During 1934, the aircraft manufacturer
Klemm Leichtflugzeugbau started work on a new production site at
Halle; it was completed two years later. This facility was purpose-built for the production of all-metal aircraft (as opposed to Klemm's traditional light aircraft, which had been composed of
wood and
fabric instead) and thus was a major part of the company's next major project, the development and production of a new five-seat twin-engined light transport aircraft. This aircraft was originally designated
Klemm Kl 104 prior to the type being redesignated
Fh 104 and receiving the name
Hallore. In terms of its construction, a large proportion of the aircraft, including the fuselage and tail unit, were composed of
duralumin while the exterior featured numerous clean lines. It became known as the 'Hallore' after the name given to those born in that city. During 1938, quantity production of the type commenced; differences between the prototypes and production standard aircraft included the adoption of the
Hirth HM 508D V-8 piston engine along with the use of twin-blade
variable-pitch propellers. In response to demand, the company opted to develop an enlarged derivative of the type, designated
Siebel Si 204. In May 1942, production of the Fh 104 ceased in favour of concentrating resources on the larger and more popular Si 204 instead, a total of 46 aircraft were completed. ==Operational history==