The Ventura was the third in a line of military twins that Lockheed derived from its civil airliners. The Model 14 Super Electra gave rise to the Hudson, a maritime reconnaissance and light bomber that Britain bought in large numbers from 1938. As the war deepened, the RAF wanted a bigger, more capable successor with more power, more range and a heavier load.

Lockheed answered by developing a new military aircraft from its larger Model 18 Lodestar airliner. The result, the Ventura, was clearly of the same family as the Hudson but substantially bigger and more powerful. In effect the Ventura was the Hudson’s big brother — a natural evolution of a proven concept, scaled up for a more demanding war.

Like the Hudson before it, the Ventura began as a British order rather than an American requirement. Britain, buying American aircraft to supplement its own industry, placed the order in 1940, and Lockheed built the aircraft through its Vega subsidiary. The early Venturas went to the RAF, which named and operated them as bombers.

This British-order origin shaped the aircraft’s whole early career. It was designed to a bomber specification and delivered as a bomber, which is why it was first used in a role that turned out not to suit it. Only later, when the United States entered the war and the US Navy took an interest, was the type developed in the maritime-patrol direction where its real strengths lay.

The RAF introduced the Ventura to Bomber Command in late 1942 and used it for daylight raids on targets in occupied Europe. It was not suited to the task. Though fast for a patrol aircraft, it was still a large, relatively unmanoeuvrable twin, and over the well-defended coast of the Low Countries it was highly vulnerable to modern German fighters and flak.

Crews were unimpressed, and the aircraft acquired the unflattering nickname the “Flying Pig”. Losses on daylight operations were heavy relative to the results achieved, and it quickly became clear that sending the Ventura against defended land targets in daylight was a costly mistake. The daylight-bomber experiment was a genuine failure — but it was not the end of the story.

The nadir of the Ventura’s bomber career came on 3 May 1943. Twelve Venturas of No. 487 Squadron RNZAF were sent to attack a power station in Amsterdam in daylight. The raid met overwhelming fighter opposition, and eleven of the twelve aircraft were shot down — only one, damaged, turned back. It was one of the most one-sided losses suffered by any RAF squadron in a single operation.

Leading the attack was Squadron Leader Leonard Trent, who pressed on against hopeless odds until his own aircraft was destroyed and he was taken prisoner. The full story emerged only after the war, from survivors returning from captivity, and Trent was awarded the Victoria Cross — recognition of extraordinary determination in the face of certain destruction. The Amsterdam raid is remembered both for that valour and as the clearest possible proof that the Ventura had no future as a daylight bomber.

Withdrawn from the daylight-bomber role, the Ventura was redirected to the work it was genuinely good at: maritime patrol and anti-submarine warfare. Here its qualities came into their own. It had the range and endurance to patrol far out over the sea, the load-carrying ability to haul a useful mix of bombs, depth charges and guns, and enough speed to reach a contact quickly and press an attack.

RAF Coastal Command and Commonwealth air forces used it to watch the ocean approaches and hunt U-boats, flying the long, monotonous, occasionally deadly patrols on which the Battle of the Atlantic and the war against enemy shipping depended. In this role the “Flying Pig” became a respected and effective aircraft — a reminder that an aircraft’s worth depends entirely on matching it to the right job.

It was the United States Navy that made the most of the design. The Navy adopted the Ventura as the PV-1, a dedicated patrol bomber, and operated it widely. PV-1s flew anti-submarine and patrol missions in the Atlantic and, above all, ranged across the Pacific, where their speed, range and firepower suited the vast distances of the theatre.

Among the PV-1’s hardest postings was the Aleutian Islands, the cold, fogbound chain stretching toward Japan. From Aleutian bases, PV-1s flew bombing and patrol missions against Japanese positions in the Kuril Islands — some of the few land attacks on the Japanese home islands’ approaches — in appalling weather that was often as dangerous as the enemy. The PV-1 was the version in which the Ventura truly proved its value.

Building on PV-1 experience, Lockheed developed a substantially improved version for the US Navy: the PV-2 Harpoon. It introduced a larger wing with greater fuel capacity for longer range and endurance, a strengthened structure and heavier armament, turning the Ventura into a purpose-designed long-range patrol bomber rather than an adapted one.

