By Gary Rice

If you want to go with the flow in testing aircraft components, you have to do it accurately, and that’s what the Naval Air Depot Cherry Point’s two new flow meter calibrators are designed to ensure.

The calibrators were recently installed in the Calibration Lab in Building 137. The entire process from inception to acceptance of the calibrators at the depot took about three years, and three employees from the Industrial Production Support Division were key players in the project. Electronics Technician Keith Bushman, who writes local calibration procedures to support the Calibration Lab, first recognized the need for the machines and initiated the request. He and Mechanical Engineering Technician Tom Brown provided the mechanical engineering specifications, and Industrial Engineer Sheila Cuthbertson wrote the justification for the new machines.

“The calibrators were built according to our specifications based on our required usage and what we wanted to test,” Cuthbertson said.

“We have a lot of equipment throughout the facility used to test aircraft components, and they have to be accurate,” Brown said. “In order to ensure they are accurate, all of the equipment is on the calibration program, and some of the items that need to be calibrated are flow meters. We have to measure flow accurately to get repeatable and consistent results on test equipment. In order to calibrate, you have to use equipment that is far more accurate than the accuracy you’re attempting to achieve with the flow meters.”

There are three basic types of flow meters in use at the depot – turbines (modulated carrier and magnetic pick-off), positive displacement, and variable area – and they are used to test components in a wide range of aircraft systems, including hydraulic, fuel, and pneudraulic systems. Prior to installing the two new calibrators, depot technicians could only test the magnetic pick-off turbines type. The others had to be sent out to certified contractors or manufacturers for calibration.

“The new flow meter calibrators are super accurate testers that are used to standardize all of our flow meters,” Brown said. “They are far more accurate and versatile than the old machines and can calibrate all of the various types of flow meters used here at the depot.”

The Flow Dynamics Company in Scottsdale, Ariz., built the two flow meter calibrators. They were delivered to the depot on March 12 and were installed and operational by March 21. The larger one is about 15 feet long, and the smaller one is about six feet long. The company also trained and qualified two depot Calibration Lab technicians as operators.

There is a very accurately machined cylinder in the tester, which is filled with a known quantity of calibration fluid. Using a semi-automated process, air pressure is used to shoot the fluid through the flow meter, and the calibrator’s computer calculates the flow.

“Not only can we now test all of our flow meters here at the depot,” Cuthbertson said, “but the test turnaround time for the magnetic type meters has decreased from three or four hours to only 30 minutes. These are significant enhancements in the depot’s maintenance capability, and as a result, we are able to save the government a great deal of time and money.”

The Naval Air Depot Cherry Point provides maintenance, engineering, and logistics support on a wide variety of aircraft, engines, and components for all branches of the U.S. armed forces. The depot’s mission is to support the Naval Air Systems Command (NAVAIR) in providing the American warfighter with absolute combat power through mastery of six broad categories of naval aviation technologies: sensors, aircraft, weapons, training, launch and recovery, and communications. Employing almost 4,000 people, the depot is the only source of repair within the continental United States for many jet and rotary wing engines. It is the Navy’s center of excellence for rotary wing aircraft, providing engineering and logistics support for all Navy helicopters.

Photo Caption: In the Naval Air Depot Cherry Point Calibration Lab in Building 137, Electronics Technician Bill Craig (left), one of the depot’s two trained operators, explains the finer points of flow meter calibrator operating procedures to Industrial Engineer Sheila Cuthbertson and Mechanical Engineering Technician Tom Brown. (Photo by Gary Rice)