Category Archives: Poland

Lublin R-XVI

January 15, 2022Poland, WW2ambulance, Lublin, Poland, Polish Air Force, TransportMarko P.

Poland (1939)
Transport and Ambulance Aircraft – 7 Built

Following a request for a new passenger transport aircraft, the Plage and T. Laśkiewicz aircraft manufacturer developed the Lublin R-XVI. While it was not accepted for production, it would be built in a small series as a successful ambulance aircraft and used up to the Second World War by the Poles.

History

During early 1929, the Polish P.L.L airline, with the assistance of the Ministry of Transport, opened a contest for a new four-passenger transport plane. This aircraft was to be powered by a 220 hp Wright/Škoda radial engine. This contest was heavily influenced by the Polish Department of Aeronautics, which favored domestic manufactures. Aircraft manufacturer Plage and T. Laśkiewicz from Lublin (hence, all their products were named after that city) responded with the R-XI. Ultimately, this contest ended in failure, as none of the proposed aircraft proved satisfactory.

New specifications for a second contest were issued by the end of 1930. This time, Plage and T. Laśkiewicz presented a new model, the Lublin R-XVI design by Jerzy Rudlicki. While being based on the previous R-XI, there were a number of changes, like separating the cockpit from the crew compartment and changing the wing design. The novelty this aircraft introduced was the use of chrome-molybdenum tubes for the structure, a first in Poland, which reduced the weight.

When the prototype was completed, it was flight tested by Wladyslaw Szulczewski in February 1932. In the following months, the R-XVI was tested with different payloads. During these flights, the maximum speed achieved was around 194 km/h (120 mph). During 1932, the R-XVI was used mostly for postal service by the P.L.L. While the R-XVI proved to be satisfactory, its competitor, P.W.S., was chosen instead as the winner of this competition.

A New Role

Although they lost the competition, Plage and T. Laśkiewicz were instead contacted by the Medical Aviation Research Centre in cooperation with the Polish Red Cross. They were interested in the R-XVI plane and asked for certain modifications. These included adding space for two stretchers and a doctor, along with storage for additional medical equipment. This implementation was approved by the Ministry of Transport and the prototype was to be modified for this role. The aircraft was then renamed to R-XVIB, with the SP-AKP registration. Beside the changes to the interior passenger compartment, the fuselage was strengthened. These modifications were completed by the spring of 1933, when the aircraft was flight tested again.

Front view of the converted R-XVIB prototype aircraft. Source: Wiki

At the International Congress of Military Medicine in Madrid

This aircraft was presented to the VIIth International Congress of Military Medicine and the IInd International Congress of Medical Aviation, which was held in Madrid in 1933. Its crew consisted of the pilot, Zygmunt Janicki, mechanic Leon Zamiara and doctor Maj Kazimierz Michalik. The R-XVIB had the honor of being the first medical aircraft in the history of these Congresses to actually directly arrive by air. It also proved to be the best medical aircraft design present. The R-XVIB even won the first prize, the Raphael Cup, by beating the Spanish Trimotor and French Potez 29. When the Polish crews returned, they managed to fly the distance of 5,730 km (3,560 miles) without any problems.

Production Orders

Following the R-XVIB’s success in Spain, Plage and T. Laśkiewicz received production orders for one more prototype and five operational planes. The new prototype was completed during 1934. It was slightly different in comparison to the first aircraft. The most obvious change was the redesigned fuselage, improving the pilot’s visibility and using new types of landing wheels fitted with brakes and shock-absorbers. All aircraft were completed and put into service by the end of 1934.

Technical Specifications

The R-XVI was designed as a high-wing, single-engine, mixed construction transport/ambulance aircraft. The fuselage was built using chrome-molybdenum metal tubes and then covered with fabric. The one-piece wings were built using two spars which were covered by plywood. The wings were connected to the upper part of the fuselage by four bolts. The tail construction was the same as the fuselage, with a combination of steel tubes and fabric.

The R-XVI was powered by a 220 hp Škoda J-5, a nine-cylinder air-cooled radial engine, built under license after the J-5Wright Whirlwind engine. It was fitted with a two-blade fixed wooden propeller. The fuel load was stored in an aluminum tank (257 liters) which was placed in the upper part of the fuselage between the the wings.

