From the Kovozávody Prostějov instructions,
Morane-Saulnier MS.A.1 (also Type A1) was a French parasol-wing fighter aircraft produced by Morane-Saulnier during World War I. A number of escadrilles were created to operate the AI, but by mid-May 1918, most of the aircraft were replaced by the SPAD XIII. After structural problems had been resolved, the aircraft were then relegated to use as advanced trainers, with new purpose built examples being designated MoS 30. Many were used post-war after having been surplussed off, as aerobatic aircraft, including one which was flown by Charles Nungesser.
