February 11, 2008

NC State’s IMST Keeps Helicopters Off the Ground

  — NC State engineers partner with NAVAIR engineers to solve aging aircraft maintenance problems with “off-the-shelf” technology

CH-46 Sea Knight helicopter in flight. (Photo: U.S. Navy)

More than 16 feet tall with six rotor blades greater than 25 feet long, the CH-46 Sea Knight is one of the US Navy’s largest helicopters, providing reliable military transport since its introduction in the late 1950s. With an average age of 37 years, CH-46 helicopters have maintenance issues related to their age and are scheduled for phased retirement in 10 years. Parts are difficult to obtain for the 200 or so still in service.

Faculty, staff and students from the Institute for Maintenance Science and Technology (IMST) in the College of Engineering at North Carolina State University have partnered with the Naval Air Systems Command (NAVAIR) engineers at Fleet Readiness Center (FRC) East, Cherry Point, to solve real-time engineering problems of the CH-46 helicopter and other aging aircraft at the NAVAIR Depot.

Dr. Jerome J. Cuomo, Distinguished Research Professor in the Department of Materials Science and Engineering (MSE) and director of IMST, and IMST co-directors Dr. John S. Strenkowski, associate dean for research and graduate programs in the College of Engineering, and Dr. Roger C. Sanwald, program manager-senior engineer in MSE, have been working with NAVAIR Depot engineers since 2004, providing technical support on an as-needed basis.

FRC East is one of six naval aviation maintenance operations in the continental U.S. responsible for ensuring the safety and reliability of the CH-46 and other military aircraft. For nearly 60 years FRC has provided timely, cost-effective, quality engineering; maintenance; and logistical support for Department of Defense aviation. Highly skilled engineers and production artisans work around the clock to move aircraft quickly and safely back into service. FRC East is eastern North Carolina’s largest industrial employer.

Chris S. Holder, NAVAIR group head of research and engineering at Cherry Point, appreciates the advanced technical support IMST faculty, staff and students provide.

“We are engaged with fleet support,” explained Holder. “NAVAIR can get parts from OEMs [original equipment manufacturers] for newer aircraft but not for older aircraft. We need smart people to spend more time on little S&T [science and technology] as opposed to big S&T.”

“Our job,” said Sanwald, “is to find out what 'off-the-shelf' technology is available.”

Drs. Jerry Cuomo (l) and Roger Sanwald examine the tip light on a CH-46 Sea Knight rotor blade. (Photos: Kathi MCblief)

The repair of tip rotor lights on the CH-46 is a good example of applying “off-the-shelf” technology to solve a maintenance problem. On the CH-46 there are lights at the end of each rotor blade for night flying. When wires of a tip light malfunction, repair is cumbersome because the wires are embedded in the structure of the blade.

“One of our challenges was to develop a new set of replacement wires able to withstand high forces,” said Sanwald.

“We analyzed the current wire system, suggested design improvements and found a more durable copper wire that met specifications,” said Thomas Hunter, a research engineer at IMST.

The IMST project team found one company to manufacture the wire and another to provide insulation for a small order — 8,000 feet — of wire that was double in strength.

“Double-strength wire and other design changes mean fewer man hours for maintenance,” Sanwald pointed out.

Not content with these improvements, the IMST design team is exploring the feasibility of a wireless tip light enhanced with infrared to improve mission capabilities.

IMST engineers and students are working on a number of other projects at Cherry Point, including projects for the Vertical Lift Center of Excellence. One project includes work on an additive manufacturing process to produce “near net shape parts on demand”; another provides metallic coatings on selected parts by propelling small metal particles at high velocity that bond to the surface of the part.

These projects and many others provide undergraduate and graduate students at IMST with invaluable research experience, making them attractive to potential employers.

Hunter says two students on the tip-light project attribute their jobs to their work on the project. One received a job with a vendor as head of a materials science and engineering department; another is working for the U.S. Navy in Maryland. A third student, who worked on other NAVAIR projects, is working for the U.S. Army in Huntsville, Ala.

Clearly, NC State’s partnership with NAVAIR benefits many. In addition to providing technical support to NAVAIR Depot Cherry Point, as well as the U.S. Coast Guard Air Station in Elizabeth City, IMST helps small manufacturing companies in the state to become qualified to manufacture aircraft parts and implement agile manufacturing technologies that will allow for low-volume production, flexibility and profit.

— mcblief —

Technical Contact:
Dr. Roger Sanwald, roger_sanwald@ncsu.edu, 919-513-2478

Media Contact:
Kathi McBlief, kathi-mcblief@ncsu.edu, 919-515-2283

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