American Helicopter Society (AHS) 70th Annual Forum

MONTREAL, QUEBEC CANADA (May 21, 2014) — Mr. Greg Wood of MERC presented a technical paper at the American Helicopter Society (AHS) 70th Annual Forum in Montreal, Quebec on May 21, 2014. Greg’s paper was titled Extension of HUMS Data for Estimating Flight Severity for Helicopter Airframe Structures.

This paper details the development of a flight severity factor (FSF) calculation algorithm for airframe components by leveraging flight parameter data from a Health and Usage Monitoring System (HUMS). The United States Air Force (USAF) has added to the value of its HH-60G Pave Hawk HUMS data by using it to estimate theoretical fatigue crack growth, which is leveraged to update inspection intervals per MIL-STD-1530C.

The results yield increased safety, improved component inspection and replacement scheduling, reduced unscheduled maintenance, decision support for service life extension programs (SLEP), and increased aircraft availability.

In addition, the FSF is being used in the implementation of an individual aircraft tracking program (IATP) for the HH-60G, using HUMS data to predict theoretical crack growth on a flight-by-flight basis for two structural tracking locations, with an additional six planned for the near future.

The paper describes background for the program, including a flight strain survey, a global finite element model, and a durability and damage tolerance analysis used for the damage model.

About Mercer Engineering Research Center

Mercer Engineering Research Center (MERC) is the research and applied engineering arm of Mercer University, a private university founded in 1833. For over 175 years the University has served Georgia as a highly-respected educational institution. In 1984, the School of Engineering was established at the Macon, Georgia campus, with the charter class beginning studies in 1985.

Two years later, in 1987, the Mercer Engineering Research Center was established under the School of Engineering to provide locally available engineering and scientific services and critical specialized technical skills. Today, MERC functions as a non-profit operating unit of the University, with the Executive Director, Dr. David Barwick, reporting directly to the University president, Mr. William D. Underwood.

To learn more, please visit MERC's website at