The Ar 68 belongs to the era of Germany’s clandestine rearmament. Under the Treaty of Versailles, Germany was forbidden a military air force, so the early Luftwaffe was developed in secret through the early 1930s, its aircraft cloaked in civilian or sporting pretexts, before Germany openly announced its air force in 1935.

The Ar 68 and the Heinkel He 51 were the fighters of this transition from covert to overt rearmament. They were the machines with which the reborn Luftwaffe first equipped its fighter units. That context matters: the Ar 68 was not just an aircraft but a symbol of Germany’s return to military aviation — and, being a biplane, a symbol of how quickly that first generation of equipment would be overtaken.

The Ar 68 was designed by Walter Rethel, Arado’s chief designer. His career carries a striking irony: after the Ar 68 he moved to the Bayerische Flugzeugwerke, where he worked alongside Willy Messerschmitt on the Bf 109 — the monoplane that made the Ar 68 and every other biplane fighter obsolete.

Rethel is thus a personal bridge between two ages of fighter design. The same engineering mind contributed to one of the Luftwaffe’s last biplane fighters and to the monoplane that swept it aside. It is a reminder that the transition from biplane to monoplane was not a change of people so much as a change of ideas — and that the men who built the old order often built the new one too.

The Ar 68 was powered by liquid-cooled inline V-12 engines, and it was built with two different ones. The earlier versions used the BMW VI, a capable but older design. The later and definitive versions used the Junkers Jumo 210, a more modern inverted-V engine that also powered early Bf 109s.

The engine made a real difference. The Jumo-powered Ar 68E, in particular, showed the type at its best, with noticeably improved climb and high-altitude performance — the areas in which the Ar 68 was often rated ahead of the He 51. The choice of a slim inline engine rather than a radial gave the aircraft its streamlined nose and the clean lines characteristic of German fighters of the period.

The Ar 68 and the He 51 were direct contemporaries, serving side by side as the reborn Luftwaffe’s first fighters. Comparisons between them were inevitable, and the Ar 68 generally came off well. It was widely regarded as the better fighter in several respects — notably in the climb and at altitude, especially in its Jumo-engined form.

The famous demonstration in which Ernst Udet is said to have flown the Ar 68 against the He 51 and preferred the Arado captures the general verdict, even if the details are best hedged. Both were sound, agreeable biplanes; but if the early Luftwaffe had a slightly superior first-generation fighter, it was arguably the Ar 68. The irony is that neither mattered for long: the Bf 109 made the whole comparison academic within a year or two.

By all accounts the Ar 68 was a delightful aircraft to fly — strong, stable and agreeable, with the honest, forgiving handling that made the best biplanes such rewarding machines. These qualities made it a capable fighter by the standards of its day and, later, an excellent trainer.

Its robustness was as valued as its handling. A good fighter-trainer has to withstand the rough treatment of pupils learning aerobatics and air combat, and the sturdy Ar 68 took it well. The combination of strength and sweet handling is a large part of why the type found such a useful second career teaching the Luftwaffe’s fighter pilots long after it had ceased to be a front-line aircraft.

One of the best-known stories about the Ar 68 concerns Ernst Udet, the flamboyant First World War ace and later senior Luftwaffe figure. In a comparative flying demonstration, Udet is said to have flown the Ar 68 against the He 51 and judged the Arado the superior fighter — a verdict that helped win it production orders.

As with many such anecdotes, the exact circumstances are told differently in different accounts, and it is sensible to treat the specifics with caution. But the story reflects a real and widely held judgement: the Ar 68 was a well-regarded fighter, thought by many to have the edge over the He 51. It duly entered Luftwaffe service as a front-line fighter — briefly, as it turned out.

The Ar 68 served as an operational Luftwaffe fighter for only a short period in the mid-to-late 1930s, and entirely in peacetime. Unlike the He 51, which was sent to Spain and saw combat with the Condor Legion, the Ar 68 was largely retained in Germany and saw little or no significant combat in the day-fighter role.

This is an important point of honesty. The Ar 68 was not a combat-proven fighter; its front-line career was brief, quiet and over before the Second World War began. Its significance rests not on a war record but on its place as an early Luftwaffe fighter, its reputation as a fine biplane, and the useful second life it went on to lead as a trainer and stop-gap night fighter.

The aircraft that ended the Ar 68’s front-line career was the Messerschmitt Bf 109. When Willy Messerschmitt’s all-metal, low-wing monoplane entered service from 1937, it made every biplane fighter in the world obsolete overnight. It was dramatically faster, climbed better and represented a complete generational leap.

The Luftwaffe re-equipped its fighter units with the Bf 109 as fast as production allowed, and the Ar 68 was quickly displaced. There is a personal thread here too: Walter Rethel, who designed the Ar 68, had moved to Messerschmitt and contributed to the Bf 109. The biplane was thus superseded, in part, by the work of its own designer — a fitting image for the speed and completeness of the monoplane revolution.

