 The S-97 made its maiden flight on 22 May 2015.Sikorsky's earliest attempt at a fast compound helicopter with stiff coaxial rotors was the Sikorsky S-69 (XH-59A) flown in the 1970s.Its top speed was over 260 knots but its excessive fuel consumption, vibration and complexity requiring the full-time attention of two pilots led to the program's cancellation.