An integral part of the Fleet Air Arm SAR story, the Westland Wessex was the mainstay of UK aerial SAR operations for many years, entering service with the Royal Navy in 1961 and serving until its final variant operated by the RN, the HU5, was withdrawn from service in 1988.
Whilst a very effective platform for Search and Rescue, the Wessex was actually the first helicopter operated by the Royal Navy to be designed from the outset as an anti-submarine platform. It was also the first helicopter in the world to be produced in significant numbers with a free gas turbine for an engine. The free gas turbine is effectively a jet engine where the exhaust gases revolve a turbine wheel, which in turn provides drive to the gearbox. This replaced the older piston engines which had powered previous helicopters.
The design features which made the Wessex such an effective anti-submarine helicopter were also highly desirable in a Search and Rescue helicopter. Fitted with an early automatic pilot system, the Wessex could operate in day or night and in all weathers. The Wessex was also quieter and less prone to vibration than piston-engine helicopters, qualities which were invaluable to the rear seat crews who were attempting to treat casualties. The load carrying capabilities of the Wessex were also a marked improvement on its predecessor, the Whirlwind, which allowed the Wessex to carry a greater number of casualties. Finally, the Wessex’s new Napier Gazelle engine allowed the aircraft to be started very quickly, enabling the crews to respond to emergency calls quicker than they had been able to do previously.
In the anti-submarine role, the Wessex was developed from the HAS1 (Helicopter Anti Submarine Mk1) into the HAS3, whose advances included a superior radar and avionics fit, a more powerful engine, a more advanced weapons system and improved navigation features. However, it was the HAS1 which continued to equip Fleet Air Arm SAR squadrons, as many of these modern and expensive technological advances were geared more towards Anti Submarine Warfare. The next step in the aircraft’s evolution was the Wessex HU5 (Helicopter Utility Mk 5) which was initially produced to meet the requirement for a battlefield transportation platform capable of moving Royal Marines from the decks of assault ships into action. The HU5 was adopted by the Royal Navy’s SAR force, entering service with 772 Naval Air Squadron in 1976 before 771 Naval Air Squadron followed suit in 1979.
The HU5 was the most capable version of the Wessex for Search and Rescue. It was powered by two Rolls Royce Gnome gas turbines, providing nearly double the power of the HAS1. This gave SAR crews an extra range of some 90 miles, hugely expanding the area of SAR cover which could be provided throughout the UK and out to sea. This extra power also gave more options to SAR crews in actually carrying out rescues, as this greater power margin allowed the helicopter to be operated in more challenging conditions.
The Wessex finally finished its long and distinguished service with the Royal Navy in 1988, being replaced in its Search and Rescue, anti-submarine and commando transport duties by the Sea King. Whilst perhaps best remembered for its roles in the Falklands War, the red and blue SAR Wessex saved countless lives across the UK for many years during its illustrious service career.