PWS 3

The PWS 3 was the first sports aircraft manufactured by the Polish aerospace industry not counting earlier amateur designs. It was designed by Stanislaw Cywinski in the PWS factory in 1927. The fuselage is built upon a bottom boom, what made possible changing of upper fuselage part with cockpits, and developing single-seater, two-seater or other specialized variants.

The PWS 3 was a two-seater parasol wing braced monoplane of wooden construction. The fuselage was built around a box-section wooden boom, with a superstructure of wooden laths, covered with plywood and fabric the front fairing of the aircraft in the rear. The engine compartment was covered with duralumin plating. The empennage was wooden, with a fixed surface, made of plywood and fabric on the control surfaces. The rectangular wooden wings had two spars and was covered with plywood in front and cloth in rear. Originally slotted ailerons on the whole wingspan, later to be shortened. The fuselage had a cockpit for two in tandem, with windscreens and dual controls. The chassis consisted of a fixed split axle conventional chassis, with a rear skid. Both main landing gear and wing struts were installed a small horizontal winglets at the bottom of the fuselage. Fuel in two tanks, 100 litres in total, in the Central section of the wing.

The 5-cylinder Walter NZ 60 radial air-cooled engine provides a nominal power of 60 HP and take-off power of 65 HP, driving a two-bladed wooden fixed pitch propeller. The cruise fuel consumption was 22 l / h.

Prototype 3 PVA designated 3B and issued registration number R-PWSS, was flown on May 20, 1927 in Biała Podlaska. After testing, the handling improved. In 1928, the aircraft underwent modifications, having a rounded tip rather than square, and less aileron.

It took part in the 1st competition of the Polish light aircraft from 6 to 9 October 1927, finishing in 2nd place.

Re-registered SP-ACJ in 1930.

Later it was bought by the Lopp paramilitary organization in Lublin and used for propaganda flights.

PWS 33 Wyzel

Reconnaissance and Liaison Aircraft, Poland, 1936

Engines: 2 x De Havilland Gipsy Major 4 B, 128 hp
Length: 22.769 ft / 6.94 m
Height: 8.399 ft / 2.56 m
Wingspan: 30.381 ft / 9.26 m
Wing area: 136.703 sq.ft / 12.7 sq.m
Max take off weight: 3219.3 lb / 1460.0 kg
Weight empty: 1014.3 lb / 460.0 kg
Max. speed: 170 kts / 315 km/h
Cruising speed: 140 kts / 260 km/h
Service ceiling: 14764 ft / 4500 m
Wing loading: 23.58 lb/sq.ft / 115.0 kg/sq.m
Range: 626 nm / 1160 km
Crew: 2
Armament: 2x MG

PWS 26

The PWS.26 was a two-seat advanced military trainer development of the PWS.16bis and PWS.18

The fact that only 36 PWS.26 trainers were assembled at SET Bucharest from ex Polish components, is only part of the story. The existence in 1942 and 1943 of this type in several schools wearing numbers in the 200 and even 300 series (the highest serial numbers known were 269 and 310, respectively) denotes, that actually many more PWS.26s existed in the ARR than the ten ex Polish Air Force PWS.26s (one later escaped to Bulgaria), the 27 supplied by Germans and those 36 assembled at the SET plants.

Rovno, eastern Poland

The bulk were operated by the Central Flying School at Deblin. Several were operated by the Luftwaffe.

Engine: 220 hp Avia-Wright Whirlwind
Max speed: 130 mph
AUW: 2420 lb
Time to 3400 ft: 4 min
Service ceiling: 14,400 ft
Armament: 1 x 7.7mm mg
Bombload: 2 x 25 lb
Span: 29 ft 9 in
Length: 22 ft 11 in
Height: 8 ft 10 in

PWS 24T

Designed to seat six passengers and crew, the PWS-24T was operated by LOT Polish airline on the feeder route from Warsaw to Posan.

First flown in 1931, the PWS-24T was initially powered by a 220 hp Skoda-Wright Whirlwind. Experience showed the Whirlwind-PWS 24T was under-powered and the engine was replaced by the 420 hp Pratt & Whitney Wasp Junior.

