ARNOLD AIR FORCE BASE, TENN. — Dr. Doug Garrard, AEDC senior staff engineer, explains testing operations in the Aerodynamic and Propulsion Test Unit at the Complex to members of the National Aerospace Solutions, LLC Technical Advisory Board Sept. 9, 2016. APTU is a blow-down, true temperature and pressure test facility designed for testing the performance, operability and durability of supersonic and hypersonic missile scale flight system hardware including propulsion systems and materials. The NAS TAB members toured several test facilities with the AEDC Test Operations and Sustainment contractor. Pictured left to right is Dr. Wesley Harris, with Massachusetts Institute of Technology; Dr. Krishan Ahuja, with Georgia Institute of Technology; Garrard; Dr. Woodrow Whitlow, NAS technical director; Dr. Edward White, Texas A&M University; and Doug Pearson, NAS deputy general manager. (U.S. Air Force photo/Holly Peterson)