Poland's Little Known Elk: The PZL P.37 Los

By Jason Long

The PZL P.37 Los (Elk) was conceived as a replacement for Poland's obsolescent Fokker F.VIIb-3m tri-engined bombers in 1934. Contrary to most bomber designs of its era the Los substituted speed for a heavy defensive armament, although it mounted the three rifle-caliber machine-guns common to most bombers of its day. The smaller aircrew required would allow for a lighter, smaller aircraft that would minimize the horsepower required to achieve the high speeds intended. Given that Poland had to import engines from Britain or France that weren't state-of-the-art this was critical to the success of the bomber.

Jerzy Dabrowski designed a very sleek and aerodynamically clean aircraft that only carried a pilot, navigator/bombardier and radio operator/gunner, but could lift a 2600 kg. (5732 lbs.) bombload, greater than any other twin-engined bomber of its time. It could carry a load of fuel, bombs and equipment that eas greater than its empty weight. The first prototype flew 13 December 1936 and evidenced the typical teething problems.

The Lotnictwo Wojskowe (Polish Air Force) ordered 30 pre-production bombers that used the same 860 hp Bristol Pegasus XIIB radial engines as the first prototype. Only the first ten of these had the single tail, and were designated as P.37A, but in most respects all the Los A and A bis bombers incorporated the changes introduced in the second prototype, including the twin tail. Service use revealed a problem with overbalanced rudders that locked solid at certain angles at high speeds that caused no less than eight Los A bombers to crash. Once identified this was easily rectified, but gave enemies of the program ammunition with which to argue for the cancellation of the 150 Los B which the Lotnictwo Wojskowe planned to order.

A third prototype was built to develop export models of the Los, designated Los C and D with different engines, which was designed to accept any radial engine up to 1200 hp in size, although French Gnome-Rhône 14N series engines were the only ones flown. The display of a P.37A bis bomber at the Belgrade Air Show in May '38 where its high speed and great load-carrying ability greatly stimulated interest among PZL's usual customers in Eastern Europe and the Balkans. Furthermore PZL's claim to initiate deliveries within twelve months of ordering fit nicely in the re-equipment plans of a number of those same air forces.

However it was the Spanish Republican government that placed the first order for the Los. This clandestine order was for 50 Los C's, but the Republicans were defeated before deliveries could commence. During the spring and summer of 1939 Yugoslavia ordered 20 Los C's and Bulgaria 15, while Romania ordered 30 Los D's and Turkey 10 with another 15 to be assembled in Turkey, all of which were to be delivered in the spring and summer of 1940. The invasion of Poland interrupted negotiations over Greece's order for a dozen Los C's and discussions with four other nations.

These orders were crucial for PZL as the Lotnictwo Wojskowe had cancelled, in the late spring of 1939, production of the Los other than those in an advanced stage of assembly. The new Air ForceCommander-in-Chief didn't believe that the Los was an appropriate use of scarce money.

PZL's failure to maintain its promised delivery schedule certainly didn't help matters. 124 bombers were to be delivered by 1 April 1939, but PZL had only turned over a small fraction by that date, most of which were P.37A and A bis aircraft that weren't suitable for combat. Only 90 P.37Bs had been delivered when the Germans invaded although a number were awaiting equipment.

Only 36 were assigned to operational units1 September 1939, namely four eskadry assigned to the Brygada Bombowa (Bomber Brigade). They remained on the ground until 4 September while the High Command waffled on their proper use. They were first committed against German armor near Lodz; a role for which they were neither designed nor trained. Seven Los failed to return from the day's operations while two more were caught on the ground by the Luftwaffe.

The Los units continued to fly similar missions, but losses and lack of spares rapidly diminished their numbers despite drafting replacement aircraft from the Los training squadron. The last mission was flown by the P.37B on 16 September as all surviving aircraft were ordered to fly to Romania when the Soviets joined the German attack the next day.

Thirty P.37s of all types reached safety and were promptly impressed into the Romanian Air Force where they equipped two squadrons. The Romanians didn't have a high opinion of the Los, but this was probably because it had considerably better performance than the Romanian bomber pilots were accustomed to. Four had crashed and another four were damaged before the Los was committed to its second war in June '41.

The Romanian Air Force participated in the opening stages of Operation Barbarossa with the Luftwaffe with some effect, but the P.37 was withdrawn from operations after the fall of Odessa in October '41 due to lack of spares. The survivors were relegated to training duties until the spring of '44 when its severe lack of modern bombers forced commitment of the remaining Los for several months on the Eastern Front. They were then returned to training duties. In the confusion of Romania joining the Allies in August-September 1944, the survivors were destroyed on the ground by Hungarian partisans. A sad end to an aircraft that could have been widely acknowledged as the best bomber of its day had it seen more widespread service.

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