via: Commemorative Air Force · It was #OTD that Frank Piasecki piloted the first flight of the PV-3 prototype tandem rotor helicopter, in Morton Grove, Pennsylvania. Can you guess in what year? It may be earlier than you think! This helicopter, later designated as XHRP-X by the United States Navy, earned the nickname "the Flying Banana" due to its unique fuselage design facilitating vertical clearance between its rotors. Piasecki also became the first pilot to receive a helicopter license from the C.A.A. without having a prior airplane license. https://www.thisdayinaviation.com/tag/p-v-engineering-forum-pv-3/