Piasecki PV-3 was the first successful tandem-rotor helicopter, developed in the mid-1940s by Frank Piasecki's P–V Engineering Forum. It was famously nicknamed the "Flying Banana" due to its distinctive upward-curved rear fuselage, a design choice made to prevent the two large rotors from colliding during flight. Development and History Origins: The PV-3 was developed under a February 1944 contract from the United States Navy, which designated the prototype as the XHRP-X. First Flight: The proto