It takes more than wrenches

Feb. 1, 2003

It Takes More Than Wrenches
To maintain an airplane nowadays

By Fred Workley

Fred Workley

Technology is marching on! Aircraft maintainers have a lot more tools available today than just a set of wrenches. One example is the Navy's Super Hornet F/A-18 (models E&F) which is a "paperless aircraft." This complex aircraft has taken the step past BITE (Built In Test Equipment) by employing built-in component usage measurements to drive maintenance scheduling. At the same time it places heavy demands on both operators and maintainers of the aircraft when it comes to management of the maintenance program and the large volume of associated information. This is done with the latest maintenance information technology and has become an electronic logbook.
Just imagine this type of system on the aircraft that you maintain. No more handwritten logbooks. No paper revisions. No more microfiche. No more CDs. But along with maintenance you are now being called an IT professional. Yes, you are now "IT," an information technology professional.

According to the Journal of Business Logistics, 2000-21(2), pp.173-186, modern information systems perform three vital roles: (1) they support business operations, (2) they enhance managerial decision making using decision support systems (DSS), and (3) they provide a strategic competitive advantage. The way I interpret this is that, for the life cycle of the airplane, maintenance tasks are integrated to the supply chain so that you get the parts that you need, just in time, to fix the airplane when it is available to you so that there is no unnecessary downtime. In other words "Keep 'em Flying."

Maintenance at the component level
This maintenance information technology can provide component centered equipment data at the serial number level. It provides a system that can schedule maintenance based on an elaborate combination of measured parameters and/or calendar time to determine when maintenance is due, again at the component level. It allows forecasting of maintenance requirements to take advantage of the aircraft's availability to meet certain maintenance scheduling opportunities. It functions "enterprisewide" anywhere at any time. This system enables an automated interface to data recorded in-flight to ensure that maintainers are not burdened with a very intensive data input. It permits total fleet visibility for more than 750 aircraft and 2,000 engines. It tracks configuration, status, and confirms maintenance management.

Maintenance data is stored while at remote sites like aircraft carrier groups that are running silent. This fleet data is then transmitted by Internet or Extranet back to the central database once the network connectivity is permissible. This allows fleetwide forecasting of upcoming spare parts and resource demands. This same technology is also used to transmit maintenance plan revisions from headquarters to affected sites where the local systems are automatically updated. This system now has the ability to transfer the whole maintenance record (log) from site to site, wherever the airplane lands. The line-level maintenance technicians like it because of its ease of use. It enables technicians to devote more of their time to actual maintenance tasks and less to data entry and complicated reporting.

Total life-cycle system management
The goal for any military or civilian airplane over its life cycle is maintainability, reliability, and sustainability. Total life-cycle system management improves sustainment by establishing clear responsibility and accountability to meet reliability and performance from acquisition to the end of economic useful life. Terms like end-to-end distribution are starting to be referenced by recent aircraft offerings. Aircraft manufacturers are offering programs by providing parts support, upgrades, configuration documentation, associated maintenance information, and data packages as part of the acquisitions cost. In some cases this has included heavy maintenance visits in factory-authorized facilities.

The result of these offerings has been to influence aftermarket maintenance opportunities for third-party maintenance providers. End-to-end distribution controls acquisition of spares, sourcing of maintenance, and positioning of spares and material to facilitate the flow to the end user. The effect on the supply chains is a move toward virtual integration. This means that a parent company might own all the activities across the supply chain to ensure reliability of raw materials and resources. This controlling of all resources is less common in the aviation industry. Instead, outsourcing has been successful. Outsourcing is often at arms-length and involves a part or service with defined engineering features. Thus there may be multiple sources for these parts or components.

Predicting equipment failures
Sometimes it has been said that we "wear out the airplane taking it apart to inspect it so that we can fix it." Consider Condition-Based Maintenance Plus (CBM+). Instead of waiting till something breaks we can now predict failures on equipment to implement broad-based planned maintenance programs. CBM+ is intended to provide more accurate predictions of impending failures based on condition data, which would result in maintenance savings and better reliability. CBM+ is a blend of improved maintenance capabilities and sound business processes. It involves the integration of parts supply systems and business practices to result in a responsible "logistics system." I predict that you will see the commercial logistics system talked about more frequently in the future. The use of the term "logistics system" for civilian aircraft includes enhanced diagnosis and prognosis techniques, serial number item management, automatic identification technology like bar coding and microtagents, active failure trend analysis, web-based portable electronic or on-site point-of-maintenance aids, as well as data-driven interactive, cost/benefit analysis maintenance training.

The ultimate goal of these current and future initiatives is to increase operational availability and reliability throughout the life cycle of the aircraft and to learn from the collective experience of the whole fleet. This should reduce owning and operating costs. This forces you, the maintainer, with your knowledge-skill sets and tools, both wrenches and diagnostic tools, to maintain your complex aircraft at the optimal time for maintenance through the use of available technologies. These technologies, some of which you will adopt in the near future, will improve your maintenance decisions by getting it right the first time and avoiding no-fault-found situations for parts, through integrated logistics processes.

Off-the-shelf items
Another trend that I predict is that you will see more commercial off-the-shelf items (COTS) on aircraft. They will still have PMAs (Parts Manufacturing Authority) and possibly be installed with STCs (Supplemental Type Certificates) but the parts were designed and developed for some other industry than aviation. This process has been labeled as enterprise integration when referring to the business logistics system. An example of this is the fiberoptic sensors that can look at the oxygen content of the ullage in a fuel tank to determine the amount of nitrogen from an on-board supply necessary to be metered into the tank to reduce the flammability level. This technology was developed for other industries but now has an application on aircraft. Another example is software. The airplane has to be able to translate information in the form of data to the maintainer's laptop or PDA. Somehow, we as an industry have to minimize the impact of software change by identifying common, reusable business practices that are assumed by all the software suppliers. Near real-time, actionable information provided by modern, up-to-date commercially available software products makes life easier and makes the electronic logbook possible. But it is really frustrating when you upgrade to the latest AOL.8.0 or MSN8 and you find out that your existing systems no longer work.

An all-electric airplane?
The end is near! The end is near! Yes the end of the circuit breaker is at hand. Computers can control the power distribution on aircraft and any integrated platform. Solid-state power control technology (SSPC) provides integration and replaces circuit breakers. This automatic power load management will eventually lead to an all-electric airplane. It provides load shedding and distribution in emergencies as well as monitoring utility system performance. These systems permit variable frequency power on systems using distributed power in avionics systems. The end result is intelligent load management. You will be able to program SSPC from your laptop.

About a year ago I wrote an article titled, "Computers are Wonderful" in which I predicted that maintenance technicians would have to become very good at "keyboarding." The article cautioned you to protect your data and trade secrets. Well besides that, you now need to be information technology professionals. Keep 'em Flying.

Fred Workley is the president of Workley Aircraft and Maintenance Inc. in Alexandria, VA, Benton City, WA, and Indianapolis, IN. He holds an A&P certificate with an Inspection Authorization, general radio telephone license, a technician plus license, ATP, FE, CFI-I, and advance and instrument ground instructor licenses.

About the Author

Fred Workley