In the United Kingdom, a different training system was used, although it too started out with obsolete aircraft before the Avro 504 and Airco DH.6 became the primary trainers, supplemented until the end of the First World War with obsolete combat aircraft for advanced training. To train the many potential aviators coming from Canada and the US, the Royal Flying Corps Canada was set up, operating Curtiss JN-4 (Can) trainers until the United States began its own training program, using Curtiss JN-4s and Standard J-1s. In Germany, various obsolete two seaters were produced for training purposes, the most numerous being the Albatros C.III.