A perfect bird …

A light plane that is safe, accident proof and can be flown by anyone with minimum instruction has been a long time aviation dream and has been recognized, to an extent, by today’s ultra lights.

But the first — and perhaps the best — of such aircraft was built in 1943, and amazingly it was built in Germany as the country was collapsing under the weight of Allied and Soviet invasions. Even more amazingly, it was built by students in a technical high school as a class project.

The aircraft, the Winter LF 1 “Langsamflugzeug” (slow plane) “Zaunkönig” (Wren), was the brain child of Professor Dr. Ing. Hermann Winter, the designer of the Fiesler Storch, and his instructions to his students were to design a foolproof, single seat trainer that anyone could fly after one hour of ground instruction or five minutes of instruction if one had glider flying experience. In theory, after the “course,” the new pilot could hop in, start the engine, push the throttle forward and take off and fly around, and when they wanted to land, all they had to do was pull the throttle back to 40 mph and the plane would land in a sink that the gear could support.

The Wren was a parasol wing monoplane with long support struts that kept the wing out of the propeller wash and a tailplane that was set high for the same reason. It was small — a wingspan of slightly more than 26 feet and a little less than 20 feet long — and was powered by a Zündapp Z9-92 four-cylinder 51 horsepower engine driving a two blade propeller, and weighed more than 750 pounds. Like the Storch, the Wren had long, stalky fixed landing gear to absorb the shock of short field landings.

The aircraft had a wing loading of 8 pounds per square foot, and for slow flight, had fixed slats on the wing leading edge and wing flaps on the inboard trailing edges of the wing. The flaps dropped down to 40 degrees, and when the flaps dropped, the ailerons drooped 15 degrees so they were still able to control the aircraft.

With flaps down, the Wren could take off in 55 yards at an airspeed of 30 mph, and inflight proved very stable with harmonious controls that self centered when they were released. It could not be stalled. Below stall speeds, the rate of descent increased but never beyond the point of anything more than a hard landing. The ailerons were responsive at all speeds. The high parasol wing gave it excellent visibility in all directions.

Landing was quite easy. The approach speed was about 40 mph and touchdown about 35 mph. The rate of sink was easily checked, the long stroke landing gear fully absorbed the landing shock, and there was no swing after touchdown.
Because of the desperate war situation, at least one LF 1 was experimentally fitted with an over wing Panzerfaust, a recoilless anti-tank rocket launcher that was the ancestor of the RPG, but the Wren was never used in combat.

Several Wrens were built, and just before the end of the war, Dr. Winter flew one away from advancing Soviet forces and landed it behind American lines where he surrendered.

Two Wrens were shipped to the British Royal Aircraft Establishment at Farnborough for tests where they were flown by famous test pilot Eric “Winkle” Brown.

Brown found the little aircraft “delightful” and attempted to answer the question: “Was the Wren really capable of being flown with practically no instruction?”
To get the answer, Brown turned one of the Wrens over to one of the aerodynamicists by Royal Aircraft Establishment whom, while not quite a beginner (he had about two hours of instruction in a dual control trainer), was deemed a good test case. Brown said later, “I had not the slightest worry about his safety” and, as expected, the new “pilot” took off and landed without incident.

However, about 10 years after this test there was an event that serves as a reminder that the sky, like the sea, can be unforgiving and that nothing is perfect. On April 27, 1957, the famous Luftwaffe World War II ace (124 kills on the Western Front) Henrich “Heinz” Bär was doing test work for a light plane company at Braunschweig-Waggum and took a Zaunkönig for a flight. At low altitude, Bär attempted to put the aircraft into a spin to see if, in fact, it was impossible to spin. Sadly, the aircraft went into a flat spin and crashed before Bär could recover, and he was killed.

Today, the two Wrens sent to Farnborough still survive. Both had active post-war flying careers, and, at last report, one is in the Deutsches Museum collection at Oberschleissheim near Munich and the second is in the collection of the Internationals Luftfahrtmuseum Manfred Pflumm near Villingen-Schwenningen.

(For questions or comments, contact Dr. Michel at

marshall.michel@ramstein.af.mil.)