|JCAA National Strategy Executive Summary
The Joint Council on Aging Aircraft (JCAA) exists to coordinate the efforts of DoD Services andGovernment agencies in optimizing the service life of our aging aircraft fleets, to maximize aircraft material safety, to minimize aircraft operating costs and duplication of effort,
and to sponsor and conduct exchanges of information on these efforts. The Under Secretary of Defense for Acquisition, Technology, and Logistics has charged the JCAA to be the DoD focal point for addressing aging aircraft issues, with development of consolidated requirements and a strategy, as illustrated in Figure 1, prioritized roadmap, and investment plan for satisfying them. The JCAA has been organized operationally into 5 major steering groups of Subject Matter Experts, and these steering groups have conducted extensive bottoms-up analyses, reviewed reports and data (See Appendix B) resulting in concentration of effort across a tightly organized spectrum of projects of priority impact and interest to the services and agencies. These projects are arranged within 12 major strategic themes and are the thrust of this National Strategy.
1. Maintenance Training.
Current Maintenance Training Development Does Not Adequately Address Age Related Issues.
The equipment manufacturer as part of the systems development process develops most training courses. These courses provide the requisite experiences and certification attributes that must be learned in order to operate or maintain that system. As systems age, new failure mechanisms arise which can either introduce additional learning points or change the emphasis placed on existing course attributes.
The JCAA has surveyed two critical functional areas (wiring and corrosion), and determined that existing training for these areas is inadequate and needs to incorporate failure modes that are prevalent in our aging fleets. For example, aircraft wiring courses tend to focus on wiring identification and marking whereas the most critical maintenance problems with our aging systems tend to be chaffed wiring and repairs. A review of existing maintenance training will be conducted to ensure the course emphasis and certification requirements adequately match aging aircraft conditions.
2. Analytical Methods/Cost of Aging.
Detailed Analyses And Standard Processes Are Unavailable To Identify Cost Of Aging.
Despite various studies and surveys there is no cost community consensus on how to best model and estimate the cost of aging. This situation has resulted in a lack of accepted life cycle cost estimates, which drive proactive programming decisions to adequately fund the most likely costs of aging fleets. Efforts are underway to solve this requirement.
Current data available to decision makers indicates a growth in operating costs, i.e. “Costs per flight hour”, but these costs are often limited observations, may not include all operating costs and therefore, may present an inaccurate picture. Other more detailed and refined data is provided too late to influence management decisions. Detailed and standard processes for identifying costs contributes to more cost effective decisions and provides operational support where it is most needed. The JCAA will focus on development of DOD standards for operating costs and estimates, a cost community consensus, across services and platforms.
3. Corrosion Prevention.
Research is Needed for Next Generation Corrosion Preventative Compounds (CPC).
Despite corrosion being the number one source of maintenance man-hours in the aviation community, current corrosion preventative compounds (CPCs) lack the ability to provide protection for the time frame between depot periods, which hampers CPC effectiveness and requires thousands of additional man-hours. Numerous alloys (especially high strength steel) and applications do not have effective CPC materials and processes. The rapid mission and basing changes that are a fact of life for both commercial and military aircraft today are placing more pressure on our corrosion programs. The JCAA Corrosion Steering Group is coordinating a robust research, development and transition program of CPCs that will allow us to meet the challenging demand of a harsh environment and rapid deployment changes.
4. Transition of Commercial Products.
Resources Are Needed For Successful Transition Of Commercially Developed Products.
The aging aircraft community could better mitigate the effects of aging by transitioning commercially developed products from other sectors of industry. However, military and commercial aircraft requirements provide a challenging environment which requires components be analyzed and tested before these products can be used. Even when resources can be identified for acquisition, prototype test and logistics (training, supply and technical documentation) must also be modified to ensure commercially developed products are successfully transitioned to the aviation environment. Minimal resources are provided for platform specific testing and logistics.
5. Diagnostics/Health Monitoring Systems.
Insufficient Data Collection And Analysis Exists To Allow Effective Decision-Making And Incorporation Of Health Monitoring Systems.
Current data collection processes are inadequate to allow trend analysis on the cause of failure and location. In order to implement a corrective action to any system problem, the engineer needs accurate and timely information on the specific cause of failure and location. Many of our current data collection systems do not allow for mapping of system failures to individual components and are collected only on a macro level (corrosion). Other systems have only vague failure codes, which do not allow for detailed corrective action. The JCAA estimates that wiring failures are often counted as an avionics system causing wiring failures to be under reported by as much as 300%. DoD-wide changes are required to standardize wiring and corrosion data collection methods, failure reporting codes and zonal locations before effective systemic correction can be accomplished.
Health Monitoring Systems, which utilize prognostics and diagnostics, offer the potential to significantly reduce aircraft maintenance inspections. These systems, which provide indications of impending failure, allow aircraft maintenance to be scheduled only when required, instead of an inspection on a calendar basis, greatly reducing maintenance man-hours. However, to be totally effective, the incorporation of these systems requires analysis of specific failure information on the type and location of failures. Lack of a standard recording system hampers effective trade off decisions regarding Health monitoring Systems and is precluding effective incorporation.
