HISTORY

The Piasecki Helicopter Corporation was founded in 1940 by Frank Piasecki as the P-V Engineering Forum. It first become known as Piasecki Helicopter in 1946. To fund expansion, Piasecki sold 51% interest in the company to Laurance Rockefeller and Felix du Pont, Jr. for $500,000. A conflict eventually developed and in March 1955 Piasecki was removed from leadership of the company.  Four months later, Piasecki left to form a new company, Piasecki Aircraft Corporation to pursue the development of compound helicopters and other rotorcraft.  In two successive special stockholders' meetings the board then changed the name of Piasecki Helicopter to Vertol (vertical take-off and landing) Aircraft Corporation and amended the bylaws to bar Piasecki's re-election as a director, on the grounds that he was running a rival company.  The company was acquired by Boeing in 1960 and renamed Boeing Vertol.  It became the Boeing Helicopter Division in 1987. 

The PV-2 was the second helicopter flown in the United States (following Igor Sikorsky's VS-300), and was designed and flown by Frank Piasecki in 1943. Piasecki designed and successfully sold a series of tandem rotor helicopters to the United States Navy, starting with the HRP-1 of 1944. The HRP-1 was nicknamed the "flying banana" because of the upward angle of the aft fuselage that ensured the large rotors did not hit each other in flight, and because the Coast Guard painted the aircraft yellow. The name would later be applied to other Piasecki helicopters of similar design. In 1949, Piasecki provided the H-21 Workhorse to the United States Air Force, an improved, all-metal derivative of the HRP-1. Piasecki's tandem-rotor helicopters flew higher than competing single rotor designs, and offered a smoother ride.

Source: Wikipedia