FAA Releases New Aircraft Engine Safety Tool To Industry
WASHINGTON - The Federal Aviation Administration (FAA) today released to industry a new computer tool designed  to reduce the disk failure rate in turbine-powered jet engines. The computer tool complements the actions announced  earlier by FAA Administrator Jane F. Garvey, that required enhanced inspections of engine fan disks to detect cracks that  are precursors to uncontained disk failures.

The disk design and life management tool, called "Design Assessment of Reliability with Inspection," allows engine manufacturers to improve disk structural integrity. The code runs on a computer workstation. Engine manufacturers can  use the code with their design systems as a FAA recommended method to meet a planned advisory circular on disk life management.

"This new tool represents a major breakthrough in our safety research program," said Steve Zaidman, FAA's Associate Administrator for research and acquisitions. "As part of the agency's Safer Skies Agenda, Administrator Garvey promised  to reduce the rate of accidents caused by uncontained engine failures, and this technology will help us accomplish that  goal."

Disks are heavy high-speed rotating parts inside an engine with attached fan blades that produce thrust. When the disk  fails, it can have catastrophic results. Fast-moving fragments from the disk can disable or damage the airplane. Undetected material or manufacturing flaws in turbine engine disks can undermine a disk's structural integrity. For example, investigators traced the 1989 fatal accident of a DC-10 at Sioux City to an undetected material defect in the disk  that resulted in an uncontained disk failure.

While historically the current engine rotor design and life methods have served the industry well, the new computer code  will enhance these methods by explicitly addressing these defects. Advances in nondestructive inspection and manufacturing process improvement through new technology, in conjunction with the announced engine inspection program, have significantly reduced the occurrence and enhanced the detection of these already rare defects. The application of this new tool will provide a further measure of safety by allowing disk designers to assume the potential  presence of tiny flaws in the design life determinations. This new method also will give insight into planning the most  effective inspection program.

This technology is the result of a four year FAA-funded research, engineering and development grant, sponsored by FAA's Engine and Propeller Directorate with the Southwest Research Institute (SwRI) in San Antonio, Texas. SwRI developed the tool in collaboration with engine manufacturers AlliedSignal, Rolls Royce-Allison, General Electric, and  Pratt & Whitney. Copies of the software are available to industry.