Pützer Jackdaw

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Pützer Jackdaw
Type: Motor sailer
Design country:

Germany Federal RepublicFederal Republic of Germany BR Germany


Alfons Pützer KG

First flight:

December 1956 (Jackdaw I),
September 2, 1957 (Jackdaw II)



Production time:


Number of pieces:


The Pützer Jackdaw was a test aircraft for long-distance wave testing that was built in 1956 by Alfons Pützer KG for Walter Horten . Alfons Pützer later used the jackdaw for field testing as a motor glider .


Test aircraft

Around 1955 Walter Horten was interested in developing a long-distance shaft drive for his flying wing aircraft. He commissioned Prof. Karl Lürenbaum's Institute for Engine Dynamics at RWTH Aachen University to develop a corresponding drive. Walter Horten commissioned his childhood friend Alfons Pützer to build a suitable test vehicle for long-distance wave testing. Pützer suggested the use of a double- rack construction by Fritz Raab , which had already been used at Pützer Motorraab .

Pützer then commissioned Fritz Raab to modify a Doppelraab 6, in which a small engine was placed in the center of gravity behind the pilot's seat. The tail unit of the Doppelraab was replaced by an end disk tail unit with two side fins, in the middle of which a pusher propeller was arranged at the tail of the aircraft. The two-cylinder two - stroke engine Hansa-Lloyd with 400 cm³ displacement and 12 hp drove the propeller at the stern via the long-distance shaft developed by Karl Lürenbaum. The test vehicle was created at Alfons Pützer KG in Bonn.

In December 1956, the Pützer Dohle took off on its maiden flight in Bonn-Hangelar . For testing in continuous operation, the Bonn air sports club received the jackdaw in early 1957 for training purposes. There were several disturbances in the area of ​​the long-distance wave. The propeller at the stern was also damaged several times.

Further development for motor glider testing

Due to the arrangement of the engine in the center of gravity of the aircraft and the pusher propeller at the stern, the basically good gliding characteristics of the Doppelraab were retained in the jackdaw. Alfons Pützer then further developed the jackdaw as a motor glider. He replaced the weak and too heavy Hansa engine with an Ilo F2x376 with 30 hp, with which the Dohle II should be able to self-start. The small tank for 14 kg of fuel was replaced by a 40 kg tank for longer cruises. This allowed the Jackdaw II to stay in the air for up to five hours. To protect the stern propeller from contact with the ground, the Jackdaw II received a tail wedge at the stern.

Jackdaw II was created in 1957 by converting Jackdaw I at Alfons Pützer KG. She took off on September 2, 1957 in Bonn-Hangelar with the provisional approval D-EGUB for her maiden flight on her own. The Dohle II was one of the first usable motor glider designs in Germany in 1957. However, Alfons Pützer had to stop further testing a short time later, as the establishment of series production of the Pützer Elster in the winter of 1957/58 occupied all capacities at Alfons Pützer KG.

The basic structure of the Jackdaw II was later the starting point for the development of the Pützer Bussard trainer aircraft , which should also be equipped with a pusher propeller at the stern to achieve jet-like behavior. The first drafts of the Bussard show a completely redesigned fuselage and low-lying wings. As with the Dohle II, the tail unit was the end disc tail unit with a wedge spur. This tail unit was later replaced by a V-tail unit on the Bussard.

Only after the successful start of Elster production did Alfons Pützer take up the development of a motor glider again at the end of 1958. Drafts from this period show a further developed jackdaw with the V-tail already used on the Bussard and a low-lying wing. From 1959, however, Alfons Pützer gave up the further development of the jackdaw in favor of the completely new motor glider design Pützer MS-60 . The Jackdaw II was parked in 1960.

Unless otherwise stated, the information on the Pützer Dohle has been adopted.

Technical specifications

Parameter Jackdaw I Jackdaw II
crew 1
length 7.20 m
span 13.20 m
height 2.00 m
Wing area 18.00 m²
Wing extension 9.7
Glide ratio
Slightest sinking
payload 120 kg 125 kg
Empty mass 300 kg 325 kg
Max. Takeoff mass 420 kg 450 kg
Cruising speed
Top speed
Service ceiling
Engines 1 × Hansa-Lloyd, 12 hp 1 × Ilo F2x376, 30 PS

See also


Web links

Individual evidence

  1. ^ Lothar Franz: History of the air sports club Bonn Rhein-Sieg
  2. ^ Paul Zöller, Hanns-Jakob Pützer: Pützer aircraft. Dec. 2018, ISBN 978-3-7481-2096-4
  3. ^ A b Hans Zacher: The development of motor gliders in Germany. Swiss Aero Review 1964/1