Workers with Henley Construction and Welding Unlimited install an F100 engine for display outside of the Engine Test Facility at Arnold Air Force Base. The installation of the display was completed in late 2019 and coincided with the 50th anniversary of the first operation at Arnold AFB involving the F100, which occurred on Dec. 18, 1969. Since then, Arnold Engineering Development Complex has logged over 23,000 hours testing the F100 series of engines in numerous test facilities. (U.S. Air Force photo by Bradley Hicks) (This image was altered by obscuring badges for security purposes.)