Raab-Katzenstein RK 2

Raab-Katzenstein RK 2 Pelican
RK 2a at the ILA 1928
Type:	Trainer aircraft
Design country:	German Empire
Manufacturer:	Raab-Katzenstein
First flight:	August 30, 1926
Production time:	1926-1929
Number of pieces:	24

The Raab-Katzenstein RK 2 Pelikan is a German trainer aircraft from the 1920s.

development

The RK 2 was designed by Paul John Hall in 1926 as the second model of the RaKa aircraft factory founded the year before. The construction of the prototype with the serial number 030 was completed in the first half of the year and on August 30, 1926 the model started its successful maiden flight. Immediately afterwards, a first small series of six aircraft with the serial numbers 031 to 036 was launched. Like the prototype, most of them received an Sh-11 engine with 96 hp and the designation RK 2a. The specimen with the serial number 035 was equipped with a British 82-hp Cirrus Mark II engine and named RK 2b. Later, the last version was the RK 2c with a Sh 12 with 125 hp, which was intended as an advertising aircraft with illuminated advertising for night flights.

At the ILA 1928, the first since the end of World War I , even Raab-Katzenstein was represented with a booth. Three RK 2 took part in the star flight to Berlin carried out at the start. As a special feature, the company presented a cut-away model of a RK 2a, the fuel and oil tanks of which, connected to a dispensing system and prepared with alcoholic beverages, are said to have been used in sales talks with potential customers (see picture in the info box).

Up to 1929 a total of 24 pelicans had been produced, most of which (17) belonged to the RK 2a version. In a price list of the company from 1929, the versions RK 2d with an unspecified Czech Walter drive, the RK 2e with a Sh 14 and even a float version RK 2f, also with a Walter motor, are offered, but these are apparently due to missing Demand were never produced.

commitment

Demonstration of strength with two RK 2 in Berlin-Staaken, 1930

The RK 2 was popular because it was easy to fly and, with a purchase price of around ℛℳ 15,500 including engine and certification, was quite inexpensive training and sports aircraft. Among other things, it was demonstrated at flight events organized by Raab-Katzenstein at irregular intervals. Pilots who became famous later, such as Richard Perlia or Marga von Etzdorf , completed their training on an RK 2 or acquired extended privileges such as aerobatics . The reliability of the design was proven when, on April 14, 1927, Fritz Gröbedinkel, at the time the technical director of the RaKa branch in Cologne and first flight instructor at the associated flight school in Bonn-Hangelar, took an RK 2 to a presentation flight from Berlin-Tempelhof Budapest started via Plauen, Prague and Vienna and covered a total of 1700 km without technical problems. The model was also used more often for commercial sightseeing flights, publicity campaigns (see photo on the right) and aerial acrobatic demonstrations in front of a paying audience, for example by the artist Oskar Dimpel, who from 1931 onwards used an RK 2a (license plate D–1937, later D–EJEF) to increase his attraction, the "Tooth slope" on the trapeze to demonstrate.

construction

The construction of the RK 2 is similar to its predecessor, the Kl 1 Schwalbe . It is a braced, staggered one and a half decker in a composite construction .

The fuselage consists of a tubular steel frame, which is clad with duralumin sheets in the engine area and covered with fabric in the remaining part. The wings of different spans are formed from a wooden frame with fabric covering. They are connected to one another by N-posts. The upper wing has V-struts towards the upper fuselage and I-stems towards the lower wing-fuselage transition. The horizontal stabilizer of the tail unit is supported on the fuselage with I-posts. The chassis consists of the two rigid main wheels connected by an axle and a grinding spur at the rear.

Technical specifications

RK 2b with Cirrus in-line engine

Three-sided view

Parameter	Data (RK 2)	Data (RK 2a)	Data (RK 2b)	Data (RK 2c)
crew	1-2
span	above 10.40 m below 9.10 m	above 10.90 m below 9.24 m
length	7.00 m	7.80 m		7.28 m
height	2.60 m	2.70 m
Wing area	28.70 m²	26.80 m²
Wing loading	26.5 kg / m²	31.3 kg / m²		32.1 kg / m²
Power load	7.9 kg / hp	8.8 kg / hp	10.2 kg / hp	6.9 kg / hp
Empty mass	540 kg	570 kg	580 kg	510 kg
Payload	220 kg	270 kg	260 kg	250 kg
Takeoff mass	760 kg	840 kg		860 kg
drive	an air-cooled seven-cylinder - four stroke - radial engine		an air-cooled four-cylinder four- stroke in- line engine	an air-cooled nine-cylinder four-stroke radial engine
Type	Siemens & Halske Sh 11		Cirrus Mark II	Siemens & Halske Sh 12
Starting power continuous power	96 PS (71 kW) 84 PS (62 kW)		82 PS (60 kW) 73 PS (54 kW)	125 PS (92 kW) 108 PS (79 kW)
Fuel volume	100 l
Top speed close to the ground	120 km / h	139 km / h	130 km / h	145 km / h
Climbing time to an altitude of 1000 m	10 min	13 min	10 min
Service ceiling	3200 m	2400 m	2800 m	3000 m
radius	350 km		450 km	400 km
Flight time	3 h		4 h	3 h

literature

• Rolf Nagel, Thorsten Bauer: Kassel and the aviation industry since 1923 . Bernecker, Melsungen 2015, ISBN 978-3-87064-147-4 .

Web links

Commons : Raab-Katzenstein RK 2  - Collection of images, videos and audio files

• RK.2 pelican. Retrieved April 16, 2018 (Russian, history and photos). 

Individual evidence

1. ^ Marton Szigeti: Raab-Katzenstein . In: Aviation Classics . No. 1/2014 . Motor Presse, Stuttgart, p. 58 .
2. ^ Nagel, Raab-Katzenstein production list, page 68
3. ↑ Circus in the sky . In: Aviation Classics . No. 08/2016 . Motor Presse, Stuttgart, p. 76 .