Chief Warrant Officer 2 Chad Lange, an HH-60 Black Hawk helicopter pilot for Task Force Iron Knights, 2nd Battalion, 501st Aviation Regiment, 1st Combat Aviation Brigade, 1st Armored Division, performs a preflight check on the number one engine, which consists of fluid level checks, a damage inspection and foreign objects or debris check, prior to a maintenance test flight Jan. 2, 2015, Spriggs Airfield, Monrovia, Liberia. This ensures his helicopter is safe to fly and able to provide medical evacuations in support of Operation United Assistance in Liberia.