From left: Mr. Charles Stevens, Turbine Engine Division Lead Engineer, Aerospace Systems Directorate, Air Force Research Laboratory; Dr. Dale Carson, Technical Advisor Propulsion, Engineering Directorate, Air Force Life Cycle Management Center; Mr. Ian Whittel; and Dr. Chuck Cross, Chief of Turbine Engine Division, Aerospace Systems Directorate, Air Force Research Laboratory, stopped for a group photo during a tour of AFRL at Wright Patterson Air Force Base, Ohio, Oct. 31, 2017. Whittle is the son of the late Sir Frank Whittle who is credited for inventing the gas turbine engine effectively launching aircraft propulsion into the jet age. (U.S. Air Force photo / Lisa Donauer)