Sikorsky CH - 124 Sea King The Sikorsky CH - 124 Sea King is a twin - engined anti - submarine warfare ( ASW ) helicopter designed for shipboard use by Canadian Naval forces , based on the US Navy ' s SH - 3 ( or S - 61 ) and has been continuously in service with the Royal Canadian Navy and Canadian Forces since 1963 . Design and development . The advent of nuclear - powered attack submarines in the late 1950s prompted RCN leaders to assess the new threat they posed . Although these craft were noisier than older submarines and could therefore be detected at longer ranges , they were also capable of while submerged , which was faster than the top speed of the RCN ' s new " St . Laurent " class destroyer s at . Some RCN leaders harbored serious doubts that the destroyers could effectively pursue and destroy such fast vessels , even when operating in pairs . During a 25 February 1959 meeting of the Naval Board , it was decided that the Navy would counter the new threat by outfitting destroyers for helicopter operation . The RCN had examined the feasibility of operating ASW helicopters from small escorts when it modified the " Prestonian " - class frigate in mid - 1956 with a temporary helicopter landing platform . Successful trials were held in October 1956 using a Sikorsky HO4S - 3 and a larger temporary landing platform was soon installed on the new destroyer escort . Operational trials were conducted using an RCAF Sikorsky S - 58 , a substantially larger and heavier aircraft than the HO4S , and the success of these tests led to approval of the concept . To achieve the goal , the RCN needed a helicopter capable of all - weather day - and - night operations with a heavy weapons load - capabilities the HO4S , the RCN ' s current utility helicopter , did not possess . Initial 1959 studies identified two helicopters that would meet the upcoming requirements - the Sikorsky S - 61 ( HSS - 2 ) and the Kaman K - 20 ( HU2K ) - but neither aircraft had flown at the time , so no choice was made . After further studies concluded that the smaller Kaman would better satisfy RCN requirements , the Treasury Board approved an initial procurement of 12 HU2K helicopters for $ 14 . 5 million in December 1960 . Despite this apparent setback for Sikorsky , several factors would derail the Kaman proposal . When the Naval Board held a follow - up meeting on 27 January 1961 to discuss the program , it was revealed that the asking price for the initial 12 units had nearly doubled to $ 23 million , a mere 6 weeks after the Treasury Board had approved the purchase . The Naval Board continued to endorse the HU2K , but some RCN leaders had serious misgivings due to the drastic price increase and staff reports that Kaman ' s performance projections might be overly optimistic . The Naval Board decided to await upcoming USN sea trials of the HU2K before rendering a final decision . The USN trials confirmed the calculations of RCN staff members ; the HU2K was substantially heavier than promised , hampering its flight performance and rendering it incapable of meeting RCN requirements , even if Kaman were to install a proposed upgraded engine . The Sea King was ultimately chosen for production on 20 December 1961 . The first of 41 helicopters would be delivered in 1963 carrying the designation CHSS - 2 Sea King . The airframe components were made by Sikorsky in Connecticut but most CHSS - 2s were assembled in Longueuil , Quebec by United Aircraft of Canada ( now Pratt & Whitney Canada ) , a subsidiary of Sikorsky ' s parent company . On 27 November 1963 , the new landing platform aboard HMCS " Assiniboine " ( DDH 234 ) was used for the first operational destroyer landing of a production CHSS - 2 . Upon the unification of Canada ’ s military in 1968 , the CHSS - 2 was re - designated CH - 124 . The RCN developed a technique for landing the huge helicopters on small ship decks , using a ' hauldown ' winch ( called a ' Beartrap ' ) , earning aircrews the nickname of ' Crazy Canucks ' . The ' Beartrap ' allows recovery of the Sea King in virtually any sea state . In 1968 , the RCN , Royal Canadian Air Force ( RCAF ) and Canadian Army unified to form the Canadian Forces ; air units were dispersed throughout the new force structure until Air Command ( AIRCOM ) was created in 1975 . In August 2011 , the Canadian Forces reverted to the former structure of the Royal Canadian Navy , Canadian Army and Royal Canadian Air Force . Operational service . The Sea King is assigned to " Iroquois " class ( 2 per ship with total of 6 ) destroyer s , " Halifax " class ( 1 per ship with total of 12 ) frigate s , and " Protecteur " class replenishment ships ( 3 per ship with total 6 ) as a means of extending the surveillance capabilities beyond the horizon . When deployed , the Sea King is accompanied by a number of crews - each with 2 pilots , a Tactical Coordinator ( TACCO ) , and an Airborne Electronic Sensor Operator ( AESOp ) . In order to find submarines , the Sea King ' s sonar uses a transducer ball at the end of a 450 - foot cable . It can also be fitted with FLIR ( Forward - Looking Infra - Red ) to find surface vessels at night . The CH - 124 has undergone numerous refits and upgrades , especially with regard to the electronics , main gearboxes and engines , surface - search radar , secure cargo and passenger carrying capabilities . Replacement . From 1983 onward attempts were made to replace the aging Sea King helicopters . Due to a series of financial and political issues , the process was hampered by repeated delays . In the end the CH - 148 Cyclone , a new version of the Sikorsky H - 92 Superhawk was selected .