Featured in the Saunders-Roe book, the Saro-Hiller XROE-1 Rotorcycle G-APYF was the only civil-registered example of ten built. Six, including this one, carried Class B marks, so what were the other four and what happened to them all?

Самолёты на фотографии: Aircrafts on the photo: Hiller ROE-1 Rotorcycle - СШАUSA - 1957