Under Secretary of the Air Force visits Arnold AFB

  • Published
  • By Jill Pickett
Kirk Butler, director of operations for the Hypersonic Systems Test Branch, Test Division, Arnold Engineering Development Complex (AEDC), explains how the Aerodynamic and Propulsion Test Unit (APTU) operates to Under Secretary of the Air Force Gina Ortiz Jones, during her visit to Arnold Air Force Base, Tenn., headquarters of AEDC, Nov. 5, 2021. APTU is a combustion-heated, blow-down wind tunnel used to evaluate the performance of hypersonic air-breathing propulsion systems. (U.S. Air Force photo by Jill Pickett)