F/A-18E/F Full Scale Structural Fatigue Test Results

The F/A-18E/F structural airframe consisting of the wings, fuselage, and empennage has completed an extensive full scale fatigue test program in 2004. This test of the Engineering and Manufacturing Demonstration (EMD) configuration of the airframe completed three lifetimes, or 18,000 simulated flight hours (SFH), of cycling and is currently involved in a structural teardown and evaluation. This test article is referred to as FTSO. In addition, the United States Navy authorized a significant structural change to the F/A- 18E/F forward fuselage and wing to support a cost reduction initiative. A separate full scale structural fatigue test was also performed on these configurations of the forward fuselage and wing airframes. These test articles are referred to as FT76 (fuselage) and FT77 (wing). The FT76 fuselage test article was cycled for two lifetimes (12,000 SFH) and the FT77 wing test article was cycled for three lifetimes (18,000 SFH). This paper will discuss the test programs including the structural configuration of the test articles, test spectrum content, fatigue failures experienced during testing, and results of the structural inspection effort conducted during the teardown of the test articles. The paper will also document the process that was collaboratively developed by Boeing and the U.S. Navy to perform the teardown procedure and extract all desired data from the test articles.