Hannover CL-II, CWL.18 Słowik. 1919
The designation of the Hannover-Roland CL-II aircraft was common only in Poland, due to the fact that they had aircraft from these two manufacturers. In other countries, the aircraft is most often called Hannover CL-II. The name CWL 18.01, CWL "Słowik" or CWL SK-1 refers to the Polish variety, which was to be mass-produced at the Central Aviation Workshop.
Description for the photo: The photo was taken on the day of the official presentation and the crash on August 23, 1919.
Hannover CL.II in Poland.
After the World War II, a dozen or so CL.II planes remained in Pole Mokotowskie. They were taken over by the reborn Polish Army. The planes were in various technical conditions. On December 20, 1918, the Central Aviation Workshop was established on the basis of renovation workshops. They dealt with the renovation of airplanes, engines and started the production of propellers.
Hannover CL.II machines were among the first overhauled aircraft. At that time, these were relatively modern planes and could serve in the army for several more months. Central Aviation Workshops have refurbished at least 14 (17) Hannover CL.II airplanes. They received Austro-Daimler Benz Bz-III or Bz-IIIa engines. Machines from the CL.II and CL.IIa series, after assembly and renovation in CWL, received the number Type 8 (CWL Type 8).
It is not known exactly how many Hannover CL. II planes were adopted by the Polish Army. It is estimated that there were 23-24 of them and about 10 used in the Greater Poland Army. Most of the machines were renovated at the Central Aviation Workshop. Some planes were renovated there a second time. There were also several planes that were obtained semi-legally from Germanania from private offers. Among the planes used by the Polish Army, there was also one CL.IIIa purchased near Częstochowa from a German pilot. Probably the Germans officially offered the Hannover CL.IV planes to the Polish website and at a favorable price. However, they demanded payment in cash and credit was not an option. It was much more advantageous for Poland to tie up with France, which had no worse planes, and from a political point of view it was a much better deal. In addition, France offered a loan which was used.
Polish CL. II took part in battles on the Ukrainian front, in the war with the Bolsheviks, on the front in Lithuania, on the Pomeranian front and over Upper Silesia.
The CL.II planes were incorporated into almost all Polish squadrons. Planes had a different opinion among aviators. They were easy to pilot, maneuverable, and difficult to shoot down. The plane reached a high altitude. At low speeds, the plane was still stable and controllable. It was suitable for the shooting of senior pilot figures. A good position of a shooter with a large firing field was appreciated.
However, CL.II planes had a low maximum speed, short range and flight time. The engines were heavily worn and therefore consumed a lot of fuel. When he severed the engine, the plane had a tendency to lower its nose. The gyroscopic effect of the propeller was relatively large (almost as if the plane had a rotary engine) and the plane tended to turn left. Much depended on the propeller used. Visibility from the pilot's seat is very poor. The canopy of the wing is at the level of the pilot's face. Pilots often put a blanket folded several times on the seat.
In January 1921, the last welded planes were transferred from the first line to aviation schools in Grudziądz and Ławica, or to the depot in Ławica. The last CL.II was removed from the state of the Polish Army in 1922 (1923).
A test of serial production of CWL 18 Słowik (Hannover CL. II) in Poland.
Almost from the very beginning, the Central Aviation Workshop (CWL), in addition to repairs, also conducted construction activities. In March and April 1919, a universal engine mount was installed for six Hannover CL.II aircraft according to the idea of Eng. Eberman. All planes received Benz Bz-III or Bz-IIIa engines.
Due to the difficulties with obtaining new aircraft abroad, in March 1919, a decision was made to copy the Hannover-Roland CL. II aircraft and start its serial production. The decision was made after consultation with pilots and assessment of the feasibility of the type. The construction team was headed by Eng. Lieutenant Karol Słowik. It was expected that 45 aircraft of this type would be produced from July 1919 to March 1920. Various obstacles, especially material ones, were encountered. It was even difficult to obtain the right plywood and steel tubes. Some of the materials were obtained from scrapped old airplanes.
In May 1919, the construction of the first batch of three airframes began, although material for ten aircraft had already been collected. The batch was given the number 18 (CWL type 18). The Austro-Daimler engine, Ba 17000 version, was used for propulsion. The aircraft was completed in July 1919. Even before the first flight, comments were made about the design, but it was finally decided to allow the plane to fly. The prototype is marked differently: CWL 18.01, CWL "Słowik" or CWL SK-1.
The first CWL 18.01 aircraft made its first flight on August 9, 1919. The flight was made by Lieutenant Bolesław Skarba. The plane was named - Orzeł Biały. The plane was painted entirely white, with White Eagles painted on a red background on both sides of the fuselage and white and red checkerboards on the fuselage, wings and tail.
On August 23, 1919, in Pole Mokotowskie, the dedication ceremony and public flight show of the first plane built from scratch in the Republic of Poland took place. The Head of State, Marshal Józef Piłsudski, attended the ceremony, accompanied by generals, members of the government and parliament. After the mass and the act of blessing the plane, a flight show was to take place. Everything was fine after take-off. The crew made one or two laps over Pole Mokotowskie.
However, the show ended in a plane crash. Wings broke and the plane fell to the ground near the audience, near the military hangars. The crew died in the remains of the plane: Lieutenant Eng. Karol Słowik and Sec. pilot Kazimierz Jesionowski. Marshal Józef Piłsudski, with his mustache lowered, took his place in the car and drove away. It was then that a misconception arose, cultivated especially in People's Poland, that Józef Piłsudski was not a supporter of aviation.
The Hannover CL-II "Słowik" No. 18.2 aircraft was subjected to load tests using sandbags. With an incomplete load, about 50%, the upper wing node (fitting) did not withstand and was damaged as much as Hannover CL-II "Słowik" No. 18.1. The study also showed that the rear upper wing spar was too weak. The stiffening lines used were not suitable for this purpose. The lines stretched and did not return to their length. The construction of the next Hannover CL-II "Słowik" aircraft was abandoned.
In January 1920, Major Pilot Engineer Zdzisław Zych-Płodowski became the head of the Central Aviation Workshop. The new manager proposed to modernize the Hannover CL-II aircraft used in Poland. The modernization consisted in the replacement of worn, unreliable and weak Argus Opel engines, 132 kW (180 HP), with Mercedes Benz engines, 147 kW (200 HP), which were in stock in Polish warehouses. The engines were replaced during repairs of Hannover CL-II aircraft. The new engines fitted into the stock after minor changes. The fuel installation needed to be changed. The engine housing (bonnet) remained unchanged. The Mercedes Benz engine was slightly taller and the exhaust pipe protruded high above the canopy, so visibility from the plane was more limited.
The new aircraft was designated the Hannover CL-IIE and was liked more by pilots than the Hannover CL-II and Hannover CL-IIa. It is not known exactly how many Hannover CL-IIE aircraft were modified. It is estimated that there were no less than three planes. Already at the beginning of 1921, Hannover CL-II planes were withdrawn from service in the Polish Army.
Written by Karol Placha Hetman