CH-124 Sea King

The Sea King entered service with the Royal Canadian Navy (RCN) in 1963 as an all-weather shipborne helicopter to provide close antisubmarine warfare (ASW) protection for ships at sea. By the time it was retired from service 55 years later, in 2018, it had undergone a variety of modifications and role-changes. Throughout, it maintained its well-earned reputation as the workhorse of the fleet. Sea King helicopters were a critical element in nearly every naval operation at home and abroad.

The Sea King entered service with the Royal Canadian Navy (RCN) in 1963 as an all-weather shipborne helicopter to provide close antisubmarine warfare (ASW) protection for ships at sea. By the time it was retired from service 55 years later, in 2018, it had undergone a variety of modifications and role-changes. Throughout, it maintained its well-earned reputation as the workhorse of the fleet. Sea King helicopters were a critical element in nearly every naval operation at home and abroad.


Sea King Helicopters

Sea King Helicopter

In the late-1950s, faced with the problem of nuclear-powered Soviet submarines that could outrun surface warships, the RCN determined that the best response was aircraft. In the 1950s, the navy acquired the fixed-wing CS2F Grumman Tracker to fly off the aircraft carrier HMCS Bonaventure. It also explored the idea of modifying its St Laurent-class destroyers to embark a helicopter and eventually settled on a Canadian version of the United States Navy’s (USN) Sikorsky HSS-2/SH-3 Sea King, which replaced the navy’s fleet of Sikorsky HO4S-3 helicopters.

Design

The RCN purchased a total of 41 Sea King helicopters, designated the CHSS-2. (It was renamed the CH-124 after unification of the armed forces in 1968.) The components were made by Sikorsky in the United States for assembly at its Canadian subsidiary, United Aircraft Canada Limited (now Pratt & Whitney Canada) in Longueuil, Quebec.

The Sea King’s large size and twin turbo-shaft jet engines allowed for a much larger payload than earlier ASW rotary-wing aircraft, which were generally single-engine designs. A fold-up rotor and tail enabled the helicopter to fit in confined spaces. It had a maximum speed of 165 mph (267 km/h) and a range of nearly 400 miles (625 km). Initially, the primary antisubmarine sensor was a tethered (dipping) active sonar. The helicopter also carried two antisubmarine torpedoes.

While most other navies only operated such large helicopters from aircraft carriers, the RCN embarked the Sea Kings on their helicopter-carrying destroyers (DDH). To do so, they developed the “beartrap” hauldown system, which allowed the helicopter to land safely and quickly, even on a rolling deck.

Sea King and Beartrap
Did you know?

The “beartrap” was a Canadian innovation designed to enable the safe operation of helicopters from “small” decks pitching and rolling in extreme sea states. Built by Fairey Aviation in Dartmouth, Nova Scotia, it is formally called the “helicopter hauldown and rapid securing device” (HHRSD). The “beartrap” revolutionized maritime helicopter operations and was adopted by several allied navies, including the US, Australia and Japan.


Modifications

As naval operations evolved, the Sea Kings received a variety of upgrades and modifications from the baseline CH-124 airframe. Beginning in the mid-1980s, the dipping sonars were progressively removed from some aircraft to be replaced by an onboard passive sonar processor and sonobuoys.

In the summer of 1990, six Sea Kings were hastily converted to a surface surveillance configuration for the Persian Gulf War. The dipping sonar was replaced by a variety of equipment, including a forward-looking infrared (FLIR) device, chaff and flare dispensers, a missile approach warning system, a door-mounted light machine gun, and aircrew-seat armour. These modifications were later incorporated across the fleet.

Helicopter Trials, 1963

Service

The first Sea Kings were taken on strength on 24 May 1963; the first landing using the beartrap at sea was on HMCS Assiniboine (DDH-234) on 27 November 1963. Besides the aircraft carrier and St Laurent class, Sea King helicopter air detachments were embarked in all the subsequent Iroquois-class destroyers (two per ship), Halifax-class frigates (one per ship), and fleet replenishment ships (two to three per ship, with enhanced onboard maintenance facilities). With the introduction of the Sikorsky CH-148 Cyclone, the last Sea King was retired on 1 December 2018.

Besides purely naval operations, the versatile Sea King also participated in search and rescue missions, disaster relief, counter-drug operations, international peacekeeping, counter-piracy, pollution and fisheries patrols, and personnel transportation for fighting forest fires.

Between 1963 and 2018, fourteen Sea Kings were lost, and eight aircrew killed in accidents. However, its safety record improved over the years, due to a combination of “lessons learned,” improved maintenance support and the dedication of the maintenance crews.

Sea King helicopters were a critical element in nearly every naval operation at home and abroad. With more than five decades of service, the Sea King was the longest-serving aircraft in the CAF inventory. It was often joked that the helicopter was older than the pilots who flew it. After their retirement from service, several examples were retained for various museums and monuments.

Did you know?
During its service, the Sea King fleet flew more than 550,000 hours. At its normal cruising speed, this is roughly equivalent to flying 7,200 times around the Earth or from Earth to Mars.