Kaman SH-2 Seasprite

SH-2 Seasprite
SH-2F Seasprite of the US Navy
Role	Anti-submarine warfare helicopter
Manufacturer	Kaman Aircraft Corporation
First flight	2 July 1959 (HU2K-1)
Introduction	December 1962
Retired	Retired by United States Navy in 1993
Primary users	United States Navy (historical) Royal New Zealand Air Force (historical)
Produced	1959-1969
Number built	184
Unit cost	SH-2F: US$16 million
Variants	Kaman SH-2G Super Seasprite

The Kaman SH-2 Seasprite is a ship-based helicopter originally developed in the late 1950s as a fast utility helicopter for the United States Navy. In the 1970s, anti-submarine, anti-surface threat capabilities were added to the design, including over-the-horizon targeting, resulting in modifying most existing UH-2 models to the SH-2 Seasprite.

This aircraft extends and increases shipboard sensor and weapon capabilities against several types of enemy threats, including submarines of all types, surface ships and patrol craft that may be armed with anti-ship missiles. It served with the U.S. Navy from the 1960s until the last SH-2G helicopters were retired in 2001.

In 1956, the U.S. Navy launched a competition to meet its requirement for a compact, all-weather multipurpose naval helicopter. Kaman's K-20 model was selected as the winner. Kaman was awarded a contract for four prototype and 12 production HU2K-1 helicopters in late 1957. Kaman's design was for a conventional helicopter powered by a single General Electric T58-8F turboshaft engine, driving a 44-foot four-bladed main rotor and a four-bladed tail rotor.

In 1960, the Royal Canadian Navy announced that the HU2K was the frontrunner for a large anti-submarine warfare contract; the Canadian Treasury Board had approved an initial procurement of 12 units for $14.5 million. Abruptly, Kaman raised the estimated price to $23 million, and there was concern that the manufacturer's weight and performance projections were overly optimistic. The Naval Board decided to wait until after the US Navy had conducted sea trials before approving the purchase. These trials revealed the HU2K to be overweight and underpowered, and thus incapable of meeting Canadian requirements. Hence, in late 1961, the Sikorsky Sea King was selected.