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FAQs of EWIS Service Life Extension Programs

Maintenance & Sustainment

Lack of information is often used to prevent actions from being taken. Assessment of all available options can seem stifling to find the path that provides the best value and the best means forward. This is as true about aircraft wire system sustainment as with anything else in life.

Key Takeaways
  • EWIS assessment supports maintenance programs to save time and money.
  • Predictive analysis of EWIS failures can help to organizations preemptively address EWIS issues.
  • The process is based on the best industry guidance and years of research.

Over the last 20 years, Lectromec has accumulated a set of frequently asked questions related to wire system sustainment. Here, we cover several high level questions about the assessment and its value and the subsequent article we will delve into some of the more technical details.

As you review this article, please keep in mind that we have a comment section below and we are happy to build upon your questions about the wire system sustainment.

Q: What is EWIS Assessment?

Performed on aircraft or fleets 20 years or older, the EWIS assessment is an established and vetted process to identify an aircraft’s electrical system health and predicts future performance in system reliability.

Q: How Much Can I Expect to Save on Maintenance?

Depends on the age, condition, and size of the fleet. There are two parts to cost savings when considering the wiring system assessment: improved performance and reduction/elimination of wire harness replacement.

Aircraft EWIS problems are often the last to be evaluated during maintenance actions. Numerous studies have found that EWIS problems are regularly underreported and are among the largest contributors to maintenance actions. By identifying the problems with the EWIS and implementing a plan of action, a significant improvement in aircraft reliability can be realized. Because the cost of unavailable aircraft varies from client to client, it is difficult to place a cost savings figure.

The second consideration for cost savings is regarding wire harness replacement. Frequently, maintainers are encouraged to replace all of the aircraft wiring because it is too old. Lectromec has never found an aircraft where full wire system replacement was necessary. When considering the downtime of the aircraft, wire harness replacement costs, engineering time, and shakedown of new hardware, wire system assessment provides a huge cost savings.

Q: What are the expected benefits from doing this assessment?

The expected benefits include:

  • Increase wire system reliability,
  • Reduce the number of wire harnesses necessary for replacement,
  • Improve maintenance by directly focusing on areas of degradation,
  • Reduce circumstances of no-fault found, and
  • Reliable engineering assessment and plan of action for continued service of the aircraft.

Q: Is this Process Trusted and Verified?

The EWIS Service Life Extension Process (SLEP) is based on work and research that Lectromec started in the 1980s. Over the past three decades, this research was extended by further work Lectromec performed with the Federal Aviation Administration (FAA) and the US military. From this, a fully vetted data centric process was developed.

Today, this process has been incorporated into the US military’s requirements for service life extension programs (SLEP) of aircraft systems. Further, Lectromec has adapted and applied the EWIS SLEP process for dozens of clients, many of whom have used this process for reassessments when further extending their fleet’s service life.

Q: What is the Downtime of the Aircraft?

Often when Lectromec works with the client on EWIS SLEP projects, the work is performed with scheduled maintenance. As such, the aircraft servicing time impact is typically less than one day.

Q: Will the Results make Sense to my Engineers/Maintenance Team?

Yes. The results are provided in a fully detailed report with clear descriptions of the work performed, remaining reliable service life predictions, and easy to follow recommendations.

Q: Are there any ITAR restrictions?


Q: Once I have the results, What Should be Done?

There are four possible actions from the analysis:

  • No Action Necessary: The analysis found that the wiring system is in good health and no further actions are necessary to maintain a reliable wire system. The data provided will support any service life extension requirements.
  • Increase Maintenance Actions: The analysis finds that there is some level of degradation with the wiring in portions of the aircraft. As a result, recommendations are made to more regularly evaluate and examine the wiring system. Lectromec provides recommendations on type and frequency of these inspections. Standard maintenance procedures are updated, and additional guidance is provided to technicians supporting the aircraft.
  • Wire Harness Replacement: The analysis finds that sections of the aircraft have significant degradation. To restore aircraft wire system reliability, it is necessary to replace some of the wiring harnesses. Note: in 30 years of EWIS analysis, Lectromec has never found the case where the entire rewire of an aircraft was necessary.
  • Design Change: During the evaluation of the wiring system, it is identified that there are some sections which benefit from modification. Lectromec will provide recommendations on possible changes and work with the maintenance team to determine the best means of applying the changes.

Q: What is the First Step?

Contact Lectromec to setup an appointment. During the initial discussion, we will discuss the size and age of the aircraft under evaluation and your project goals. From there, Lectromec will build a proposal to address your aging aircraft wiring system needs.

Michael Traskos

Michael Traskos

President, Lectromec

Michael has been involved in wire degradation and failure assessments for more than a decade. He has worked on dozens of projects assessing the reliability and qualification of EWIS components. Michael is an FAA DER with a delegated authority covering EWIS certification and the chairman of the SAE AE-8A EWIS installation committee.