PA-97 Heli-Stat

The Piasequin PA‑97 Heli‑Stat was the first dedicated vertical‑take‑off and landing (VTOL) platform to combine helicopter lift with fixed‑wing cruise efficiency. Designed by Frank Piasecki’s company in the early 1960s, the prototype first flew on 1 June 1965 and entered a brief flight‑test program before funding was withdrawn in 1967. The aircraft featured a coaxial rotor system that supplied lift and a pair of pusher propellers mounted on short wings to provide forward thrust, allowing transition from hover to high‑speed cruise without the drag penalties of a conventional rotor‑blade. Its lightweight aluminum airframe, tilting rotor hub, and thrust‑reversing capability gave a maximum speed of 250 km/h and a service ceiling of 6 500 m, while retaining the ability to hover within a 30‑meter radius. Although only two prototypes were built, the PA‑97 demonstrated the feasibility of hybrid VTOL concepts and directly influenced later projects such as the V‑22 Osprey and modern tilt‑rotor drones. The Heli‑Stat remains a landmark in aviation history for pioneering the integration of rotorcraft lift and fixed‑wing performance in a single, compact airframe. Today, a restored is displayed at the National Museum of the United States Air Force, where it continues to inspire engineers working on next‑generation electric VTOL vehicles.