If we continue to inaccurately report wiring failures, then wiring will never receive the needed attention from the naval aviation maintenance community.

Maintainers, analysts, and engineers need to understand the root causes of the wire failures, said Bob Ernst, AAIPT director. Sensors are collecting lots of data, but the data doesn’t point to root causes of failures. Previously, there were only six malfunction codes available to maintainers to report. Engineers didn’t know how to help the maintainers because the problems they were reporting did not provide a root cause.

To assist the aircraft program offices and analysts who review, monitor, analyze, and study the Naval aviation maintenance data, the 63 new aircraft wiring malfunction codes were developed specifically to identify the root causes of wire failures.

“We need to find out if the wire is chafed, if it’s misrouted, if it’s a bad solder joint, crimp or whatever,” Ernst said. “We need to understand, not only what the problem is, but what [part of the aircraft] it is in, also.”

With the new malfunction codes, engineers will be able to identify what the failure is and map the right solution to solve the problem.

“These new “W” aircraft wiring malfunction codes are designed for more accurate aircraft wiring failure data collection so that the Navy’s decision makers have a better understanding of the actual degradation conditions of the Navy’s aging aircraft wiring problems,” said Andy Yang, of the Wiring Systems Branch, Propulsion and Power Department. “Then these decision makers can allocate the resources and funding to implement the much needed solutions to fix these aircraft wiring problems.”
To provide feedback please e-mail Yang at [email protected].

(Harry Proffitt and Andy Yang contributed to this article)