The delta wing was a leap into the unknown. To carry a bulky early nuclear weapon fast and high, Avro’s team gambled on an all-wing triangle with no tailplane — a shape that offered enormous internal volume, a big fuel and bomb load, and a high service ceiling, but whose handling nobody yet understood. Rather than risk the full-size bomber, Avro built a family of scaled research gliders and jets, the Avro 707 series, to explore the delta’s low-speed and high-speed behaviour.

The production Vulcan refined the pure triangle with a kinked, cambered leading edge to tame buffet at height, and grew from the B.1 into the far more capable B.2, with a bigger wing, more powerful Olympus engines and a formidable electronic-warfare suite. The result was a bomber that looked like nothing else in the sky — and, thanks to that wing, could be flown with a lightness that astonished everyone who saw it displayed.

The howl is a product of the Vulcan’s intake design working at high power. At roughly 87–95% engine power, the B.2 draws around 100 kg of air per second through each intake — a square opening that narrows to an oval and then a round duct feeding the engine. That progressive constriction sets up a resonance, much like blowing across the neck of a bottle, and produces the distinctive rising howl. It is specific to the later 200-series airframe; the earlier B.1 did not sing the same way. For enthusiasts it became the single most beloved sound in British aviation.

The Vulcan was conceived as a high-altitude bomber, cruising above 50,000 ft where 1950s fighters and guns could not reach. That sanctuary vanished on 1 May 1960, when a Soviet SA-2 missile downed Gary Powers’ U-2 at high altitude. Suddenly height was a death sentence, not a shield. From the mid-1960s the V-force retrained for low-level penetration, threading below Soviet radar at a few hundred feet — a punishing regime that stressed the airframes and their crews far more than the high-level role they were designed for, and which changed the Vulcan’s paint from anti-flash white to disruptive camouflage.

The Vulcan was a state-funded Cold-War programme, never sold on an open market, so a clean modern flyaway price does not exist; period figures put each B.2 very roughly in the region of £750,000–£1 million in late-1950s money — an order-of-magnitude guide, not an audited number. The more revealing modern figures come from XH558: the Vulcan to the Sky Trust spent about £6.5 million returning it to flight by 2007, and keeping a single four-engined 1960s bomber airworthy cost on the order of £2 million a year — funded largely by public donations. When the specialist engineering support could no longer be guaranteed, no amount of money could keep it flying, and it was grounded in 2015.