Photos: A century of helicopters

If the Coast Guard helicopter on the ground here reminds you of a certain tropical fruit, you're not alone: this Piasecki HRP-1 twin-rotor aircraft was widely known as the "flying banana." (Piasecki employees referred to its precursor, which first appeared in 1945, as a "dogship.") There were several advantages to the tandem design--it was easier to control this design than one with a single rotor, the additional lift meant more people and more cargo could be carried, and weight distribution was less of an issue. The fuselage was curved so that the rear rotor was higher than the forward one, to prevent the blades from colliding.

The HRP-1, with its 600-horsepower engine, could ferry 10 passengers and 2 crew members, carry a load of more than 1,800 pounds, and cruise at 86 miles per hour. Its range was 265 miles, and its ceiling with a normal load was just over 10,000 feet. In use with the Marine Corps as well as the Coast Guard, it performed functions including search and rescue, heavy transport and antisubmarine warfare.

This picture, from May 1950, also shows a two-person Sikorsky HO3S-1G "Dragonfly" in flight.