Professor Hugo Junkers (1859-1935) became convinced that all metal structure was the ultimate answer to successful aircraft design, he produced the experimental J.1 “Blechesel” (Tin Donkey) to exemplify his 1910 patent for a cantilever all-metal wing.
An all-metal semi-cantilever biplane, the multi-spar metal wings were covered with corrugated light alloy sheet. The entire forward part of the fuselage to the rear of the cockpits was made of 5 mm sheet steel armour. The front fuselage alone weighed 1030 lb. The rear fuselage was a light alloy tube structure, covered with fabric on most aircraft. Control surfaces were all metal, with ailerons on the top wing only.
The J.1 first flew on December 12, 1915, giving unexpectedly stable performance.
Altogether, 227 J.1 were built, serving from late 1917 until the end of the war.
Engine: Benz Bz.IV, 200 hp
Wingspan: 52 ft 6 in
Wing area: 531.5 sq.ft
Length: 29 ft 10.5 in
Height: 11 ft 1.75 in
Empty weight: 3895 lb
MTOW: 4797 lb
Max speed: 97 mph at SL
Endurance: 2 hr
Armament: 1 x Parabellum mg
All Aero 