HUMA Modell Plastic kit 2501 Klemm Kl 35 Schul- und Sportflugzeug — 1:72

What is in the kit

The 2501 represents the Klemm Kl 35, and the documented kit contains 33 parts. The finished model is approximately 104 mm long with a 144 mm wingspan, which corresponds closely with the dimensions expected from a 1:72 representation of the real aircraft.

The kit was offered with six possible aircraft markings, representing a mixture of pre-war German sporting/training aircraft, Luftwaffe machines and the Swedish Air Force. The documented options include:

Deutscher Luftsportverband — D-EBCQ

Deutscher Luftsportverband — D-EYGR

Luftwaffe — DL+UI

Luftwaffe — PF+WhN

Deutscher Luftsportverband — D-ELLY

Swedish Air Force

That selection makes the kit rather more interesting than a straightforward Luftwaffe-only subject, because it allows the modeller to represent the aircraft in both its civilian/pre-war and military training roles.
The real aircraft — Klemm Kl 35

The Klemm Kl 35 was a German two-seat sporting and training aircraft developed during the 1930s by Klemm Leichtflugzeugbau. It was designed as a successor to the Klemm Kl 25 and retained the general philosophy of a relatively light, single-engine, low-wing aircraft, but introduced a distinctive inverted-gull/"broken" wing arrangement.

Development began in 1934 under the requirements of the German Reichsluftfahrtministerium (RLM). Dipl.-Ing. Friedrich Fecher was responsible for the design. The construction followed the RLM's preferred mixed-material approach: the fuselage used steel structure, while the wings and tail were principally wooden, with fabric covering and limited use of light alloy.

The prototype suffered a serious setback when it crashed during testing at Rechlin after a wing failure. Subsequent investigation attributed the accident to the particular circumstances of the prototype rather than a fundamental failure to meet the applicable strength requirements, allowing development to continue.

The aircraft subsequently entered production and became one of Klemm's most important designs. In July 1936 an order for 23 aircraft was placed, with production intended to increase to three aircraft per month. As demand increased, production was expanded beyond Klemm itself.
Production and wartime service

The Kl 35 was particularly important because of its role as a military trainer. Rather than being a combat aircraft, it provided Luftwaffe students with experience in basic flying, navigation, aerobatics and the transition towards more powerful military aircraft.

Several versions were produced. Early aircraft used the 80 hp Hirth HM 60R, while later versions such as the Kl 35B and Kl 35D used the approximately 105 hp Hirth HM 504 A-2. The Kl 35D became the principal Luftwaffe training version. Float-equipped versions were also produced, and the Swedish military operated the type as the Sk 15.

Production was not confined to Klemm. Gerhard Fieseler Werke manufactured the aircraft under licence, producing 365 examples before production there ended in November 1939. Manufacture was subsequently transferred to Zlín in occupied Czechoslovakia. Detailed German production records indicate 1,302 aircraft were ultimately produced for the Luftwaffe, although the overall production total becomes less certain when private and export aircraft are included. Some sources quote approximately 2,000 aircraft, but more detailed production research indicates that figure is probably too high.

The aircraft was exported and/or operated by several countries, including Sweden, Romania, Hungary, Lithuania and Slovakia, giving the Kl 35 a considerably wider service history than its relatively modest appearance might suggest.
Full-size aircraft specifications

For the later Kl 35D, published specifications give approximately:

Length: 7.50 m

Wingspan: 10.40 m

Height: 2.05 m

Crew: 2

Engine: Hirth HM 504 A-2, approximately 105 hp

Maximum speed: approximately 210–212 km/h

Range: approximately 630–665 km

Service ceiling: approximately 4,350–5,100 m

Armament: none

The aircraft's combination of relatively modest performance, two-seat layout and aerobatic capability made it well suited to its training role.