LANGLEY AIR FORCE BASE, Va. -- Chief Master Sgt. Scott Dearduff, command chief for the 9th Air Force and U.S. Air Forces Central Command,is given a tour by Master Sgt. Robert Casagrande, Air Combat Command airborne systems chief, of the POW/MIA memorial here Sept.11. Chief Dearduff took the tour to better understand how Langley operates and to see how Airmen carry out the everyday mission.(U.S. Air Force photo/Airman1st Class Jonathan Koob)