The Mil Mi-6P, a unique passenger variant of the colossal Mi-6 Hook helicopter, never made it to full-scale production despite its potential for revolutionizing Soviet air travel. Featuring seating for up to 80 passengers, carpeting, and large rectangular windows, the Mi-6P aimed to meet Aeroflot Soviet Airlines’ demand for a civilian transport version of the Mi-6. However, the project was ultimately scrapped, with the sole demonstrator later transferred to the Soviet Air Force. While the Mi-6P’s fate remains unclear, its legacy lives on in future passenger aircraft concepts like the Mi-26P, showcasing Soviet innovation in aviation.
https://www.twz.com/news-features/the-story-of-the-monster-mi-6-helicopter-airliner