Contender for 1934 Challenge International de Tourisme. Note different landing gear compared to D-IJIP.

The Kl 31 was a four-seat touring aircraft of mixed construction, something of a novelty for Klemm. Thus development took some time and the wooden three-seat Kl 32 was built for the 1932 Challenge International de Tourisme instead. A series of thirty-six Kl 31s was produced between September 1933 and September 1934. D-IDUM was apparently a Kl 31a XIV model, with XIV referring to the Sh 14 radial engine, but became HA-NAB in Hungary and was then designated as a Kl 31B. HA-NAB impressed as I.814. Photo from: Klemm

The Kl 35B had a 105-hp Hirth HM 504 engine and covered single-strut landing gear, and was available with a removable canopy. Going by the c/n, this airframe was built in late 1937 or early 1938. The Daimler factory in Sindelfingen is seen in the background. Photo from: Böblinger Flughafengeschichten

Klemm reworked the Kl 36 as the Kl 36B, freed from the empty weight restriction of 560 kg (1235 lb) of the 1934 Challenge International de Tourisme. This Kl 35B prototype had a Hirth HM 508 engine. It is listed as registered in March 1936, used by Lufthansa and written off in January 1939. A batch of 50 production Kl 36Bs was ordered with Sh 14 radial engines, but only seven or so were completed. Photo from: Böblinger Flughafengeschichten

The Kl 36B as built in a small series, powered by a Siemens Sh 14 radial engine. Some examples were impressed by the Luftwaffe as liaison aircraft. Photo from: Böblinger Flughafengeschichten

Zirkus Busch was a well-known circus in Germany and used this plane, Teufel (devil) for promotional purposes. The Raab-Katzenstein KL.1 was a fine aerobatic aircraft which originated as the Dietrich-Gobiet DP.XI. Raab and Katzenstein later redesignated it as the RK.1. At least 40 examples are said to have been built. Photo from: Böblinger Flughafengeschichten

The He 46 was an early 1930s reconnaissance aircraft for the new Luftwaffe. Our source says this is an He 46D re-engined with an Armstrong Siddeley Panther radial. D-IFSA was at one point operated by a training establishment in Cottbus. Photo from: Böblinger Flughafengeschichten

Seen at the Klemm factory, D-2299 became G-ACYU and VH-UVE. Flown to Australia in 1935 by Barry Littlejohn and from Australia to South Africa by Lores Bonney in 1937. Photo from: SLUB / Deutsche Fotothek

A replica of the aircraft used by Friedrick Karl Baron von Koenig-Warthausen for his solo flight around the world, departing from Germany in August 1929 and returning in November 1930. A partial replica of the same plane (constructed with sections from the real aircraft) exists in the Mercedes-Benz Museum in nearby Stuttgart.

A replica of the aircraft used by Friedrick Karl Baron von Koenig-Warthausen for his solo flight around the world, departing from Germany in August 1929 and returning in November 1930. A partial replica of the same plane (constructed with sections from the real aircraft) exists in the Mercedes-Benz Museum in nearby Stuttgart.