The two American heavies split the work of the daylight bombing campaign, and crews argued their merits for eighty years. The B-24 was faster (cruising around 215 mph against the B-17’s 182), flew farther, and carried more bombs — roughly 2,100 miles with a 5,000 lb load, where a B-17 managed about 2,000 miles with 4,000 lb. That reach made the Liberator the natural choice for the Pacific’s vast distances and for ocean patrol.

El B-17, though, was easier and more forgiving to fly, held formation better at high altitude, and earned a legend for absorbing battle damage and still coming home. The Liberator’s shoulder wing and big roller-shutter bomb-bay doors made it more fragile under fire and lethal in a water landing. Both were vital; the honest verdict is that they were complementary tools, and the B-24’s trump card was that it could be built in numbers no other heavy bomber ever matched.

The Davis wing was a high-aspect-ratio aerofoil that David R. Davis pitched to Consolidated with striking efficiency claims. Wind-tunnel tests bore much of it out: the long, slender wing produced excellent lift-to-drag, and it handed the Liberator the cruise speed, ceiling and range that set it apart. It is why the B-24 could reach targets a B-17 could not, and why it excelled over the wide oceans.

But the same wing had to be mounted on the shoulder of a deep fuselage to clear the bomb bay, which raised the aircraft’s centre of gravity relative to the wing, made it heavy and tiring on the controls, and gave little margin if an engine failed on take-off. Laden and battle-damaged, a Liberator was less able to stagger home than a Fortress — and its shutter-type bomb doors flooded a ditched aircraft in seconds. The Davis wing was a brilliant bet on efficiency that crews paid for in workload and fragility.

Building a four-engine bomber like a car was a genuinely radical idea. Ford broke the Liberator into thousands of sub-assemblies and built a purpose-made factory at Willow Run, near Ypsilanti, Michigan — a single structure so long its final assembly line turned 90 degrees to stay within the county line. Early on the plant struggled; sceptics called it “Will-it-Run.” Once the tooling settled, it became the icon of American war production, employing tens of thousands, many of them women — the real “Rosie the Riveters” — and at its 1944 peak completing a B-24 roughly every 63 minutes. Combined with Consolidated, Douglas and North American lines, the consortium built more than 18,000 Liberators, a total no other American military aircraft has ever approached.

Like most wartime aircraft, the Liberator had no meaningful “cost per flight hour” in the modern sense — it was a war material produced at national scale, not a leased asset. What is well documented is how sharply its unit cost fell as the assembly lines matured: a B-24 that cost far more early in the programme was being delivered for around $297,000 by 1944 as Willow Run and the other plants hit stride. That collapse in cost per airframe — the direct dividend of building a bomber an hour — was as important to the Allied war effort as any single performance number.