Lord Corporation Awarded USAF Contract for C-130 In-Flight Propeller Balancing System

CARY, N.C., Oct. 11 /PRNewswire/ -- LORD Corporation - a leader in the management of vibration, noise and motion control - has been awarded a System Design and Development (SDD) contract by the U.S. Air Force (USAF) to integrate their proprietary Electro-Magnetic In-Flight Propeller Balancing System (EM-IPBS) into the USAF's C-130E & H fleet equipped with 54H60 propellers.

The $4.5MM contract from the 330th Aircraft Combat Sustainment Group (ACSG) of the Warner Robins Air Logistic Center (WR-ALC), Robins Air Force Base, Ga., spans until Dec. 2010 and includes extensive flight and user acceptance testing for their 500-plus C-130 fleet. The contract consists of a funded $2.7MM base effort and three unfunded options totaling $1.8MM.

Controlling propeller vibration is a new application for the existing technology of electro-magnetic active balancing. This benefits the USAF by reducing maintenance workload, improving aircraft readiness and improving the reliability of engine-mounted components on C-130 aircraft. Operating automatically during flight, EM-IPBS provides optimal propeller balancing by compensating for variations in balance, providing the balance correction needed throughout the entire operating range. The EM-IPBS also includes a small electronic controller that not only achieves on-line balancing, but also can serve as a predictive maintenance tool.

According to Steve Meyer, Global Marketing & Sales Manager, Aerospace & Defense, for LORD Corporation, controlling vibration with on-line, fully automated balancing technology will lead to reduced maintenance workload and will increase durability and lower the cost of operations.

"We are very excited about this contact and are grateful for the support the Air Force provided, including support from the many organizations involved such as Air Mobility Command and the National Guard Bureau," said Meyer. "The EM-IPBS technology looks promising as a means to reduce the maintenance load of the warfighter and lower the total life-cycle cost of the propulsion system."

Proven Technology

Although LORD teamed with Hamilton Sundstrand to adapt the robust in-flight system for turboprop aircraft, the IPBS leverages technology that has been well-proven by LORD in commercial applications. Electro-mechanical (EM) balancer technology has been in service in extremely harsh conditions in industrial applications for almost a decade and has logged millions of service hours in applications ranging from turbo-compressors to large extraction fans and high-speed machining spindles. EM-IPBS is comprised of one balancing device per propeller and a single controller per aircraft. The computer-controlled system uses accelerometer inputs from the rotating propeller to automatically adjust the position of correctional balance weights as needed to minimize total system unbalance for each operating condition.

According to Ray Misjan, Global Market Manager, Balancing, LORD Corporation, "Propellers are somewhat unique in that different amounts of imbalance result from their variable blade pitch, which can cause changes in both mass imbalance and aerodynamic imbalance. A variation in the required balance correction amplitude and angular position was indeed observed during the test. The IPBS technology is capable of actively responding to these variations and implementing balance correction, keeping the propeller vibration at minimal levels. IPBS is virtually the only way to properly balance propellers throughout their operating range."

Traditional means of dynamically balancing propellers -- adding counterweights -- allows for proper balance at one specific operating condition and for a limited amount of time since the propeller blade angle and aerodynamic loads change during flight. The negative effects of propeller imbalance vary from passenger discomfort to fatigue of on-board equipment. The effects of wear on the system also degrade balance over time. Significant costs are expended keeping vibration under control or simply monitoring its effects so as to predict potential failures. In comparison, the IPBS continuously repositions balance weights as needed during flight operation. The result is propeller balance maintained at the lowest possible level during the entire flight and reduced Direct Operating Costs.

A four-hour flight test was conducted in 2004 with sponsorship and oversight from the USAF Air Mobility Battlelab and engineering support from the Robins Air Force Base C-130 System Program Office (330th ASG). The demonstration began with the installation of an IPBS on a 54H60-91 Hamilton Sundstrand propeller system. Several typical flight profiles were conducted with the support of the 339th Flight Test Squadron of Warner Robins Air Force Base, Ga. Although vibration levels varied throughout the power spectrum on the 54H60-91 propeller, once activated, the IPBS proved it could maintain vibration levels at approximately 10 to 20 times less than any condition between thrust reverse (-6,000 inches-pounds torque) and maximum power (18,600- inches-pounds torque). Throughout this operating range, the required balance corrections varied in both amplitude and in angular position. In addition, the performance of the IPBS was unaffected by ambient air temperature from ground to 20,000-feet. The data gathered demonstrated that the IPBS is capable of performing required corrections automatically and reliably, with no additional workload for the flight crew.

According to Meyer, the tests demonstrated that the EM-IPBS concept is a robust in-flight system for turboprop aircraft that should produce significant operations and support savings, realized by eliminating the lengthy maintenance actions required to periodically balance propellers per the requirements. The reduced maintenance also will increase readiness by returning aircraft to the operational squadron earlier. Further, the large reduction in propeller vibration should provide a significant decrease in the maintenance cost of engine, gearbox and airframe mounted equipment. The high level of predictive maintenance afforded by IPBS also can be used to provide Prognostic Health Management (PHM) and diagnostics information to maintenance crews. Since the system results in less fatigue for both on-engine and on-board equipment, as well as lower failure rates, Direct Operating Costs (DOCs) are reduced.

About LORD

With headquarters in Cary, N.C., and sales in excess of $630-MM, LORD Corporation is a privately-held company that designs, manufactures and markets devices and systems to manage mechanical motion and control noise and vibration; formulates, produces and sells general purpose and specialty adhesives and coatings; and develops products and systems utilizing magnetically responsive technologies. With manufacturing in nine countries and offices in more than 15 major business centers, LORD Corporation employs more than 2,400 worldwide. Visit www.lord.com for more information.

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