LORD Corporation Announces Successful Flight Test Results of In-Flight Propeller Balancing System on C-130

This testing is part of a System Design and Development (SDD) contract received from the USAF for the integration of LORD Corporation's proprietary In-Flight Propeller Balancing System (IPBS) into the USAF's C-130H fleet equipped with 54H60 propellers.


CARY, N.C., Oct. 6, 2011 /PRNewswire/ -- LORD Corporation -- a leader in the management of vibration, noise and motion control -- has completed extensive testing of pre-production hardware of their In-Flight Propeller Balancing System as part of a $4.5-million contract with the U.S. Air Force (USAF).  

The testing, which was the second development test and evaluation (DT&E) of the technology, was completed and has transitioned into a year-long operational test and evaluation (OT&E). This testing is part of a System Design and Development (SDD) contract received from the USAF for the integration of LORD Corporation's proprietary In-Flight Propeller Balancing System (IPBS) into the USAF's C-130H fleet equipped with 54H60 propellers. The contract from the 330th Aircraft Sustainment Group (ASG) of the Warner Robins Air Logistic Center (WR-ALC), Robins Air Force Base, Ga., was awarded in late 2008 and spans until December of this year. Consisting of a funded $2.7MM base effort and three unfunded options totaling $1.8MM, the contract includes extensive flight and user acceptance testing for their 500-plus C-130 fleet.  

Proven Technology
Although this technology is new to the aerospace industry, LORD Corporation's balancing technology has been in service in extremely harsh conditions in industrial applications for almost a decade. It has logged millions of service hours in applications ranging from turbo-compressors to large extraction fans and high-speed machining spindles.

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. Further, significant costs are expended keeping vibration under control or simply monitoring its effects so as to predict potential failures. In comparison, the IPBS continuously adjusts balance during flight operation. The result is propeller balance maintained at the lowest possible level during the entire flight and reduced Direct Operating Costs (DOCs).

The system 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 balance as needed to minimize total system imbalance for each operating condition.  In addition to managing the IPBS system, the small electronic controller also can serve as a predictive maintenance tool.

According to Justin P. Manna, Business Development Manager 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. This benefits the USAF by reducing maintenance workload, improving aircraft readiness and improving the reliability of engine-mounted components on C-130 aircraft."

Proof in the Numbers
The testing process actually began several years ago. 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.

This content continues onto the next page...

We Recommend