Jetrader - September/October 2011 - 39

In the past few years, economic considerations have driven many aircraft to be operated long beyond their planned retirement. When you look at aircraft that are experiencing extended service life such as the Douglas DC8, 9, and 10; Boeing 727,737, and 747; or the Airbus A310, you realize you must transform your strategy beyond aircraft maintenance to aircraft sustainment with the appropriate cost controls. You can do this with a predictive approach to maintenance that will sustain high reliability.

• NFF (No Fault Found) rates with failures after shop visits at both your internal shop and the OEM/MRO shop.

Applying a Hybrid Methodology to Extend Component Life
Since we implemented Lean Continual Improvement at FedEx Express, we are now resolving this type of situation by applying a hybrid methodology to the maintenance of avionics components to increase the service life of aging technologies. In the bench environment, the aviation maintenance technician usually performs much, if not all, of the routine troubleshooting and corrective maintenance tasks. For component level maintenance, the application of predictive maintenance (PdM) is a critical adjunct to lean manufacturing and is actually inherent to avionics maintenance. The analysis of data can enhance troubleshooting when used in conjunction with the Component Maintenance Manual (CMM). We combine PdM with a dash of Six Sigma and applied Lean Manufacturing tools of Root Cause Analysis along with approaching the component maintenance task methodically, much like a heavy airframe scheduled maintenance visit. In other words, we heavy check the box. This is a new way of looking at avionics component maintenance and would not be possible without the participation of the aircraft maintenance technicians. We collaborated with our OEM and concluded that the operating environment of the circuit chips, along with the age of the units required us to begin “soft timing” the circuits as the best solution for ensuring the longevity of the unit. The pressure of a mature product impacting an operation and the diverse requirements of an airline and an OEM can make it challenging to bring the two parties together for a common goal. In our Lean event, both parties performed separate Root Cause Analyses, which led to comparable conclusions about the cause of the basic failures. The teams came together and compared their findings, and the OEM was able to attain a first-hand understanding of our Jetrader 39

Evolve from a Test-Fix-Test Approach to Systemic Solutions
The traditional approach to Avionics Bench maintenance is to test-ﬁx-test a unit. At FedEx Express Avionics, we took a wider approach and along with an OEM, we examined the common causes of failure modes. This allowed us to invent a better solution to maintaining older avionics systems so we could sustain them systematically and consequently, more efﬁciently. The sustainment strategy was created from using a combination of Lean/ Six Sigma and Continual Improvement tools that can be described by six steps: • Go see the problem. (Lean) • Conduct research to determine the problem. (Six Sigma) • Identify solutions and prioritize actions. (Root Cause Analysis) • Implement and then verify results and adjust as necessary. (Lean/CI PDCA) • Develop long-term predictive maintenance for possible failures. (Six Sigma/Lean) • Coordinate supply chain enhancement arrangements and assemble OEM partnership solution teams. (Lean/CI)

Using PdM techniques help determine the condition of in-service equipment in order to predict when maintenance should be performed.

DENISE KAPPA / SHUTTERSTOCK.COM

What Made Us Change
What if you, as an operator, were faced with the following conditions on a key piece of avionics impacting your ﬂ eet? • Need to extend MTBUR (Mean Time Between Unscheduled Removals). • High piece part replacement of sub components.

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Jetrader - September/October 2011

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