The CTMA Connector March 2002

Welcome to The CTMA Connector, a monthly newsletter designed to provide news and ideas about the Commercial Technologies for Maintenance Activities (CTMA) program.
The CTMA program is a joint Department of Defense/National Center for Manufacturing Sciences (DoD/NCMS) effort promoting collaborative technology development between industry and the DoD maintenance and repair facilities. This newsletter highlights ongoing projects, serves as a forum for promoting new project ideas, and provides other news of interest to the program. Our goal is to stimulate your participation and solicit your input. Feel free to submit items for the newsletter as well as any suggestions to make it more useful. More information about the program can be found at http://ctma.ncms.org/.
To subscribe or unsubscribe to the CTMA Connector, send a message to listmanager@ncms.org with "subscribe CTMANewsletter" or "unsubscribe
CTMANewsletter" in the subject line.

Register for the 2002 NCMS/CTMA Working Symposium on Sustainment: Strengthening America's Military Readiness.

We are pleased to announce that Lieutenant General Charles Mahan has agreed to participate as a speaker and panelist at the symposium. General Mahan will discuss Department of Defense needs relative to ground vehicles as well as take part in a panel discussion with other DoD speakers.

In addition to reviewing the needs of the Defense community, the Jacksonville symposium will include over 100 presentations on current project efforts under DoD sponsorship, multiple workshop opportunities to discuss new ideas for future projects, and talks by Ken Trammell (Executive Director, Marine Corps Materiel Command) and Captain Karl Yeakel (NADEP JAX).

This is a working symposium. All participants are expected to discuss their needs and actively seek solutions to common problems. Unlike similar conferences, the audience will be relatively small and conducive to discussions. In addition, we expect this symposium to result in concrete actions, with new projects being defined and pursued. Register by 25 March for the reduced Symposium rate, and don't forget to reserve your hotel room as soon as possible.Full Symposium details are found at http://ctma.ncms.org/.

The new CTMA Plasma Spray Booth Equivalency Unit “live” Tuesday, 12 March 2002 at Howmet Turbine Components Corporation, Whitehall, Michigan. Note the two white rectangular-shaped meters on the Metco 7MC console, with analog needles mid-range, indicating amperage and voltage, as verfied by the plasma plume light behind the closed door behind the Booth Equivalency Unit (i.e., “gun on”). The typical “calibration” performed on the unit is not “gun on”. Gas flows from the left into and through the unit (EG&G smart-flow turbines accurate to within +0.1% of reading), out the right-hand side and into the back of the 7MC console. It then flows through the gas rotometers on the 7MC console, enabling the operator to “dial in” the amount of gas required by the customer’s parameter sheet, and then to the plasma spray gun. Gas pressure and temperature are recorded on the Booth Equivalency Unit as well. Amperage is being sampled via a Hall-effect device, and voltage via voltage pick-ups. The Booth Equivalency Unit also measures water flow and water temperature both to and from the gun. All data are data-logged by the laptop computer via National Instruments LabView software, as programmed by Impact Engineering, Jackson, Michigan (Impact also manufactured the unit, which is a derivative of a 1992 Miller Thermal device that had much less accuracy and data logging via a clipboard. TubalCain Company Inc. proposed the layout of the new unit to NCMS from experience gained using the Miller unit.)

The Plasma Spray Booth Equivalency Unit is used to provide an extensive profile of the electric, gas and cooling water “signature” of individual booths. The produced database enables exact transference of plasma spray parameters from booth to booth. As a result, coatings can now be developed in one booth and transferred, immediately and successfully, to other booths via the generated booth “signature” databases. The original paper on the concept was “Plasma Spray Booth Equivalency” by Walter Riggs and Darryl Crawmer (Riggs, then atG.E. Aircraft Engines, and Crawmer, at Battelle Memorial Institute, profiled 23 plasma spray booths in the G.E. coatings vendor base using a previously immobile “stack” of diagnostics equipment located in the Battelle Columbus laboratory). Among the findings was that cumulative gaseous/electrical parameters variance exceeded 35 percent. A follow-on paper, “Plasma Spray Booth Equivalency II,” by Riggs and William S. Willen showed that the resultant parametric variance rendered coatings which would either pass or fail specification requirements, totally contingent upon which booth the coatings were sprayed in.

The data are now able to be exported to Microsoft Excel files for user-friendly graphing and analysis. TubalCain performs the diagnostics at the booth and produces graphical and analytical reports for the customers at the job site. The customer is provided with both the report and the Excel files; the customer can consult with TubalCain via telephone or Internet on coatings optimization after the diagnostics measurements. The company also performs metallurgical laboratory analysis of the plasma sprayed coatings, assists in Design of Experiments optimization of coatings parameters, and provides operator and engineering/laboratory personnel training.

Jacksonville Naval Air Station is the home of the Naval Air Depot (NADEP) for numerous Navy aircraft. The DEPOT provides a multitude of products to the Navy including aircraft Standard Depot Level Maintenance (SDLM), aircraft Phase Depot Maintenance (PDM), and fleet exchange component overhaul and repair. Aircraft such as the P3s, EA6Bs, and F14s that come into the DEPOT for refurbishment on regular intervals and emergency repairs currently undergo intensive leak testing.

Current test methods - Current leak testing at NADEP Jacksonville is accomplished essentially by three methods: the bubble solution method, pressure decay method and water immersion method. Each of these methods has limitations. For example, the bubble solution method is messy and difficult to spray in certain areas; the pressure decay method is limited by the pressure gauge accuracy; and the water immersion method is limited by the size of the water tank.

CTMA technology introduction - This CTMA project was initiated at Jacksonville in early FY 2000 to demonstrate the benefit of a new state-of-the-art leak test system using pressurized Helium. The Helium pressure supply was delivered by a highly accurate, automated portable test stand, known as the SMART Charge II, built by Vacuum Instrument Corporation. The leak detector was a Helium leak detector, known as the SOS (Speed Of Sound) detector, invented by Argonne National Labs under the CTMA program. The advantages over conventional means of leak detection include:

Results to date - The leak test consisted of a vacuum purge followed by pressurizing with Helium under a range of different pressures depending on the section of fuel system being tested. While pressurized with Helium, the SOS detector was used to “sniff” all the fuel system joints, fittings and component interfaces within the eight F-14 fuselage fuel cells and engine nacelle. Numerous leak paths were quickly identified and, interestingly enough, one SOS verified leak was not detectable using the bubble method or the pressure decay method. The undetected leak was very significant, as it was located in the engine nacelle, an area that requires high maintenance hours to access after aircraft buildup and has many high temperature ignition sources. Maintenance man-hours and safety are two major concerns for the Navy fleet and are crucial to the ability of the F-14 aircraft to keep flying and flying safely. Four additional F-14 aircraft have been tested using the Helium detection method with similar results. This truly makes the Helium detection system a significant improvement over the out dated current leak detection methods.