Sea trials for Flying Bananas. Data for the first one. XM-8 is 111832, whereas XM-9 and XM-6 are HRP-1s - note the different nose shapes. Photo dated May 1951 by Life but we gather that this took place off Key West in 1952. Photo by: Hank Walker / Life

The real Flying Banana - the HRP-1, still with an appropriately-shaped nose. 111813 was assigned to NACA in 1951. The airborne helicopter is 111820. Photo from: National Archives at College Park, Maryland

The Piasecki PV-17 or HRP-2 was developed from the original Flying Banana, the PV-3 or HRP-1. With a new nose and all-metal fuselage it was very similar to the later H-21. Only five HRP-2s were built. Three of these served with the HMX-1 experimental helicopter squadron based at Quantico, Virginia, from 1950 to 1953, before going to the US Coast Guard. Note the early Neptune.