PREFLIGHT CHECKS Army Chief Warrant Officer 2 Robert Childers performs preflight checks on a CH-47 Chinook helicopter before a mission supporting Operation Northern Strike 2014 on Alpena Combat Readiness Training Center in Alpena, Mich., Aug. 5, 2014. Childers is a pilot assigned to the Illinois Army National Guard's 2nd Battalion, 238th General Support Aviation Regiment. Operation Northern Strike is a joint multinational combined arms exercise. SHARE: Download: Full Size (0.05 MB) Credit: VIRIN: 555417-G-NOT30-585.jpg Photo Gallery