LANGLEY AIR FORCE BASE, Va. -- Airmen of the 1st Component Maintenance Squadron run a test on the final F-100-Pratt Whitney-100 engine at the test cell, or hush house, here Jan. 30. The F100-PW-100 engine is one of the oldest engines used for military operations. After almost four decades of powering the F-15 Eagle, this engine has been replaced with a much stronger engine, the F100-PW-220. (U.S. Air Force photo/Airman 1st Class Vernon Young)