Performance was improved to give a cruising speed of 110 mph and maximum speed of 139.5 mph, for an AUW of 4800 lb. Service ceiling was 11,400 fpm.

Some PWS-24T retained the lower power Whirlwind and served as crew trainers and for aerial mapping duties undertaken by LOT on behalf of the Government.

PWS 18

In April 1935, the Polish government, looking for an intermediate military trainer, bought two Avro 621 Tutor trainer aircraft. Production was ordered in the PWS (Podlaska Wytwórnia Samolotów – Podlasie Aircraft Factory). Negotiations began for licensed production in Poland but reached an impasse. Under the contract, the Polish Avro 621 were equipped with Bristol engines, and the engine production in Poland has not yet been established. When the license was obtained, there is a problem with the release of the licensed copies of the aircraft. As a result, both Avro 621 were sent to Podlaska Wytworna Samolotow (PWS) to review the design.

In 1935, Antoni Uszacki of the PWS modified the design, fitting it with a Wright Whirlwind engine, produced under licence in Poland. The new engine cowling was much longer than the previous Townend ring type, with a carburetor air intake below it. The wing construction was changed from metal to wooden, better fitted to PWS capabilities, and the rectangular wing tips were rounded. Also some other details were changed, such as a tailskid instead of a tailwheel.

A series of 40 aircraft was built in 1935-1936. They were assigned military numbers 80-1 to 80-40. Designated PWS 18, these machines differed only “cosmetic” improvements and American Wright J-5B “Cyclone” engines.

They were not produced in larger numbers because a successful indigenous Polish advanced trainer, the PWS-26, using the same engine, was designed and entered production.

PWS-18s were used in the Polish military aviation flight schools and training squadrons of the 4th Regiment in Torun, among others in Airforce Training Center in Dęblin, an NCO school for minors in Bydgoszcz and in training escadres of air regiments. None survived World War II.

Most of the aircraft survived until the outbreak of war, and for some time they have been used to provide communications between the Polish armies. Some PWS 18 were then captured by the Germans and used in flight schools Luftwaffe in Poland.

Gallery

Engine: 1 × Avia Wright Whirlwind J-5B, 240 hp / 220 hp nominal (176 kW / 162 kW nominal)
Wingspan: 10.98 m (36 ft ⅛in)
Wing area: 29.40 m² (316 ft²)
Length: 8 m (26 ft 2⅞ in)
Height: 2.92 m (9 ft 6⅞ in)
Empty weight: 926 kg (2,037 lb)
Loaded weight: 1,220 kg (2,684 lb)
Wing loading: 41.5 kg/m² (8.49 lb/ft²)
Power/mass: 0.144 kW/kg (0.0894 hp/lb)
Maximum speed: 196 km/h (106 knots, 122 mph)
Cruising speed: 169 km / h
Range: 465 km (251 nm, 289 mi)
Service ceiling: 4,900 m (16,000 ft)
Rate of climb: 5 m/s (980 ft/min)
Crew: 1, instructor
Capacity: 1, student
Armament: 1 x 7.92 mm machinegun, pilot’s or observer’s (optional),
Bombload: 2 x 12-kg bombs (optional)

PWS 10

The PWS-10 was the first Polish-designed fighter intended for military service as a replacement for the numerous foreign designed, Polish constructed aircraft then operated.

A single-seat fighter, the PWS-10 was first flown in 1928. Sixty-five were delivered to the Polish Air Force.

The parasol-winged inline-engined PWS-10, the first Polish fighter to enter series production, served in the Spanish Civil War.

Engine: 450 hp Skoda-Lorraine 12 cyl W
Span: 36 ft 0 in
Length: 24 ft 7.5 in
Height: 8 ft 6 in
MAUW: 3290 lb
Max speed: 152 mph
Time to 16,300ft: 15 min 15 sec
Service ceiling: 21,300 ft

Pobjoy Niagara / Cataract / Cascade

Pobjoy Niagara

The Pobjoy Niagara is a British seven-cylinder, air-cooled, radial, aero-engine first produced in 1934. The design ran at higher speeds than conventional engines, and used reduction gearing to lower the speed of the propeller. This led to a noticeable off-centre mounting for the propeller. The Niagara was a popular engine for light and experimental aircraft, well regarded due to their small diameter, smooth operation, low noise and innovative engineering.