6. Wiring Failure Detection/Condition Monitoring.
Multiple Technologies Are Required To Effectively Determine Wiring Condition/Failures.
Despite significant research with multiple technologies into wiring failure detection and isolation, differences in wiring harness construction routing and application require multiple technologies to effectively detect and isolate failures and impending failures. Commercial systems currently being modified by the Aging Aircraft community show great promise in identifying, isolating and reporting the pre-cursors to wiring failures. This preemptive approach greatly reduces maintenance man-hours and false equipment removals as well as providing for increased safety. However, as testing proceeds, it is understood that no “silver bullet” technology exists, and the pro-active maintainer must be provided with a robust toolbox of different diagnostic tools to effectively maintain our existing fleet.
7. Arc Fault Circuit Interrupt Equipment.
Arc Fault Circuit Interrupter (AFCI) equipment requires test equipment, remote reset capability and new policies.
AFCI equipment has the potential to provide significant safety and circuit protection against arcing conditions. However, the AFCI provides additional functionality and must be fielded with common test equipment and procedures to be fully effective. Future development programs that provide for remote reset capability must be continued so that AFCI capability can be fully incorporated throughout the aviation community. The JCAA considers the AFCI program to be one of our higher priority safety oriented efforts.
8. Structural Modeling and Analysis.
Existing Structural Models And Analysis Do Not Account For The Effects Of Aging And Changes In Operational Tempo.
Many existing structural health management strategies do not account for real life environmental impacts such as corrosion, but instead predominately rely on fatigue testing performed during aircraft development. These environmental factors, coupled with changes in operational use prevalent in today’s operating environment can cause early fatigue cracking, limiting service live and fleet availability.
Existing fatigue models are generally not updated nor evaluated as systems meet and exceed their original design lives, nor do they sufficiently incorporate widespread fatigue. Thus, these models are failing to account for aged materials, changed environments, and unanticipated operational usage patterns. Structural models must include the impact of corrosion on fatigue life. These models should include a teardown feedback loop and be dynamically updated in a community of practice in sharing data and models. Structural models should also be updated to support current practices in engineering where margins of safety are adequate but without risk reducing buffers.
Aging systems need the same rigorous systems engineering based analysis on a proactive basis as they approach and exceed their planned design lives.
9. Maintenance Manual Currency.
The process of updating many of our general series maintenance manuals and standards has been fragmented, under-funded, and uncoordinated, often resulting in out-of-date and ineffective procedures.
The common foundation for systems design and maintenance are the thousands of general series maintenance manuals and specifications that are referenced by many platform specific documents. Many of these documents are utilized as the basis for functional maintenance training or serve as the foundation for design and manufacturing. Funding and support for these common documents has been relegated to various services and agencies without any formal coordination, which means that if one service or agency’s budget is reduced, support for a critical document may be terminated without notification. In addition, since there is no single weapon system advocate or funding source, these general series documents do not have a system advocate for funding.
This lack of coordination and prioritization has resulted in obsolete processes and improper training procedures, which has resulted in increased maintenance costs. The JCAA is working to coordinate a joint industry and government process where critical common publications and specifications are reviewed and updated on a periodic basis, across the spectrum of users.
10. Obsolescence Management.
Obsolescence Management is uncoordinated and fragmented.
Mitigation of DMSMS/obsolescence is an integral part of systems design and development. However, management of obsolescence is often totally reactive, limited to finding parts for fielded systems or providing alternatives solutions to a proposed OEM redesign effort. Complicating this fact, the responsibility for obsolescence management is spread over many services, agencies, and industries. The Aging Aircraft community is partnering with industry, the acquisition community, and the DoD DMSMS Working Group to find innovative solutions that will mitigate DMSMS/obsolescence. This collaborative process requires adequate data and documentation be procured, training and predictive tools be incorporated, and cooperative efforts be established with the OEMs to include the application of rigorous systems engineering based logistical analysis for the full life cycle of a system/subsystem.
11. Avionics Modernization.
Avionics design must facilitate effortless incorporation of new capabilities and technology.
The heart of aircraft enabling mission capabilities is significantly derived from avionics systems. The transition to an aging aircraft force structure is placing increased reliance upon technology insertion for countering identified threats and/or for assuring mission viability; however, legacy avionics systems do not possess the required architectures (design and sustainment agility) capable of affordably accommodating inevitable life cycle changes. Evolutionary changes such as Viable Combat Avionics and Modular Open Systems Architectures will allow us to introduce new systems and aircraft that will be more flexible at a reduced cost.
12. Component Improvement.
A robust component improvement program is required for dynamic components, subsystems, and avionics.
As systems age, reliability deteriorates as components wear out. Commercial engine programs have a well-established component improvement program, which incorporate new technology and repair procedures during overhaul. This model has allowed commercial engine and reliability to remain steady despite years of in-service use. Despite advances in technology that could improve subsystem performance, no programs exist to adapt technology refresh and/or upgrade into dynamic components and other repairable subsystems.
Adequately addressing these strategic focus elements will contribute to our current and future aviation fleets operating longer, safer and less costly.