History Construction Tally

PZL-37 Łoś. 1936.

Kraków 2012-11-01

Section 1936-12-13

PZL PZL-37 Łoś

Poland

Bomber

Construction

PZL-37 B Łoś replica registration 803-N Mielec 29.09.2012. Photo of LAC
PZL-37 B Łoś replica registration 803-N Mielec 29.09.2012. Photo of LAC

PZL-37 B Łoś 1938. Photo of LAC
PZL-37 B Łoś 1938. Photo of LAC

PZL-37 Łoś is a medium bomber aircraft designed for day flights. Built in 1936. In 1937, the introduction of aircraft to the equipment of Bomb Squadrons began.

The crew of the aircraft was four pilots.

Wing

Three-parted wing, with trapezoid-elliptical outline, with smooth working cover, double-girder. Completely made of aluminum alloys. It consists of a center wing and external attachments. The center wing ends behind the engine nacelles and main landing gear chambers. The center wing has a caisson structure, partly open at the bottom. There were wing bomb chambers. Bomb chambers are equipped with bomb fixing nodes, replaceable depending on the bomb weight meter used. The cover is made of grooved aluminum alloy sheet, fastened by rivets with flat heads. The outer parts of the wings were made in identical technology. On their leading edge, automatic two-part slots were used, blocked by the pilot. The trailing edge of the flap, on the outside, is equipped with classic slotted ailerons, without balancing flaps. Only small plates were used, which can be set manually before the flight. The rest of the runoff was equipped with two-piece crocodile flaps. They are extended pneumatically and hydraulically retractable. At the end of the right wing, an ejector housing 4 signal or lighting flares has been mounted. On the right wing, along the side, there is a pavement, after which you get into the front cabin. The wings have a laminar profile JD 12 / P-37.

Fuselage

The fuselage has a half-shell structure, with a contour similar to the wing profile, both in horizontal and vertical section. Oval cross section. All metal. The basis is duralumin frames to which the side members are attached, with a Z-section. The whole is covered with duralumin sheet metal, 0.8 to 2.0 mm thick.

The fuselage nose is richly glazed. Here is the crew commander's place. He served as a pilot, observer, navigator, bombardier and front deck gunner. He had bombarding sights, a single machine gun, tiller (slightly shifted to the right), basic navigation instruments and more.

The pilot stand was placed in the upper part of the hull. The glazing consists of a permanent windscreen and deflected to the left side of the fairing, with numerous windows. The upper windows have been tinted blue or blue-green. The wind deflector in an emergency situation can be easily rejected. The pilot's seat slightly moved to the left side of the cabin. The pilot has control wheels in the form of a shuttlecock and adjustable pedals. Both the commander and the pilot boarded the plane through the fairing of the pilot's cabin. The commander got in first. When they both piloted, they used most of the common avionics instruments.

Behind the pilot's cabin there is a radiotelegraph-shooter station. He has at his disposal a Polish radio station licensed by Philips N1L / L. In addition, it has a barometric altimeter, speedometer, watch and more. An antenna stand with a Pitot probe was placed on the hull crest. In the lower part of the fuselage there is a bomb chamber closed with a two-part door. Lower and upper shooting position behind the hull. Heated cabins.

Tail-plane 

In the prototype (PZL-37 / I) and the first ten copies (PZL-37 A) the classic tail, with a single vertical tail. On all other H-shaped machines (with two vertical tailings). The main purpose of the change is to improve the firing field for the rear-upper gunner. The crest is self-supporting, double-girder, duralumin, covered with smooth sheet metal. Each tail consists of a rudder and ballast. Rudders equipped with trimmers.

Landing gear

The prototype was made with a main chassis with single wheels on doubled legs. However, when landing on unadjacent terrain, it turned out that the landing gear is hard and the plane does not tolerate all unevenness badly. That is why the chassis has been redesigned. The new chassis was developed by engineer Piotr Kubicki. For the first time in the world, an independent twin wheel suspension system was used. This meant that they could work independently in uneven terrain. Each wheel was evaded individually. It allowed not only for typical operation from field airports, but for safe landing even on a potato field. The chassis turned out to be sensational and was patented by PZL - Polish Patent No. 29090.

