In February 1959 the Royal Canadian Navy took a decision that looked reckless: it would counter the nuclear submarine by flying anti-submarine helicopters not from carriers but from destroyer escorts, which are small, narrow and never still. Nobody had done it with a large helicopter. Trials began with a Sikorsky HO4S-3 on HMCS Buckingham in 1956 and continued with heavier machines on HMCS Ottawa, and the conclusion was that a pilot could not be relied upon to hold station over a heaving deck long enough to put the aircraft down.

The answer was to stop trying. A messenger line is passed from the helicopter to the deck and attached to a main cable; the cable is then hauled down under tension into a probe on the aircraft’s belly, pulling the helicopter to the deck and into a trap that clamps the probe. The device, redesigned by Fairey Aviation of Canada at Dartmouth next to Shearwater, was installed on HMCS Assiniboine in 1962 and 1963, tested with the new CH-124 Sea King from late 1963, judged successful in mid-1964 and entered Royal Canadian Navy service in April 1967.

It is called the Beartrap, and it is the single most influential thing Canadian naval aviation ever produced. Canadian crews earned the nickname Crazy Canucks for what they were prepared to do with it. The United States Navy, the Royal Navy, the Royal Australian Navy and the Japan Maritime Self-Defense Force all adopted it or a derivative; the American RAST system and the later TRIGON are descendants. Every frigate helicopter deck in the world is arranged around the problem Shearwater solved.

The first shipboard landing of a Sea King, on HMCS Assiniboine on 27 November 1963, is therefore a date that matters well beyond Canada. It is also why Shearwater survived unification, the loss of the carrier and the base closures of the 1990s: a navy that flies helicopters from small ships needs somewhere to train the crews.

The CH-124 was ordered as a modern machine and retired as a museum piece. The first of 41 was delivered in 1963 and the type stayed in service until 1 December 2018 — 55 years. Canada started looking for a replacement in 1985, when the Mulroney government began the New Shipborne Aircraft project; in 1987 it selected the EH101, and in 1991 the requirement was merged with a search and rescue helicopter project into a single buy of 50 aircraft costing 5.8 billion dollars.

That was the first failure and the most expensive. In 1993 the Campbell government cut the order to 28 anti-submarine and 15 search and rescue aircraft, bringing the cost down to 4.4 billion; in October 1993 the incoming Chretien government cancelled the whole thing, incurring roughly 500 million dollars in cancellation fees and leaving the Sea King with no successor at all. The second failure was the decision to split the replacement into two separate contracts for the helicopter and its mission system, which was reversed in 2002 when the procurement was put back together as the Maritime Helicopter Project.

The third was the competition itself. Tenders went out on 17 December 2003; the NH90 was eliminated as non-compliant; and in July 2004 Canada picked the Sikorsky S-92 derivative, designated CH-148 Cyclone, at 1.8 billion dollars for 28 aircraft with the first due in January 2009. The fourth failure was delivery. By September 2013 Sikorsky had accrued over 88 million dollars in late damages, and only interim-standard training aircraft existed. Six Block 1 aircraft were handed over on 19 June 2015 and initial operating capability came in June 2018, nine and a half years late.

Meanwhile the Sea King flew. It went to the Gulf in 1990 and 1991 and to the Adriatic, the Red Sea, Somalia and Haiti; it was maintained at a ratio of maintenance hours to flying hours that became a political scandal in itself; and fourteen of the 41 airframes were written off in accidents, with eight aircrew killed. 423 Squadron flew the last East Coast Sea King sortie from Shearwater on 26 January 2018, three aircraft in a flypast, and the type bowed out formally at Patricia Bay on 1 December 2018.

On 29 April 2020 CH-148 Cyclone 148822, call sign Stalker 22, was flying from HMCS Fredericton in the Ionian Sea off Greece during Operation Reassurance, the NATO deployment in eastern and southern Europe. The aircraft struck the water and all six people on board were killed: Sub-Lieutenant Abbigail Cowbrough, Sub-Lieutenant Matthew Pyke, Captain Brenden MacDonald, Captain Kevin Hagen, Captain Maxime Miron-Morin and Master Corporal Matthew Cousins. It was the worst single-day loss the Royal Canadian Air Force had suffered in decades.

