in the Battle of Bzura, and then staffed the Modlin Fortress. When the fortress was overrun on September 29, 1939, he was taken prisoner of war and placed in the Działdowo prisoner's camp, from which, after several days, per the capitulation agreement, he was released. He returned to Warsaw changing his name and address in order to safely join the Polish resistance. From January 1940 he was employed by the local Electric Transit Authority (EKD) as a conductor and motorman; then, as a technician in the Division of Track. He worked for this company until August 1944. However, from November 1942, he was also a member of the Polish Home Army (Armia Krajowa) in its diversionary division named "Wachlarz". Operating under nom de guerre that included "Aga" and "Dzięcioł". Among his covert activities, he constructed railroad mines. He survived the Warsaw Uprising and its outcome by absconding from a German military convoy transporting Poles, returning to live in Milanówek. This was his residence until 1966. Also in the years 1942-1944 that predated the Warsaw Uprising, he carried on a secret production and distribution of soap, which in addition to providing financial relief for the participants, was done in order to accrue the capital and production means to restart a modest aviation factory come the war end. This was done jointly in an informal co-op with fellow aviation engineer Roman Berkowski and aviation designer Bronisław Żurkowski. After the war The aforementioned effort to restart the private production of airplanes could not be realized in Communist Poland. The machine tools and accrued tools and measuring instruments ended being taken over and then sold at auction by the government. Meanwhile, In 1945, for the Ministry of Communications, he projected the construction of the high voltage line between Otwock and Miłosna suburbs. During 1945 and 1946, Chyliński took part in an open competition of the Civil Aviation Department for developing a training glider, in which he won the first prize with his project of a motor glider, the HWL Pegaz. From 1946 to 1947 Chyliński together with designer Bronisław Żurakowski, per agreement with Poland's Department of Civil Aviation (Departament Lotnictwa Cywilnego), developed the construction plans for the "Pegaz". At the same time, he was working with the Aviation Department Headquarters of the Polish Scouting and Guiding Association (Związek Harcerstwa Polskiego). The design team also included the technicians Waszkiewicz and Brewiński. The engine for the