In early October 1916, evaluation of Fokker's M.21 prototype at Adlershof revealed poor construction and workmanship. In response, "Idflieg" directed that a production D.III be tested for quality control purposes. In November 1916, serial 369/16 was disassembled and tested to destruction at Adlershof. While the wings proved acceptable, the fuselage and tail surfaces failed to meet specifications. "Idflieg" reprimanded Fokker for his firm's substandard construction practices, but permitted D.III production to continue. The "Kogenluft", however, forbade the use of Fokker aircraft for frontline duties.