The Junkers G.38 had a wing two metres thick at the root. Junkers, being Junkers, looked at that volume and decided it was a waste to fill it with nothing but structure. So they put passengers in it.

On the second aircraft, six people sat inside the leading edge of the wing, out between the fuselage and the inner engines, with the view a modern airline passenger would sell a kidney for. Mechanics, meanwhile, could walk along a corridor inside the wing and service the engines in flight.

The thick-wing idea, taken seriously

Hugo Junkers had spent two decades arguing that the future was the flying wing — that eventually the whole aircraft would be lifting surface, and the fuselage would disappear. The G.38 is what that conviction looks like when it collides with 1929 engineering reality.

The wing is enormous, deep enough to stand up in near the root, and structurally the entire aeroplane. The fuselage is almost an afterthought hanging beneath it. It looks less like an airliner than like something a wing grew.

Contemporary engineers were not universally charmed by the wing seats. The German technical press, in a description translated for American readers in 1930, was politely unconvinced.

That is a useful corrective to the legend. The wing cabins were real, but the celebrated forward-facing panoramic glazing is best evidenced on the second machine, D-2500; the first aircraft’s wing cabins were lit from above, and the men who measured it thought the whole idea better suited to cargo.

A moving target

The G.38 was rebuilt almost continuously. It began with a mismatched set of four engines — two Junkers L55 V12s and two smaller L8s — and worked through several combinations before settling on Jumo diesels in 1934. Passenger capacity on the first aircraft went from 13 to 19 to 30 as the fuselage was rebuilt with two decks.

It also went to Britain. When D-2000 flew into Croydon in 1931 the newsreel cameras were waiting, and the commentary caught the only thing anybody cared about.

Two aircraft, two endings

Only two were built in Germany, though Mitsubishi licence-built six in Japan as the Ki-20 heavy bomber — a type so secret that most Japanese had no idea it existed.

The first German aircraft crashed at Dessau in 1936 during a test flight after maintenance. The test pilot, Wilhelm Zimmermann, survived, and nobody was killed. The second was taken over by the Luftwaffe in 1939 as a transport and was destroyed on the ground at Athens-Tatoi on 17 May 1941, in an RAF raid.

Nothing survives. What remains is the idea — that if you build a wing big enough, you may as well live in it — which resurfaces every time somebody draws a blended-wing-body airliner and is told it will never be certified.

British Pathe at Croydon, 1931:

Earlier Pathe coverage, with a Junkers A50 parked underneath the wing for scale:

And Junkers’ own film of the aircraft:

Sources: NACA Aircraft Circular No. 116, May 1930 (translation of Zeitschrift des Vereines deutscher Ingenieure, 4 January 1930); British Pathe archive; Bundesarchiv.