production following the completion of the delivery of 184 H-2s to the U.S. Navy. However, in 1971, production was restarted by Kaman in order to manufacture an improved variant of the helicopter, designated as the SH-2F. A significant factor in the reopening of the production line was that the Navy's Sikorsky SH-60 Sea Hawk, which was both newer and more capable in anti-submarine operations, had been determined to be too large to allow it to be safely operated from the smaller flight decks present upon the older frigates then in service. Further development Upon the enactment of the 1962 United States Tri-Service aircraft designation system, the HU2K-1 had been redesignated as the UH-2A, while the HU2K-1U model was redesignated as the UH-2B. During its service, the UH-2 Seasprite would be subject to several modifications and improvements, such as the addition of fixtures for the mounting of external stores. Beginning in 1968, the Navy's remaining UH-2s were extensively remanufactured; perhaps the most extensive alteration performance was the replacement of their original single-engine arrangement with a more powerful twin-engine configuration. In October 1970, the UH-2 was selected to be the platform to function as the interim Light Airborne Multi-Purpose System (LAMPS) helicopter. During the course of the 1960s, LAMPS had evolved out of an urgent requirement to develop a manned helicopter that would be capable of supporting a non-aviation vessel and serve as its tactical Anti-Submarine Warfare arm. Widely referred to as LAMPS Mark I, the advanced sensors, processors, and display capabilities aboard the helicopter enabled such equipped ships to extend their situational awareness beyond the line-of-sight limitations that unavoidably hampered the performance of shipboard radars, as well as the short distances involved in the acoustic detection and prosecution of underwater threats associated with hull-mounted sonars. Those H-2s that were reconfigured to perform the LAMPS mission were accordingly re-designated as SH-2Ds. On 16 March 1971, the first SH-2D LAMPS prototype conducted its first flight. Beginning in 1973, production deliveries of the latest variant of the rotorcraft, designated as the SH-2F, commenced. Amongst the features of the SH-2F model was the full suite of LAMPS I equipment, along with various other improvements, such as upgraded engines, an extended life main rotor, and an elevated take-off weight. During 1981, the Navy placed an order for 60 production SH-2Fs. From 1987 onwards, a total of 16 SH-2Fs were upgraded with a chin-mounted forward-looking infrared (FLIR)