PZL P-37B Łoś - Medium Bomber.

The PZL.37 Łoś (Moose) was a Polish twin-engine all metal medium bomber designed by Jerzy Dąbrowski, with aviation engineering studies carried out by Wladyslaw Zalewski and manufactured by Zygmunt Puławski of the national aircraft company PZL, (Państwowe Zakłady Lotnicze)

Upon its introduction to service, it was popularly considered to be not only the most modern and effective weapon then possessed by Poland, but also to be one of the most advanced bombers then operational in the world.

The Łoś was extensively used in the defence of Poland during the rapid invasion of Poland by Nazi Germany in September 1939. On 1 September 1939, the Polish Air Force had about 86 PZL.37’s in total, but less than a half of those saw active combat use due to aircraft being used by training units, being in maintenance, or having been held in reserve. The bombers suffered from a high attrition rate due to lack of fighter protection, and the final Polish combat missions were performed on 19 September. During October 1940, around 26-27 of the PZL.37s that had been evacuated from Poland were seized by the Romanian government and twenty-three of these aircraft were subsequently used by the Royal Romanian Air Force, including offensive missions against the Soviet Union.