December 23, 2003 (by Eric L. Palmer) - Widespread engine problems with F-15 and F-16 fighters are forcing maintainers to perform frequent inspections while the Air Force starts an engine redesign. The engines are Pratt & Whitney F100-PW-100, -200 and -220 power plants that went through modifications as part of the "reliability enhancement" program that started in the late 1990s.
The potentially defective engines affect 45 percent of the service's 1,380 F-16 Fighting Falcons and 80 percent of the 740 F-15 Eagles.
Blades in the fourth-stage low-pressure turbine near the rear of the engine were replaced during the enhancement modifications. Those replacement blades are now cracking.
Ironically, the defective blades were intended to help solve problems that led to crashes of several jets. Air Force wide inspections of the fourth-stage turbines have discovered about 300 blades since July that show signs of fatigue such as microscopic cracks.
Concerns about the fourth-stage turbines developed after the crash of an F-16 assigned to the 56th Fighter Wing at Luke Air Force Base, Ariz. An investigation turned up a blade that hadn't been manufactured to specifications and broke loose inside the jet's PW-220 engine.
Source: Air Force Times, December 29, 2003 (page 14)