Undetectable material and manufacturing anomalies represent a departure from the assumed nominal conditions. To quantify the extent of such occurrences, the FAA requested reconstitution of the SAE ad hoc committee on uncontained engine failures in 1990. While no adverse trends were identified, concern has been expressed that the projected increase in airline passenger traffic at a rate of some 3.5 percent per annum will lead to a noticeable increase in the number of accidents per year. Engine uncontained rotor events, which in their own right should not result in a catastrophic accident, have done so in conjunction with other adverse circumstances.

As a result of the accident at Sioux City in 1989, the FAA requested in 1991 that industry, through the Aerospace Industries Association (AIA), review available techniques to see whether a damage tolerance approach could be introduced to produce a reduction in the rate of uncontained rotor events. The industry working group concluded that additional enhancements to the conventional rotor life management methodology could be established which explicitly address anomalous conditions. In response to the AIA recommendations, the FAA Titanium Rotating Component Review Team Report and AGARD, NASA and Air Force experience and recommendations on damage tolerance concepts and operational experience for gas turbine disk alloys, this program was initiated in 1995.