The Harpoon entered service in the later part of the war and continued in use afterwards. Its extra range and load made it a genuinely capable ocean-patrol aircraft, and it is the version in which the Ventura line reached maturity. Several PV-2s survive today, some airworthy, making the Harpoon the best-remembered member of the family.

Much of the Ventura’s capability came from its engines. It was powered by two Pratt & Whitney R-2800 Double Wasp eighteen-cylinder radials — the same superb, powerful engine family that powered the F4U Corsair, P-47 Thunderbolt and many other first-rank American aircraft — each producing on the order of 2,000 horsepower.

That was a great deal of power for a patrol aircraft, and it gave the Ventura a high top speed for its class, good load-carrying ability and the performance to reach and attack contacts quickly. The R-2800 was also famously rugged and reliable, exactly what was wanted for long over-water patrols far from help. If the airframe was ordered for the wrong role, the engines were never in doubt: they were among the best in the world.

The Pacific was where the Ventura and Harpoon did much of their most important work. US Navy PV-1s and PV-2s flew patrol, anti-shipping and bombing missions across the theatre’s enormous distances, and the Royal New Zealand Air Force made the Ventura its principal bomber and patrol type in the South and South-West Pacific, operating it intensively against Japanese-held islands.

The Aleutian campaign was a theatre of its own. From bases in the fogbound, storm-lashed Aleutian chain, PV-1s carried out long, gruelling missions against Japanese positions in the Kurils, in some of the worst flying weather anywhere in the war. It was cold, isolated, dangerous work, and the Ventura’s range, ruggedness and twin-engine reliability were exactly what such conditions demanded.

The Ventura family carried a confusing array of designations reflecting its many customers. The RAF flew the Ventura Mk I and Mk II as bombers. The US Army Air Forces took a number as the B-34 Lexington and the reconnaissance B-37, though it made relatively little use of them. The really important military versions were the US Navy’s: the PV-1 Ventura patrol bomber, and the improved PV-2 Harpoon.

The PV-2 Harpoon was the most developed member of the family, with a larger wing, greater fuel capacity and range, a strengthened airframe and heavier armament. Where the earlier aircraft were adaptations of a bomber ordered for another role, the Harpoon was in effect a purpose-built long-range patrol bomber — the version in which the design reached its full potential, and the one from which most survivors come.

As with most American wartime aircraft supplied through Lend-Lease and wartime procurement, the Ventura has no clean, reliable public figure for unit cost, cost per flight hour or total programme cost. It was bought and transferred through complex government arrangements rather than sold at a transparent list price, and consistent figures across its many variants and operators are not available. Any single dollar figure quoted for it should be treated with caution.

In general terms, the Ventura was a substantial, twin-Double-Wasp aircraft — more expensive to build and operate than a small single-engined type, but a conventional mass-produced machine using well-established engines and structures. Built in the low thousands and operated by many air forces, it was economical enough to field widely. We list its cost fields as “not reliably recorded” rather than invent numbers.

Few patrol aircraft of the war served under so many flags. Besides the US Navy and USAAF, the Ventura was flown by the RAF and by the Royal Canadian, Australian, New Zealand and South African air forces, each using it for bombing or, more successfully, for maritime patrol and anti-submarine work. New Zealand in particular relied on it heavily in the Pacific.

Brazil operated PV-1s and PV-2s on anti-submarine patrol in the South Atlantic, an important and often overlooked theatre of the U-boat war, and kept them in service afterwards. Other nations, including the Netherlands, France and Portugal, flew the type as well; Portugal’s PV-2 Harpoons served on maritime patrol into the 1970s. This breadth of service is a large part of the Ventura’s significance: it was one of the workhorse patrol aircraft of the entire Allied war at sea.

Unlike some wartime types, the Ventura and especially the PV-2 Harpoon left a reasonable number of survivors, helped by long post-war service and by civilian use after the war (some Harpoons flew for years as fire-bombers and executive transports). Several PV-2s survive in museums today, and a small number remain airworthy — making the Harpoon one of the more accessible surviving members of the family, though genuine flying examples are rare and precious.

The type’s post-war career stretched surprisingly long in some air forces: Brazil, Portugal and others kept Venturas and Harpoons on maritime patrol into the 1950s, 1960s and, in Portugal’s case, the 1970s. For an aircraft that began as a British bomber order in 1940, a working life stretching over three decades was a remarkable second act — and a fitting one for a design that only truly succeeded once it found the right role.