The three-man Westland Whirlwind helicopter was a British-built version of the US Sikorsky S-55.

In its early incarnations (HAR1, 3 and 5) the aircraft served in non-combat roles, including search and rescue and communications functions.

It was to become the first British helicopter designed for anti-submarine work in the front-line when the HAS 7 come on the scene in 1956. It was equipped with radar and dipping Asdic for submarine detection and strike weapons.

The first operational squadron for these more advanced anti-submarine Whirlwinds was No.845 in August 1957, although the initial HAS 7s were delivered to No.700 earlier that year.

Two years later the HAS 7s were withdrawn from service for modifications for some months before returning back to operation in No.s 815. From that point, the Whirlwind began to replace the Gannet in anti-submarine squadrons.

The first appearance on the British stage for the Whirlwind was in 1952 when the American-built HAR 21 and HAS 22 Sikorsky S-55s led the way, but then the first prototype British Whirlwind HAR 1 flew in August 1953.

The initial ten HAR 1 in the Fleet Air Arm went into service with 705 Squadron. These were then followed by the HAR 3 which had a larger 700hp Wright Cyclone R-1300-3 engine than the 600hp Pratt & Whitney Wasp R-1340-40. It was not until 1955 that the HAR 5 flew for the first time with a British power plant, the Alvis Leonides Major.

In its last HAS 7 version this engine was a 750hp Alvis Leonides Major 755/1. This helicopter had a hovering ceiling at 9,400ft and a range of 334 miles at 86mph. Its top speed of 109.5mph could be achieved at sea level. In length the helicopter was 41ft 8.5in, height 15ft 4.5in and with a rotor diameter of 53ft.

The Whirlwind operated from 814, 815, 820, 824, 845, 847 and 848 Squadrons and was part of 705 and 771 Training Squadrons.

The aircraft was to be found in its search and rescue role at Brawdy, Culdrose, Lossiemouth and Yeovilton.

From its start with the Navy, the Whirlwind came to be used by all three Services.

(Featured in Navy News August 2002)