In an effort to prevent widespread fatigue damage (WFD), the Federal Aviation Administration (FAA) released a Notice of Proposed Rulemaking (NPRM) at an estimated industry cost of $360 million, proposing age limits on aircraft and prohibiting operation beyond those limits. The NPRM, which applies to aircraft with a max takeoff gross weight of 75,000 pounds, would encompass the Embraer and Bombardier regional jets as well as the older British Aerospace 146s and F28s.

While the age of the fleet is declining, the FAA noted that all aircraft are susceptible to WFD and current requirements to prevent WFD are inadequate. "To address WFD, we need a proactive approach," said the agency. "I.E., address conditions affecting safe flight that we know can happen--before they happen. This approach would require persons to analyze the causes of WFD in relation to the entire airplane and to analyze repairs, alterations, and modifications installed on the airplane.

The NPRM [Docket No. FAA-2006-24281; Notice No. 06-04 Aging Aircraft Program: Widespread Fatigue Damage) requires manufacturers to establish operational limits on transport category aircraft saying the danger of WFD is unknown past a certain point in the life of an aircraft. Type certificate holders would be required to develop the limits based on an evaluation of WFD susceptibility, both for existing airplanes and for proposed future certifications. The proposal also calls for maintenance actions to prevent WFD before an aircraft reaches its operational limit and in repairs, alterations or modifications which must be set down in any service information or maintenance programs.

Currently, manufacturers of newer aircraft must prove that WFD will not occur. In addition, there are no prohibitions against operating an aircraft beyond the expected service life determined by its manufacturer. The proposal would prohibit operation of an aircraft beyond its limits unless the operator has incorporated an extended operational limit and any necessary service information into its maintenance program.

The rulemaking is a further outgrowth of the 1988 Aloha accident in which a portion of the fuselage ripped off in flight. Ironically, it does not cover aircraft under 75,000 pounds, which, if in place last year, would have captured the Chalk's Grumman aircraft that went down off Florida.

The agency indicated benefits to the NPRM would be $726 million of accident prevention benefits and $83 million of detection benefits (averted accidents and maintenance cost savings) for total benefits of $809 million. The cost of this proposal, estimated over 20 years, is $360 million and the FAA estimates that airplane manufacturers would incur approximately 10% of these costs, while the remaining 90% of these costs would be borne by operators. Comments are due July 17, 2006.