The PZL.37 Łoś (“Moose”) was a Polish twin-engine medium bomber developed in the mid-1930s by Państwowe Zakłady Lotnicze (PZL). It was among the most advanced bombers of its time, featuring a sleek aerodynamic design and innovative features such as retractable landing gear and a twin-tail configuration. Despite its potential, the Łoś had limited production and was primarily used in the defense of Poland during the German invasion in 1939.

Following the German invasion of Poland in September 1939, a number of PZL.37 Łoś bombers were captured. The limited number captured was partly due to Polish efforts to prevent the Germans from acquiring these aircraft. In October 1939, Polish workers in factories at Okęcie and Mielec scrapped approximately 30 PZL.37s under the pretext of cleaning up the area before the German authorities could inspect them.

The captured aircraft were sent to the Luftwaffe’s test centre at Rechlin for evaluation. One of these aircraft crashed during testing in May 1940, resulting in the death of its crew.