Pushed out of the front line, the Ar 68 found its most valuable role as an advanced fighter-trainer. Its strength and sweet handling made it ideal for teaching the fundamentals of fighter flying — aerobatics, formation, gunnery and air combat — to the pilots of the rapidly expanding Luftwaffe.

In this role the Ar 68 did some of its most important work. The pilots who would fly the Bf 109 in the opening battles of the Second World War were, in many cases, trained on the Arado biplane. There is a real continuity in that: the obsolete fighter helped forge the men who flew the aircraft that replaced it. For a type with so brief a combat career, this training contribution was arguably its most lasting legacy.

The Ar 68 had one last, more warlike, part to play. In the opening period of the Second World War, before purpose-built night fighters were available in quantity, the Luftwaffe pressed the obsolete biplane into service as an improvised night fighter. In 1939 and into 1940, Ar 68s flew some of the Luftwaffe’s earliest night-fighting patrols.

It was very much a stop-gap. The Ar 68 was not designed for the role and was quickly replaced as dedicated night fighters arrived. But it earns the type a small footnote in the early history of German night air defence — a last operational flourish for a fighter that had been overtaken by events years before. It is a modest distinction, but a genuine one.

In its construction the Ar 68 was conventional for its day: a single-bay biplane with a fuselage of welded steel tube covered in fabric, and wings of wooden structure, likewise fabric-covered over much of their area. It was a robust, straightforward airframe, well suited to hard use in both the fighter and, later, the training role.

Its armament was typical of the early 1930s fighter — a pair of rifle-calibre machine guns firing forward through the propeller arc. This was adequate against the aircraft of the mid-1930s but was already becoming light by the standards of the coming war, another sign of how quickly fighter design was advancing. The Ar 68 was a sound example of the fully developed biplane fighter, arriving just as that whole category was about to be rendered obsolete.

Unlike some of its contemporaries, which sold widely abroad, the Ar 68 was essentially a German aircraft. It was not a significant export success, and it served overwhelmingly with the Luftwaffe rather than with foreign air forces. This was partly a matter of timing — by the time it might have been marketed abroad, the biplane fighter was already being overtaken by the monoplane.

The result is that the Ar 68’s story is almost entirely a German one, tied to the specific circumstances of the reborn Luftwaffe. It equipped Germany’s early fighter units, trained Germany’s fighter pilots and flew Germany’s first improvised night-fighter patrols — but it did little of note beyond German service. That focus makes it a very pure example of a national first-generation fighter, produced for one air force at one particular moment.

The Ar 68 was produced in several versions, distinguished mainly by their engines and detail equipment. The Ar 68F used the older BMW VI engine; the Ar 68E, generally considered the definitive and best version, used the more modern Junkers Jumo 210 and offered improved climb and altitude performance. Later sub-variants included the Ar 68G and the experimental Ar 68H, which trialled features such as an enclosed cockpit.

Across all versions, production totalled something over five hundred aircraft, essentially all for the Luftwaffe. The differences between the variants were incremental rather than radical — the Ar 68 was a fully mature biplane design, refined in detail rather than transformed, right up to the point where the whole biplane concept was superseded.

As with most military aircraft of the 1930s, there is no reliable, transparent public figure for the Ar 68’s unit cost, cost per flight hour or total programme cost. It was procured through Luftwaffe contracts during the rapid, secretive expansion of German air power in the mid-1930s, and consistent lifetime cost data does not survive in a usable form.

Rather than repeat an invented number, we list the cost fields here as “not reliably recorded.” What can be said is that the Ar 68 was a conventional biplane of mixed wood-and-steel construction, and as such would have been comparatively economical to build and maintain by the standards of the day — one reason it remained useful as a trainer long after it had ceased to be a front-line fighter.

The Ar 68’s central misfortune was timing. It was a fully developed, high-quality biplane fighter that entered service in the mid-1930s — the exact moment when the all-metal monoplane fighter was arriving. The Messerschmitt Bf 109, entering service from 1937, was faster, climbed better and was comprehensively more modern.

This is the recurring story of the mid-1930s fighter: aircraft like the Ar 68, the Heinkel He 51, the British Gloster Gladiator and the Italian Fiat CR.32 were superb biplanes that arrived just as the biplane itself was being made obsolete. The Ar 68 was among the best of them, but that only meant it was an excellent example of a category with no future. Its rapid eclipse says less about the aeroplane than about the extraordinary speed of aeronautical progress in that decade.

The Arado Ar 68 is a rare and elusive type today. Few complete original examples are known to survive, and no widely documented airworthy original is generally recognised. Like many early Luftwaffe aircraft, the great majority were worn out in training service or lost in the war, and preservation was not a priority.

This scarcity is part of what makes the Ar 68 comparatively little known compared with the monoplane fighters that followed. It is remembered chiefly through photographs and records rather than surviving aircraft. Any claim of a surviving original should be treated with caution and hedged honestly — the safest statement is that the Ar 68 is very rare, and that this profile rests on the documentary record rather than on preserved airframes.