Pratt & Whitney Advanced Ducted Propulsor (ADP) Engine Test-590 in NASA Ames 40x80ft Subsonic Wind Tunnel. The Pratt & Whitney advanced ducted prop (ADP) demonstrator undergoing acoustic and fan performance testing. ADP technology could lead to decreased fuel consumption and noise. Shown here are NASA Ames engineers Peter Zell (left) and Dr Clifton Horne (right) preparing for a laser light sheet for a flow visualization test. Shown standing in the nacelle of the ADP is John Girvin, senior test engineer for Pratt & Whitney.