It's Not a Fish Tank

It looks deceptively like a big aquarium -- with a robot as its caretaker.

In a University of Dayton laboratory, research engineer David Stubbs and colleagues have built a prototype ultrasonic inspection machine that looks for defects in expensive turbine engine disks in the military’s aging aircraft fleet.

Engine inspection and maintenance are huge concerns for the military, as it fights a battle in Afghanistan and prepares for war with Iraq.

Researchers say the work is significant for the U.S. Air Force because it’s much cheaper to inspect and put engine components back in service rather than replace them. These inspections could save the Air Force approximately $750 million by 2014 and bring new, high-technology commercial inspection services and system manufacturing business to Dayton.

The University of Dayton Research Institute is partnering with the Air Force Research Laboratory and three area firms -- Veridian, U.S. Inspection Services Inc. and General Electric Aircraft Engines -- to develop the next generation of jet engine inspection equipment. In the past three years, the Dayton Development Coalition and the area congressional delegation have worked to secure $14.8 million in federal funding for the Turbine Engine Sustainment Initiative (TESI). More than 25 UDRI researchers and five engineering students are working on the project, with plans to hire another five to seven researchers, according to Stubbs, director of UDRI’s Turbine Engine Support Center. U.S. Rep. Dave Hobson, R-Springfield, one of the project’s strongest supporters, traveled to Dayton March 10 to learn more about its economic impact for the region and the military.

“The return on investment is fantastic on this technology,” Stubbs said. “Turbine engine disks run anywhere between $30,000 and $300,000 per disk with approximately 20 disks per engine. If you have 500 engines in a fleet, we’re talking component costs totaling hundreds of millions of dollars. Congress recognizes the huge cost savings in inspecting the parts for safety and continuing to use them rather than replacing the components.”

Jet engine components are inspected regularly for cracks and other defects. Researchers are developing a new ultrasonic inspection capability to detect embedded defects in disks. They say the increased automation, sensitivity and reliability of the new equipment will help ensure the useful life of turbine engine disks, which are at the core of a jet engine.

The official cause of a 1989 plane crash in a Sioux City, Iowa, cornfield was an embedded defect in an engine disk.

Through the TESI program, UDRI is upgrading inspection equipment at the Oklahoma City Air Logistics Center. In the Shroyer Park Center on campus, UDRI researchers have built a prototype inspection system to detect embedded defects. The inspection process is centered around a standard industrial robot that inspects an engine component placed in a 300-gallon aquarium that sits on a machine shop turntable. The system automatically identifies the component, checks whether it’s centered through a digital camera, then picks up an ultrasonic probe that will allow it to find minuscule defects inside the engine component metal.

“As the tank and engine component spin around once every 10 seconds, the probe measures the ultrasound echoes and sends that information to a computer,” Stubbs said. “Using algorithms, we’re able to determine whether there are any critical flaws in the part. The algorithms that detect the defects are specific to each engine component and can be very complicated. At the end of the inspection, the system determines if a defect is truly present in the component without human interpretation of the data.”

U.S. Inspection Services, with headquarters in Dayton, is the fastest growing inspection and metallurgical services business in the country. It will install the new inspection equipment at its facility in Dayton. “The improved inspection capability would allow USI to seize a majority share of the aerospace inspection market,” said Jim Bailey, president of USI.

Veridian, which will manufacture the new inspection systems, is a leading manufacturer of engine inspection equipment for the Air Force and commercial inspection firms. This will move Veridian far ahead of its foreign competition, which currently offers much less sophisticated equipment, researchers say.

UDRI will simulate an inspection of an engine part this spring for the Air Force. A production-ready machine is expected to be available in late 2004.

“This program is an excellent example of the Air Force Research Lab teaming with technology leaders in Dayton to address a critical Air Force need and benefit the Dayton community,” said Mickey McCabe, director of the University of Dayton Research Institute.

UDRI performs nearly $50 million annually in sponsored research, much of it in aircraft safety.

March 13, 2003