As time passes, it becomes more and more difficult to unearth the history of Bücker aircraft. One of the things that seems to be little understood is the history of the CASA 1133 Jungmeister in Spain.
It seems generally understood that as many as 25 were constructed, with some sources saying they initially had Hirth HM506 in-line engines, before being changed to Siemens power.
Almost every mention of the 1133 that I have found so far are identically worded, meaning that none are reliable.
If anyone knows more about the details of the Jungmeisters that CASA produced, I would love to learn about it and record here.
Thanks!
Thank you to Chris Trieb-Hasenberger who searched through his inbox and found some information that José Luis González Serrano had shared in 2014:
The Spanish Nationalist Air Arm purchased and received 21 Bü 133 Cs, which were completed and shipped to Spain in January (one aircraft), February (5 aircraft), July (5 aircraft), November (4 aircraft), and December (6 aircraft) 1937. Their construction numbers were within the range 1004 to 1027.
These planes were given military serials from 35-1 to 35-21 upon arrival in Spain. One additional aircraft, also Rangsdorf-built, was recovered from the Republican Air Arm when the Spanish Civil War came to an end on April 1, 1939. The plane was c/n 1007 and the military serial 35-22 was allocated to it.
Construcciones Aeronáuticas, S.A. (CASA) built under-licence 25 examples of the Bücker Bü 133 B variant from 1940 to 142. These planes differed from the Rangsdorf-built ones in being powered by the 160 hp Hirth HM 506A inline engine instead of the Siemens Sh 14A radial, and were delivered to the military in 1941/1942. They were allocated military serials from 35-23 up to 35-47, with their CASA construction numbers being 101 to 125 (sometimes appearing as just 1 to 25 in some Spanish oFficial papers).
On November 2, 1945 the military aircraft designation system was changed from just numbers to a combined alphanumerical one. This way both the Rangsdorf-built examples and the CASA-built ones were designated ES.1 within the Higher Trainer class, with individual numbers being just the same they had had previously. Thus, for example, the former 35-3 became ES.1-3 and so on.
Finally, the military aircraft designation system was modified from December 22, 1953, with the former common designation ES.1 being split into two - E.1 for the Siemens Sh 14A-powered examples, and E.1B for the Hirth HM 506A-powered aircraft. You must also know that a short number of C-1.133Ls (i.e. E.1Bs) were fitted with Siemens Sh 14 A engines n the 1950's and thus their military designation and serials were modified accordingly from E.1B to E.1. For instance, the CASA-built E.1B-36 became E.1-36 when powered by a Siemens and then returned to E.1B when fitted back with a Hirth.