Regional jets, particularly their engines and components, are emerging as a major growh driver in the commercial transport MRO market. According to the fleet database compiled by New Haven, Conn.-based BACK Aviation Solutions, regional jets accounted for just 4% of the world commercial jet fleet in January 1994, with 338 units. This grew to 2,058, or 13%, by January 2004. BACK predicts that by 2014, the number of regional jets will reach 3,847, or 24% of a total worldwide jet fleet of 16,030.

For the past 25 years, most new production airliners have been certified with factory maintenance programs based on the Maintenance Steering Group (MSG) concept, known since 1980 as Maintenance Steering Group 3 (MSG-3). While commercial aircraft OEMs have adopted the evolving maintenance standard, most business jet manufacturers to date have not.

Of the 631 Sabreliner jet aircraft produced between 1963 and 1981, military and government sales accounted for 191. The U.S. Air Force bought the lion's share, with 149 originally purchased under its Utility Trainer Program (UTX). Only four months after North American Aviation flew the first T-39 prototype in September 1958, the Air Force placed its first production order for 143 T-39As and six T-39Bs. Both aircraft types were powered by two Pratt&Whitney J60 jet engines, each rated at 3,000 pounds of thrust at sea level.