The R-XVI high wing design and the fixed landing gear are evident in this photograph.. Source: Airwar.ru

The cockpit was placed at the front of the fuselage. To enter this position, the pilot was provided with a door. The crew compartment had room for four seats and one additional optional seat for a mechanic, if needed during the flight. There was a huge door for the passengers on the starboard side, with an additional smaller door for the luggage compartment on the port side. In the case of the later ambulance version, the crew compartment was redesigned to include two stretchers, placed one above the other. It was also equipped with shock-absorbing mounts for a more convenient flight for the patients. To bring the patients inside the plane, a large door was placed on the starboard side. On the opposite side, there was a door for the medical attendant. The interior of the medical version was provided with a first aid kit, washstand with running water, and lights.

The R-XVIB, which was designed as an ambulance aircraft, had specially designed folding doors to bring the patients inside the plane. Source Airwar.ru

The fixed landing gear consisted of two wheels. These were provided with vertical shock absorbers and brakes. If needed, there was an option to replace the landing wheels with skis. The original prototype had a small tail wheel, which was replaced on the later production model with a tail skid.

In Service

While not a combat aircraft, all R-XVIs were still operational by the time of the German invasion (1st September 1939) of Poland. By the time of the war, they were primarily used for wounded evacuation. While their final fate is unknown, they probably fell victim to the German air force.

Production and Modifications

The R-XVI was built in limited numbers for the Polish Red Cross. Besides the two prototypes, 5 additional aircraft were built.

R-XVI – Original proposed passenger aircraft prototype, later served as the base for ambulance version.
R-XVIB – Modified ambulance version, 6 aircraft were built (including a prototype).

Conclusion

While not accepted in its original role, the R-XVI would still see service as a medical aircraft used by the Polish Red Cross. In this role, they proved to be satisfactory and a small series of 5 aircraft was built. Their final fate sadly is not known and none survived the war.

Lublin R-XVIB Specifications
Wingspans	49 ft / 14.9 m
Length	33 ft 1 in / 10 m
Height	8 ft 7 in / 2.96 m
Wing Area	328 ft² / 30.5 m²
Engine	One 220 hp Wright Whirlwind (Škoda) J-5 nine-cylinder radial engine
Empty Weight	2,535 lbs / 1,150 kg
Maximum Takeoff Weight	3,590 lbs / 1,630 kg
Fuel Capacity	257 liters
Climb Rate to 1 km	In 6 minutes 30 seconds
Maximum Speed	118 mph / 190 km/h
Cruising speed	104 mph / 168 km/h
Range	479 miles / 800 km
Maximum Service Ceiling	14,635 ft / 4,600 m
Crew	Pilot and Medical Crew
Armament	None

Gallery

Illustrations by Carpaticus

Credits

Written by Marko P.
Edited by by Stan L. & Henry H.
Illustrations by Carpaticus

Sources

C. Chant. (2007) Pocket Guide aircraft of the WWII – 300 of the world’s greatest aircrafts, Grange books.
J. B. Cynk (1971) Polish Aircraft 1893-1939, Putham and Company
B. Belcarz and R. Peezkowski (2001) White Eagles: The Aircraft, Men and Operations of the Polish Air Force 1918-1939, Hikoki Publications
J. Koniarek Polish Air Force 1939-1945, Signal Publication.

PZL P.50 Jastrząb

August 23, 2018Poland, WW2Experimental, PolandKermit the Gamer

Poland (1939)
Prototype Fighter – 2 Built

The PZL P.50 Jastrząb (Hawk) entered development in 1937 as a replacement for the outdated PZL P.11 and PZL P.24 fighters. Very little was known about the aircraft until relatively recently, with only a few photographs and documents about this aircraft surviving World War II. Most of what is known at the time of writing is based on accounts and sketches from PZL engineers years after the war and mostly based on memory, which is not the most reliable form of historiographic evidence. Ultimately, the project was cancelled in March of 1939 due to dissatisfaction with its underpowered radial engine, despite an attempt being made to fit an inline vee engine to the aircraft in the form of the PZL P.56 Kania (Kite).

History

In the latter half of 1936, plans to replace all of Poland’s PZL P.11 single-engine fighters with the twin-engined PZL P.39 heavy fighter were abandoned, and the need for a maneuverable single-engine interceptor was recognized. Briefly, the PZL P.24 was considered in order to fulfill this role, but as it did not offer much of an improvement over the P.11, it was ultimately decided that an entirely new design was needed.