The Flight Safety Investigation Report was released on 28 June 2021 and is precise about what happened. The pilot flew a left return-to-target turn at roughly 50 feet above the water and 130 knots, making an abrupt aft cyclic input that took the aircraft up to about 410 feet while the speed fell to 85 knots. The crew had not deselected the radar altitude hold and indicated airspeed hold flight director functions before the manoeuvre, although they had done so during an earlier demonstration of the same turn.

That combination produced what the investigation named the Command Model Attitude Bias Phenomenon: because the flight control laws are fly-by-wire, manually overriding the flight director while it remains engaged can leave the pilot without enough aft cyclic authority to correct the nose attitude. As the aircraft rolled wings level in a nose-down, accelerating attitude, the cyclic was pulled to the aft stop and the aircraft did not respond. The whole sequence, from the start of the turn to impact, took 14 seconds.

Brigadier-General John Alexander, the Director of Flight Safety, was explicit that the phenomenon had been unknown to the manufacturer, to the airworthiness authorities and to the aircrew before the accident. The fleet was paused and flying resumed on 16 June 2020 with restrictions; software and procedural changes followed. Sikorsky later settled with the families. Shearwater’s memorial to the six is on the wing it flew from, and the base community in Eastern Passage is small enough that most people there knew somebody on the aircraft.

Shearwater was a full airfield for eighty years, its two paved runways handling Trackers, Banshees, Argus patrol aircraft and every kind of visitor. The defence budget cuts of the mid-1990s stood CFB Shearwater down as a formation and folded its property into CFB Halifax, leaving 12 Wing as the flying organisation on the same site.

The runways went next. By 2002 only 10/28 was operational; in July 2007 it was reduced to its eastern end and 16H/34H reopened for helicopters only. The heliport formally opened on 31 July 2008 with a single 3,500-foot strip and four pads, and the old 16/34 was permanently closed and put outside the heliport fence. A visitor today sees a great deal of concrete that no longer leads anywhere, which is the visible record of a base that shrank without ever closing.

What did not shrink is the job. 423 Maritime Helicopter Squadron provides the Cyclone detachments that deploy in Maritime Forces Atlantic warships; 406 Maritime Operational Training Squadron trains every maritime helicopter aircrew in the Canadian Armed Forces; 12 Air Maintenance Squadron holds the deep maintenance; and the test and evaluation flight on the base does the work of turning a new mark of software into something a ship’s detachment can use. The Pacific squadron, 443, sits under 12 Wing from three time zones away.

The Shearwater Aviation Museum, founded in 1978 and reopened in a former gymnasium in August 1995 with an extension in August 2001, holds the Canadian maritime military aviation collection: a Fairey Swordfish, a Fairey Firefly, a CP-121 Tracker, a CF-101B Voodoo, two CT-133 Silver Stars and two Sea Kings donated by the Canadian Armed Forces in 2018. It also has a reconstructed briefing room from HMCS Bonaventure, which is as close as anyone gets now to the carrier navy.

At 10:31 on the night of 2 September 1998, Swissair Flight 111, an MD-11 bound from New York to Geneva, went into St Margarets Bay off Peggys Cove with 229 people aboard. Fishing boats from the surrounding villages were on the water within the hour. By the next day the mission had become a recovery, and Operation Persistence was the largest of its kind Canada had attempted.

More than 2,400 Canadian Armed Forces members took part, about 1,300 of them navy, 700 army and 400 air force, alongside roughly 450 RCMP officers and hundreds of Coast Guard staff. HMCS Preserver was the command ship; HMCS Moncton and HMCS Ville de Quebec worked the site; the submarine HMCS Okanagan located the flight data recorder, which was recovered on 6 September, with the cockpit voice recorder following on 11 September.

Shearwater was where it all came ashore. A temporary morgue was established on the base to receive human remains, and the wreckage was brought here for the reconstruction that eventually let the Transportation Safety Board explain what had happened to the aircraft’s in-flight entertainment wiring. Recovery work continued until December 1999. Ninety-eight per cent of the aircraft, more than 126,000 kilograms, was recovered, together with over 18,000 kilograms of cargo, and every one of the 229 people on board was identified.

It is not the sort of thing that appears in a wing’s mission statement, but for a great many Nova Scotians it is what Shearwater means. The base absorbed families, investigators, divers and press for more than a year, and Eastern Passage did the same.