Ensconced Engine A KC-135 aircraft engine sits inside a new maintenance shelter at the headquarters of the Pennsylvania Air National Guard's 171st Air Refueling Wing near Pittsburgh, Dec. 12, 2018. Air National Guard Senior Master Sgt. Shawn Monk SHARE: Download: Full Size (1.71 MB) Tags: Air Force, national guard Credit: Senior Master Sgt. Shawn Monk VIRIN: 181213-Z-NQ177-1006C.JPG Photo Gallery