Wsiewlod Jakimiuk, the head of PZL’s fighter team, submitted a proposal in autumn 1936 featuring “an advanced low-wing monoplane which offered improved all-around performance and great scope for future development” (Cynk, p. 259). The aircraft resembled the American Seversky/Republic fighter designs. One of the things that Jakimiuk focused on in the design of this aircraft was to allow upgrading to larger and more powerful engines to be a simple task to accomplish at any later time.

Ultimately, after a heavily-protracted design process plagued by numerous issues, the aircraft never saw combat and only 32 airframes had been built before Poland was invaded by Germany and the USSR in September 1939, but 30 of these were not completed.

Design

This image shows Count Ciano of Italy inspecting the P.50/I. Note the cowling’s radial engine cooling system.

In the fall of 1937, the design, now called the PZL P.50 Jastrząb and powered by a British 840-horsepower Bristol Mercury VIII radial engine, was approved and two prototypes were soon built. The first prototype, called the P.50/I, was designed to take engines up to 1,200-horsepower while the second prototype, the P.50/II, was designed for engines of up to 1,600-horsepower. Both versions were to be armed with four 7.7-millimeter machine-guns in the wings although, confusingly, the few images of the P.50/I show two of these guns in the forward fuselage instead. The P.50A production version of the P.50/I was envisioned to have a top speed of 310 miles per hour (500 kilometers per hour) at 14,100 feet (4,300 meters).

The Polish Aviation Command almost immediately ordered 300 aircraft and paid for the first 100 in advance, with the first 50 expected to be delivered by September 1939. In order to speed up development The Dowty Company of Britain was contracted to build the landing gear for the prototype, while PZL and the Czech Avia company would design the production aircraft’s landing gear. Dowty delivered the landing gear over four months late, and the P.50/I Jastrząb prototype, still utilizing the Mercury engine, did not even fly until February 1939.

During the P.50/I’s initial flight trials, it was discovered that the desired performance parameters were far out of reach. The top speed at full load was only 274 mph (442 kph). It also handled low-speed turns very poorly and had a tendency to wobble at top speed. Curiously, it was discovered that the engine was unable to produce full power under any circumstances. It was not until May that it was realized that the carburettor air intake was too small. After enlarging the intake and improving the tail and wing surfaces, the aircraft’s performance was improved. In August, the aircraft finally reached its desired speed but, by the time the war began in September, the aircraft was still a long way from being ready for service. The only known photos of the P.50/I come from a visit in February 1939 by the Italian Foreign Minister, Count Galeazzo Ciano.

Developed alongside the P.50/I was the P.50/II, which had been completed in the spring of 1939 and was still waiting for an engine by the time of the invasion in September. The P.50/II differed greatly from the P.50/I, so much so that it is believed to have received a new designation just before the war began. The canopy was an all-round-vision hood, somewhat similar to the Soviet Yak-1b. The P.50/II also included provision for additional fuel tanks and a 660-pound (300kg) bomb, and two 20mm cannons were added to the wings. The two machine-guns which were in the fuselage of the P.50/I were also moved to the wings. The powerplant was supposed to be the PZL Waran radial engine, capable of up to 1,400hp, with the intended top speed of the P.50/II being 350mph (560kph). However, development of the engine was far behind schedule and it was estimated that it would not be ready before the middle of 1940. In a desperate search for a suitable engine, several different options were considered. These included the 1,375hp Bristol Hercules and the 1,400hp Gnome-Rhone 14N, again both radial engines. In the end, the Hercules appears to have been chosen, and it was around this time that the P.50/II received its new designation.

This angle of the same visit by Count Ciano shows off the two machine-guns in the forward fuselage.

There was one more derivative of the P.50, beginning in late 1938. Political upheaval was ongoing in the Polish Air Force high command, and General Ludomil Rayski, who favored radial engines, was coming under heavy criticism and was nearing replacement by General Jozef Zajac, who favored vee engines. This replacement would eventually take place in March 1939. Jakimiuk, the designer of the P.50, anticipated this shift and proposed a Jastrząb adapted to take an inline engine. The aircraft was given the designation P.56 Kania (Kite) and was to be powered by the 1,200hp Hispano-Suiza 12Y, and later by the improved 1,600hp Hispano-Suiza 12Z. However, another PZL designer, Jerzy Dabrowski, submitted a competing design bearing the designation P.62, and this design was preferred over the P.56. The P.56 was ultimately cancelled in the summer of 1939.