Variants:
Niagara I
Bore/stroke 77 x 87 mm (3.03 x 3.43 in)
Swept volume 2,835 cc (173 cu in)
Compression 6.25:1
Gearing 0.47:1
Normal continuous power 84 hp (63 kW) at 3,200 rpm at sea level.

Niagara II
Bore/stroke 77 x 87 mm (3.03×3.43 in)
Swept volume 2,835 cc (173 cu in)
Compression 6.0:1
Gearing 0.39:1
Normal continuous power 84 hp (63 kW) at 3,200 rpm at sea level.

Niagara III
Bore/stroke 77 x 87 mm (3.03×3.43 in)
Swept volume 2,835 cc (173 cu in)
Gearing 0.47:1
Normal continuous power 88 hp (66 kW) at 3,300 rpm at sea level.

Niagara IV
Similar to Niagara III but with a higher operating rpm.
Normal continuous power 98 hp (73 kW) at 3,500 rpm at sea level.

Niagara V
Larger version of the basic Niagara.
Bore/stroke 81 x 87 mm (3.19 x 3.43 in)
Swept volume 3,138 cc (192.5 cu in).
Compression 8.0:1
Gearing 0.47:1
Normal continuous power 125 hp (93 kW) at 4,000 rpm at sea level.

Cataract I-III
De-rated, uncowled versions of Niagara I-III with simple inter-cylinder baffles for cooling and trickle-down lubrication for lower exhaust rockers.
Compression 5.7:1
Gearing 0.47:1

Cascade
Direct drive version of Cataract I.
Normal continuous power 66 hp (49 kW) at 2,100 rpm.

Applications:
Niagara –
Aeroput MMS-3
Airspeed Fleet Shadower
CLW Curlew
Comper Kite
Comper Swift
General Aircraft Monospar ST-25
General Aircraft Fleet Shadower
Lambach HL.I
Pobjoy Pirate
Saro Shrimp
Shapley Kittiwake
Short Scion Senior
Short Scion
Short Stirling (half scale prototype)
Spartan Clipper

Cataract –
British Klemm Swallow
Hafner A.R.III Gyroplane
Hendy Hobo

Cascade –
Autogiro AC-35

Specifications:
Pobjoy Niagara IV
Type: 7-cylinder, air-cooled, radial engine
Bore: 3.03 in (77 mm)
Stroke: 3.43 in (87 mm)
Displacement: 173 cu in (2.8 lt)
Diameter: 26.5 in (673 mm)
Dry weight: 130 lb (59 kg)
Valvetrain: 1 inlet and 1 exhaust valve per cylinder
Fuel system: 1 Claudel-Hobson carburettor
Fuel type: 70 octane
Cooling system: Air-cooled
Power output: 98 hp at 3,625 rpm max at sea level
Compression ratio: 6:1
Power-to-weight ratio: 0.75 hp/lb

Pobjoy R

Pobjoy R

The Pobjoy R was a British seven-cylinder, air-cooled, aircraft engine designed and built by Pobjoy Airmotors. Introduced in 1926 it was a popular engine for ultralight and small aircraft in the 1930s. A notable feature of the Pobjoy R was the propeller reduction gear which allowed the engine to operate at high RPM.

Applications:
British Aircraft Swallow
Comper Swift
Cosmopolitan Light Plane
Couzinet 101
General Aircraft Monospar
Hendy Hobo
Kay Gyroplane
Lippisch Delta IV
Mauboussin M.121P Corsaire Major
Miles Satyr
Pander Multipro
Pobjoy Special
Short Scion
Short Scion Senior
Spartan Clipper

Pobjoy R
Type: 7-cylinder air-cooled, radial, left-hand tractor
Bore: 3.03 in (77 mm)
Stroke: 3.43 in (87 mm)
Displacement: 173.05 cu in (2.84 L)
Diameter: 25.5 in (647.7 mm)
Dry weight: 135 lb
Oil system: Dry sump
Cooling system: Air-cooled
Power output: 85 hp
Specific power: 0.5 hp/cu in
Fuel consumption: 4.9 imp. gallons per hour
Power-to-weight ratio: 0.63 hp/lb