Question: What German aircraft designed by Seiegfried and Walter Günter at Heinkel Flugzeugwerke in 1934 was operated by Lehrgeschwader 1?
Sentence (from "Albatros L 76"): As a result, it had to be improved, leading to the production of the Albatros L 77v, designed by Ernst Heinkel Flugzeugwerke.
Relevant evidence: No