When General Rayski was ousted from the command of the Polish Air Force in March 1939, the P.50/I was still having severe problems. His replacement, General Zajac, canceled all production of the P.50 almost immediately. 30 P.50A airframes had begun construction at the W.P.1 plant in Okecie and, after the P.50/I began to show improvement, construction was permitted to continue on these aircraft only. Because of the unsatisfactory results of the Mercury engine, plans were made to power the very first of these production aircraft with the 870hp Gnome-Rhone 14Kirs, and this aircraft was very close to being ready in September 1939. This was to be a sort of test aircraft for an improved version of the P.50A, the P.50B Jastrząb B. There were also plans to mount the 1,100hp Gnome-Rhone 14K or the 1,000hp Pratt & Whitney R-1830 Twin Wasp, although these never came to fruition.

“The Hawk Which Would Never Prey”

On September 5th, 1939, the PZL factory in Warsaw was evacuated. Test pilot Jerzy Widawski attempted to escape with the P.50/I prototype, but was accidentally shot down by Polish anti-aircraft guns. Five pre-production P.50A airframes and the P.50/II prototype, including the aircraft intended to be equipped with the 870hp engine mentioned earlier, were moved out of the Okecie plant on September 3rd. These were captured by the Germans and scrapped in 1940, bringing a final end to the P.50 Jastrząb project.

Variants

PZL P.50/I Jastrząb – Initial prototype of the PZL P.50 series. Powered by an 840hp Mercury VIII engine, the top speed was intended to be 310 mph, but it only ever reached 275 mph. Armament was four 7.7mm machine-guns, with two in the forward fuselage and two in the wings. One produced, first flew in February 1939.
PZL P.50A Jastrząb A – Planned production version of the PZL P.50/I. 300 were ordered, but only 30 built, all incomplete by the time of Polish capitulation. Fuselage was changed to a razorback rear, akin to the American P-47. It is unclear whether the fuselage machine-guns were moved to the wing, as documents imply they were but sketches of the aircraft still show them in the fuselage. Top speed had been improved to 310 mph (500kph).
PZL P.50B Jastrząb B – Planned development of the P.50A with a more powerful radial engine. One P.50A was planned to fit an 870hp Gnome-Rhone 14Kirs engine as a sort of testbed for the P.50B, but that is all that is known about this variant.
PZL P.50/II Jastrząb II – Second prototype developed alongside the P.50/I prototype as an all-around upgraded version. The canopy was changed. A 660 lbs (300 kg) bomb was added, along with two 20mm cannon to the wings. The engine was upgraded to the 1,400hp PZL Waran engine, giving a projected top speed of 350 mph (560 kph) . Only one was produced, without the engine, and never flew.
PZL P.56 Kania – Planned development of the P.50A Jastrząb A using either a 1,200hp Hispano-Suiza 12Y or 1,600hp Hispano-Suiza 12Z inline Vee engine. None produced.

Operators

Poland – 300 copies of the P.50A type were ordered, with only 30 incomplete airframes + 1 P.50/I prototype produced. Did not see service. A single P.50/II prototype also existed, but the type was never ordered.

PZL P.50A Jastrząb A Specifications
Wingspan	31 ft 9.875 in / 9.7 m
Length	25 ft 3.125 in / 7.7 m
Height	8 ft 10.25 in / 2.7 m
Wing Area	208.83 ft² / 19.4 m²
Engine	One 840hp (648.8kW) Bristol Mercury VIII nine-cylinder radial engine
Empty Weight	3,748 lbs / 1,700 kg
Maximum Takeoff Weight	5,511 lbs / 2,500 kg
Maximum Speed	310.6 mph / 500 kmh
Range	466 mi / 750 km
Maximum Service Ceiling	14,107 ft / 4,300 m
Crew	1 pilot
Armament	Four 7.7mm KM Wz 36 machine-guns mounted in the wings OR two in the fuselage and two in the wings Provision for an unknown weight of bombs, possibly 220.5lbs (100kg), to replace two wing machine-guns