Chassis spacing about 5 m. Oil-air cushioning by Avia. Tire size 755 x 440. Hydraulic brakes from Dunlop. Retractable hydraulic undercarriage. On the upper surface of the gondola, there are mechanical indicators of landing gear extension and retraction, sometimes called soldiers. Rear skid of the PZL system with an auxiliary metal roller, self-adjusting, with Avia oil-air shock absorber.

Engins

Two very good engines with 9 cylinders, single star, turbo-charged were used for the drive. Manufacturer Bristol type Pegasus. These engines were also produced under license in Poland. Engine diameter 1.404 m, weight 467 kg.

Hamilton Standard 3-blade propellers, metal, adjustable. They can occupy two positions. 3.50 m diameter.

87 octane fuel. Starting with an Avia-Eclipse 11A inertial electric starter. The engines are covered with duralumin profiled covers.

Bristol Pegasus XII with take-off power of 685-714 kW (930-970 hp) at 2 475 rpm. Nominal power 604-633 kW (820-860 HP) at 2,250 rpm at an altitude of 1,220 m.

Bristol Pegasus XX with take-off power 663-692 kW (900-940 HP) at 2,600 rpm. Nominal power 597-626 kW (810-850 HP) at 2,250 rpm at an altitude of 2,600 m.

Bristol Pegasus XIX - only the reducer differs from the Pegasus XX version.

Bristol Perseus X - experimental valveless engine with a nominal power of 516-538 kW (700-730 hp) and a maximum of 648 kW (880 hp). These engines in 1939. mounted on two aircraft.

Gnome-Rhone 14 N 00/01 - in a double star system, with a nominal power of 700 kW (950 hp) and a maximum of 722-751 kW (980-1 020 hp), used only on copies offered for export. They were mounted on PZL-37 / III and PZL-37 C machines.

Gnôme-Rhône 14 N 20/21 - in a double star system, with a nominal power of 758 kW (1 030 HP) and a maximum of 810 kW (1 100 HP). They were mounted on the PZL-37 D machine.

Fuel tanks

The aircraft is equipped with 5 tanks located in the airframe. The first tank was placed under the pilot's cabin (532 liters). Two tanks at the base of the central wing (2 x 238 liters). Two tanks located behind the engines (2 x 119 liters). A total of 1,246 liters, or 945 kg. It is possible to mount two tanks in a bomb chamber with a capacity of 2 x 369 liters.

The oil installation consisted of two tanks in the nacelles of 2 x 115 liters engines.    

Armament

Defensive armament on the Łoś A and A bis aircraft were initially Vickers F machine guns. Later, standard PWU machine guns wz. 37 Puppy with sights FK wz. 38. Three movable machine guns are mounted at the shooting positions; front, bottom and rear. Firing field; front rifle - top and sides up to 25 degrees, down 45 degrees. Upper rear rifle - up 60 degrees, down 10 degrees, 85 degrees sideways. Rear bottom rifle - down and sideways up to 60 degrees.

PZO RH-32 and Goertz-Boykow Bombardon Sight. The aircraft takes a maximum of 2,595 kg. Nominal 2,200 kg. Typically, an airplane takes on board up to 20 bombs with a weight of 100 - 110 kg. Other typical arrangements; 20 bombs of 50 kg, 18 bombs of 100-110 kg, 2 bombs of 300 kg. In the bomb chambers, mechanical and electric ejectors were used.

Data T-T PZL-37 Łoś

Data T-T PZL-37 Łoś
Data T-T PZL-37 Łoś

PZL-37 B Łoś. Photo of LAC
PZL-37 B Łoś. Photo of LAC

PZL-37 B Łoś. Photo of LAC
PZL-37 B Łoś. Photo of LAC

Written by Karol Placha Hetman