Lublin R-VIII
The Lublin R-VIII was the Polish bomber - reconnaissance aircraft and seaplane, designed in the late-1920s in the Plage i Laśkiewicz factory in Lublin. It was the first own design of Plage i Laśkiewicz, and the first with the name Lublin.
Development
The aircraft was designed in answer to a request of the Polish Air Force for a single-engine reconnaissance-bomber airplane. The works started in 1926. The main designer was Jerzy Rudlicki (letter "R" in a designation was for his name). The prototype R-VIII was flown in March, 1928. It was fitted with a Farman WI 550 hp engine, but the test showed, that it was insufficient. In July 1928 the second prototype was completed, with Lorraine-Dietrich 18Kd 650 hp engine. In August it flew in the Aviation Contest of the Little Entente and Poland. It achieved the best result in a trial of carrying payload (1024 kg to an altitude of 5000 m).
In 1929, the Polish Aviation Departament ordered 4 serial aircraft, with a designation R-XVIIIa. They were built in early 1930. One was fitted with Lorraine-Dietrich engine, the rest with Hispano-Suiza 12Lb 650 hp. There was not ordered greater series, because the aircraft had good performance when carrying limited payload and fuel reserve, what limited its range as well. When it carried more bombs, or maximum fuel amount, its performance lowered.
The prototypes and serial planes were used by the Polish Air Force for a short time. In August-September 1930, three R-VIIIa flew in the Aviation Contest of the Little Entente and Poland, taking the mediocre 7th and 9th place. During service, two R-VIII with Lorraine-Dietrich engines crashed - in 1930, and possibly in 1931.
In 1932, the existing R-VIIIs were converted to floatplanes for the Polish Navy. The first prototype received Lorraine-Dietrich engine and was designated R-VIII bis (aircraft number 801). Two planes with Hispano-Suiza engines, were designated R-VIII ter (numbers 802 and 803). The fourth aircraft was broken into spare parts. Maximum speed of the floatplane variant lowered to 200 km/h.
The R-VIII floatplanes were used by the Polish Naval Aviation Squadron (MDLot) in Puck from 1933, in a long reconnaissance escadre. From 1938, they were assigned to a training, and were scheduled for withdrawal from service. They survived until the Polish September Campaign in 1939, but R-VIII bis had its engine removed by then. After the first German unsuccesfull air raid on naval aviation base in Puck on September 1, all floatplanes were evacuated from Puck to Hel Peninsula (the bulk were Lublin R-XIIIs). Since R-VIIIs were quite obsolete by then, they were not used in combat. They were anchored on sea near Chalupy on Hel Peninsula, where they were bombed by Stukas on September 8.
Description
Wooden construction biplane, conventional in layout. Fuselage rectangular in cross-section, plywood covered. Wings canvas and plywood covered, upper wing of greater span. Crew of two, sitting in tandem in an open cockpit, with twin controls. Conventional fixed landing gear, with a rear skid, or two Short floats.
The pilot had one fixed 7.7 mm Vickers machinegun with interrupter gear, the observer had twin 7.7 mm Lewis machineguns on a ring mounting. Bomb load: in bomber variant unknown, in seaplane variant - 300 kg.
Engine:
- 18-cylinder inline W engine Lorraine-Dietrich 18Kd 650 hp power, 740 hp take-off power, water cooled (second prototype, one serial R-VIIIa, R-VIII bis)
- 12-cylinder inline V-12 engine Hispano-Suiza 12Lb 650 hp power, 760 hp take-off power, water cooled (three serial R-VIIIa, R-VIII ter)
Two-blade propeller, 4.4m diameter. Fuel tank 1200 liters in the fuselage, could be dropped in case of fire emergency. There could be mounted additional fuel tank, increasing range to
Specifications (R-VIIIa, Lorraine-Dietrich)
General characteristics
- Crew: Two - pilot and observer
- Length: 11.12 m
- Wingspan: 17 m
- Height: 4.5 m
- Wing area: 76.4 m²
- Empty: 2457 kg
- Loaded: 3500 kg
- Maximum takeoff: 4300 kg
- Powerplant: 1x 740 hp
Performance
- Maximum speed: 225 km/h
- Range: 600 km
- Service ceiling: 5,770 m
- Rate of climb: 5.25 m/s
- Wing loading: 45.8 kg/m²
- Power/mass: kW/kg, hp/lb
Related content
Related development: Lublin R-IX
Comparable aircraft: Amiot 122 - Heinkel He 60
Designation sequence: R-VIII - R-IX - R-X - R-XI - R-XII - R-XIII R-XIV