Sikorsky S-55C helicopter at Palam Air Force Museum, Delhi

From the archive record

The Sikorsky S-55 helicopter being displayed at the Indian Air Force Museum in D The Sikorsky S-55 helicopter was a utility helicopter developed with company funds and without government sponsorship. Sikorsky designed and fabricated a mockup of an entirely new model with many novel features in less than one year. Its most significant novel features included unique placement of its piston engine and the incorporation of offset hinges in its main rotor head. Engine placement below and forward of the cockpit resulted in a large cabin directly below the main rotor and the rotor’s offset hinges provided large control moments to enable a wide center-of-gravity range. The result was achievement of nearly unrestricted placement of passengers or cargo in a relatively spacious cabin. Both of these