The Siebel Si 204 was a small twin-engined transport and trainer aircraft developed in World War II.

Originally designed in response to a German Ministry of Aviation development order for a small civil transport aircraft in 1938, it was eventually produced for the Luftwaffe.

As a result, Société Nationale de Constructions Aéronautiques du Nord (SNCAN) in France produced the A-0 preseries and A-1 production passenger aircraft between April 1942 and November 1943.

Českomoravská Kolben-Daněk (ČKD, called Böhmisch-Mährische Maschinenfabrik AG [BMM] in German) in the Protectorate of Bohemia and Moravia delivered the first instrument flight trainer D-0 in January 1943 followed by production of a further 44 D-0 preseries aircraft.

At 8 p.m. on May 8, 1945, 2nd Lt. K. L. Smith of the 9th Air Force's 474th Fighter Group, flying a P-38 Lightning, downed a Siebel 3 miles southeast of Rodach, Bavaria.

Captured Si 204s flew in a variety of civil roles in the post-war USSR, serving with Aeroflot until 1949, being particularly successful in Tajikistan regional services.

Major engine deficiencies in the extreme climate conditions, with four aircraft lost, caused local aircrew to nickname the Si 204 Giebel, Russian for disaster, before withdrawal from the region.

In France SNCAC (Société Nationale de Constructions Aéronautiques du Centre), commonly known as Aérocentre, produced 240 transport NC.701 Martinets and a number (110?)

[4] Data from Die Deutsche Luftrüstung 1933–1945 Vol.4 – Flugzeugtypen MIAG-Zeppelin,[8] German Aircraft of the Second World War[9]General characteristics Performance Armament