The Lublin R-XVIII was the designation for a series of multi-engined bomber designs of the early 1930s, none of which entered production.
In 1931 the Department of Aeronautics asked for designs for a new multi-engined day and night bomber, which was to replace the increasingly dated Fokker F.VIIb-3m. They set an ambitious set of requirements – the new aircraft was to use domestically available raw materials, carry heavy defensive armament, reach a top speed of 155.3mph, be capable of operating from unprepared fields, and be cheep to both build and maintain.
Jerzy Rublicki was given the task of producing a Lublin design to fill this requirement. His first design was for a three engined biplane, using welded steel tubes for the fuselage structure and wooden wings which would only use one type of rib to reduce complexity. The design would be powered by three 500hp Bristol Jupiter radials, with the third engine mounted in a nacelle in the upper wing, with a gun position at the back of the nacelle. Versions with fixed and retractable undercarriages were produced.
Later in 1932 he abandoned this idea in favour of a smaller, lighter twin engined biplane, using two 650hp Bristol Pegasus or Gnome-Rhone radial engines, a fixed undercarriage, and a ‘V’ shaped tail that was then under development at Lublin. Some bombs could have been carried on Swiatecki racks inside the lower wing’s centre section.
Late in 1933 the Polish Air Force examined the various competitors. The Lublin design was judged not to be advanced enough, and instead a modified version of the P.Z.L 30 civilian transport was chosen. This was a twin engined biplane, although the bomber version, which eventually emerged as the L.W.S.4, doesn’t look terribly advanced for the period. However the Polish aviation authorities had already expressed a dislike of the ‘V’ wing, so it isn’t surprising that they also chose against the R-XVIII.
Engine: Two Bristol Pegasus or Gnome-Rhone radials
Power: 640 each
Empty Weight: 4,188lb
Maximum loaded weight: 8,818lb
Maximum Speed: 161.5mph
Cruising Speed: 130.4mph
Range: 621 miles
Guns: 2,205lb to 3,307lb internally in fuselage and lower wing centre section
Bomb load: four gunnery positions in nose, tail and rear of engine nacelles, each capable of carrying one or two machine guns