The Vampire had proved the twin-boom, single-jet layout worked, but by the late 1940s it was running out of performance. De Havilland’s answer was not a clean-sheet design but a thorough reworking. The new thinner wing, with a modest leading-edge sweep on its inner section, delayed the drag rise of high-speed flight and let the aircraft fly faster and higher before compressibility bit. Under the skin went the de Havilland Ghost — a scaled-up development of the Goblin centrifugal turbojet, and notable in its own right as one of the first jet engines certified for civil airliner use, in the de Havilland Comet.

The pairing worked. Where the Vampire topped out around 540 mph, the Venom pushed past 600, with a markedly better climb and ceiling. It kept the Vampire’s virtues — light, simple, easy to build and maintain — while closing much of the gap to the swept-wing fighters just appearing. Officially the DH.112, the Venom was in many ways the Vampire finally allowed to reach its potential, and it became the bridge between de Havilland’s first jet and the jet age proper.

Turning a land-based night-fighter into a carrier aircraft is never trivial, and the Sea Venom shows why. The Royal Navy needed an all-weather jet that could find and attack targets in darkness or cloud, so de Havilland took the two-seat, radar-equipped NF layout and made it fit for the sea. The wings were given folding tips to fit carrier lifts and hangars; an arrester hook and a stronger, long-stroke undercarriage absorbed the punishment of deck landings; and the airframe was strengthened throughout for catapult launches.

The result, first flown in 1951, gave the Fleet Air Arm its first genuinely capable all-weather jet fighter. Sea Venoms flew strike missions during the 1956 Suez operation from British carriers, and the type served through the late 1950s and into the 1960s. Its influence spread abroad, too: France built a license version, the SNCASE Aquilon, for its own navy, and Australia operated Sea Venoms from shore and ship. The naval Venom is a neat example of how a single sound design could be adapted far beyond its original brief.

The Venom’s most remarkable career belonged to a country that never fired it in anger. Швейцария chose the type for its air force in the early 1950s and built it under licence at home, producing large numbers of the fighter-bomber variants. The straight-winged, docile Venom suited Swiss needs perfectly: it could operate from short Alpine airfields, was cheap and simple to maintain, and its rugged airframe stood up to decades of hard mountain flying.

Long after Britain, France and Australia had retired their Venoms, Switzerland kept flying. Its aircraft soldiered on through the 1960s and 1970s in the ground-attack and training roles, and only in 1983 did the Swiss Air Force finally withdraw the last examples — making them the last operational Venoms in the world. Many Swiss airframes survive today in museums and private hands, and it is thanks to Switzerland that the Venom remained a flying military aeroplane into the 1980s at all.

The Venom was a product of the early-1950s British and Swiss defence procurement systems, bought in bulk under government contracts and, in Switzerland’s case, license-built at home. Prices were quoted in 1950s pounds and francs that mean little today, and no consistent, verified flyaway unit cost circulates in modern sources. Any single dollar figure you see attached to a Venom should be treated as an estimate rather than a documented price.

There is likewise no credible published cost-per-flight-hour for the type. Operating-cost accounting of the kind kept for modern jets simply was not compiled — or has not survived in the open record — for a first-generation fighter retired decades ago. For the Venom, treat all precise cost numbers with caution.