sentences:  However the PWS-33 could still find a place as a trainer for pilots of PZL.37 Łoś medium bombers, which were also similar in appearance to the PWS-33, and for future heavy fighters such as the PZL.48 Lampart.In summer 1939 production of the first series of 25 aircraft started but they were not completed due to the outbreak of war.After the German invasion of Poland, the first prototype was bombed in PWS factory in Biała Podlaska in September 1939.