World War II Database

Contributor: Alan Chanter

ww2dbaseDeveloped in parallel with the company's Ar 67, the Ar 68 would become Germany's last biplane fighter, and entered service in the summer of 1936 as a successor to the Heinkel He 51. The first prototype, the Ar 68a, had a BMW VId engine rated at 750 h.p. for one minute at sea level. It flew for the first time in the summer of 1934 but was found to have a somewhat disappointing performance. This deficiency was partially overcome with the second and third prototypes, Ar 68b and Ar 68c, which differed primarily in employing the Junkers Jumo 210A 12-cylinder inverted vee liquid cooled engine rated at 680 h.p. at take off. Trials with the Ar 68b revealed that the drag of the Jumo 210's chin radiator depressed the performance potential, and a redesigned unit was therefore developed and installed in the Ar 68c. This aircraft, which was also armed with two fixed forward firing 7.92 mm MG 17 machine guns with 500 r.p.g., made its maiden flight in the summer of 1935 and with the Jumo engine providing not only greater power and therefore performance, but also an improved the forward field of vision from the cockpit, was found satisfactory for serial production. Two further aircraft, the Ar 68d and Ar 68e (respectively powered by the BMW VI and Jumo 210Da engines), were built as pre-production prototypes.

ww2dbaseThe Ar 68 was typical of late-generation biplane fighters in its clean design, comparatively high-powered engine and cantilever main landing gear units. The aircraft had an oval-section fuselage of steel tube construction with light alloy panels covering the rear decking and forward sections, while the rest of the fuselage was covered with fabric. The single-bay wings were of wooden construction under a covering of plywood and fabric. The distinctive shaping of the vertical tail surface, which was to be used almost without exception on subsequent single-engine designs from the Arado stable, was introduced on the Ar 68.

ww2dbaseInitially it had been planned that the Jumo 210 engine should be the desired powerplant for production Ar 68s, but delays in its manufacture meant that the first deliveries, in the summer of 1936, were of an interim model (Ar 68F-1 of which 120 were built) with the 750 h.p. BMW VI 7.3z engine. Later in 1936, supplies of the Jumo 210Da (subsequently replaced by the almost identically rated Jumo 210 Ea) engine had reached the point at which manufacture and delivery of the Ar 68E-1 (375 built) became feasible, and this model began to enter Luftwaffe service in the spring of 1937. Two Ar 68s would, in 1938, be posted to the Condor Legion in Spain to undergo operational evaluation.

ww2dbaseThe Ar 68 survived in first-line Luftwaffe service only until 1938, by which time it had been superseded by the Messerschmitt Bf 109. At the start of World War II the type was serving only in an interim night fighter role, and by the spring of 1940 was relegated to the advanced flying and fighter lead-in training roles only.

ww2dbaseTwo further variants should be mentioned. The Ar 68g designation was reserved for an unbuilt model with a supercharged BMW engine, and the Ar 68h was a single factory prototype powered by an 850 hp supercharged BMW 132 nine-cylinder radial engine (a licence built version of the American Pratt & Whitney Hornet) which gave a 65 km/h increase in maximum speed. The Ar68h was provided with an enclosed cockpit with a rearward-sliding canopy, and its firepower was enhanced with the addition of a pair of 7.92mm machines guns in the upper wing.

SPECIFICATIONS

Ar 68

Machinery	Junkers Jumo 210ea 12-cyl vee engine rated at 690hp
Armament	2x7.92mm fixed forward firing machine guns in the upper side of the forward fuselage, 60kg external bomb load
Crew	1
Span	11.58 m
Length	9.50 m
Height	3.28 m
Wing Area	27.30 m²
Weight, Empty	1,840 kg
Weight, Loaded	2,475 kg
Speed, Maximum	335 km/h
Service Ceiling	8,100 m
Range, Normal	415 km

Photographs