J.Davilla, A.Soltan French Aircraft of the First World War (Flying Machines)

Caudron C.21

  The Caudron C.21 was an early attempt to meet the Bn 2 requirement of 1917. The C.21, like the G.6 and unsuccessful R.5, featured a conventional fuselage with two 80-hp Le Rhone engines mounted between the equal-span biplane wings. The abbreviated nose was reminiscent of the prototype G.6. The aircraft was designed by Caudron's chief engineer, Paul Deville. Testing of the C.21 began in November 1917. However, as with the R.10, the engines were not sufficiently powerful; they were subsequently replaced by two 120-hp Le Rhones. The new plane was designated the C.22. Postwar, the C.21 was developed into an "aerial limousine." It was labeled the "Monsieur-Madame" and had seats for the chauffeur-pilot and a mechanic-footman in front. Both the crew had open cockpits, but the passengers had an enclosed cabin for two. This new type was labeled the Caudron C.33.


Caudron C.21 Two-Seat Night Bomber with Two 80-hp Le Rhone Engines
   Wing surface area was 39 sq. m
   Empty weight was 1,140 kilograms; loaded weight 1,480 kg
   Max speed 100 miles per hour at 4,000 m; climb to 4,000 m in 22 minutes; endurance 3 hours
   One built



Caudron C.22

  The Caudron C.22 was a follow-on to the C.21 and, like its predecessor was designed by Paul Deville to fulfill the requirement for a medium bomber capable of tactical attacks with 500 kg of bombs. Other aircraft designed to this specification included the Voisin 11, Farman F.50, Bernard A.B.1, and Breguet 16.
  The C.22 was a conventional biplane initially powered by two 120-hp Le Rhone 9Jb engines. Two 130-hp Clerget rotary engines were later fitted, presumably to improve performance. The C.22 Bn2 first flew in November 1917. It could carry six 120-mm and three 155-mm bombs. As with other Bn2 aircraft, defensive armament was light, in this case a single machine gun; the Bn2 aircraft were expected to use the cover of night as the primary means of defense.
  The C.22 failed to meet the requirements of the Bn2 category because it was too slow and poorly armed. Further development was abandoned and the Breguet 16 and Farman F.50 were selected for series production.


Caudron C.22 Two-Seat Night Bomber with Two 120-hp Le Rhone 9Jb Engines
   Span 18.54 m; length 8.30 m; height 2.52 m; wing area 53 sq. m
   Empty weight 950 kg
   Maximum speed: 141 km/h at 3,000 m, ceiling 3,352 m
   Armament: six 120-mm and three 155-mm bombs, one machine gun.
   One built



Caudron C.23

  A further development of the C.21 and C.22, the C.23 was to prove more successful than its predecessors. The C.23 BN3 was designed to meet the specification for a night bomber with two or three crew members, a bomb load of 1,200 kilograms, and a range to permit attacks on Berlin. Other aircraft competing for the BN3 orders were the Caproni BN3 (Caproni Cap. 5), Letord 9, Delattre BN3, Voisin 12, Renault O2, Delattre BN3, and Sikorsky BN3.
  The Caudron C.23 first flew in February 1918. It was of similar configuration to the previous C.21 and C.22. The engines were two 260-hp Salmson CU-9Z water-cooled radials. The aircraft was a biplane with unequal span wings supported by 16 struts. Each wing had two rectangular spars made of three strips of spruce and covered with two strips of steel. The wings were covered in flax and were camouflaged on top and dark brown underneath, the struts were made from spruce or Oregon pine in three segments which were wrapped in strips of ash for added strength. At equal intervals metal strips were used to band the struts for additional strength. Sheet metal was fashioned for the ends of the struts where they were attached to the wing. The ailerons were on the top wing only and had a span of six meters. The tail had a rudder and fixed fin. The rudder had three vertical ribs made of wood, was covered with steel, and attached directly to the fuselage. The horizontal stabilizers were made of two spars supported by ribs and the leading edge was covered in spruce.
  The fuselage was constructed from four longerons made of ash and spruce. The nose was flattened, while the cross-section of the mid fuselage was rectangular. The fuselage formers were made of pine strengthened by diagonal bracing wires. The pilot and co-pilot were seated side-by-side ahead of the wing struts. There was a nose turret and a second turret located behind the wing. The lance bombs were carried inside the fuselage. There was a passage between the bomb bay and the front the fuselage. The engines were mounted on sheet metal which was bolted to the upper and lower wing spars. The fuel tank was located behind the engine and was divided into five compartments internally to prevent the fuel from shifting inside the tank during flight. The radiators were supported on an aluminum collar bolted to the base of the motor. The oil tank was located above the fuel tank. Under each engine was an undercarriage of N-configuration with an oval cross section. There were twin wheels, between which was a landing skid used for braking. The skids were made of ash. The axles were mounted on bungee chords. The tail skid was made of ash with a metal tip and was attached to the rudder axle.
  The aircraft took off and climbed at a speed of 120km/h. Cruising speed was 140 km/h and the ideal descent speed was 120 km/h. The aircraft was landed at 100 km/h. Pilots were instructed that, should the C.23 enter a spin, they were to apply opposite rudder to stop the spin and then re-establish control after the ailerons became effective. If the aircraft should stall the preferred solution would be to allow the C.23 to build up speed before attempting any correcting maneuvers.
  The plane met the BN3 requirements and 1,000 were ordered. Although the design was to prove successful and 54 C.23s had been accepted by the Aviation Militaire before the Armistice, not a single example reached units in time to see action. Postwar, CAP 115 relinquished its Caproni bombers for C.23s and was redesignated C 115. These bombers served with the 22nd RAB (Nuit) at Luxeuil. Crews found the type to be seriously underpowered and it maneuvered poorly. The C.23s were replaced by the superior Farman F.60 in February 1920.
  Another version of the C.23 was under development in April 1918. It was to have been powered by two 600-hp Salmson engines and, had it been successful, might have eliminated many of the problems found in the production aircraft. Another C.23 was tested with two 300-hp Hispano-Suiza engines.
  Postwar, the C.23 was developed into an airliner and initiated service from Paris to Brussels on 10 February 1919. A version designated the C.23bis had an enclosed cabin and could carry 15 persons.


Caudron C.23 Three-Seat Heavy Night Bomber with Two 260-hp Salmson Cu-9Z Engines
   Span 24.47m; length 12.98 m; height 3.45 m; wing area 106 sq. m
   Empty weight 2,341 kg; loaded weight 4,170 kg; payload 500 kg or an 800 kg torpedo
   Maximum speed: 144 km/h at 1,000 m; 140 km/h at 2,000 m; climb to 2,000 meters in 20 minutes 37 seconds
   Ceiling 4,500 m; endurance 4 hours; range 700 km
   Armament: 600 kg of bombs

Projected C.23 with 600-hp Salmson Engines
   Wing area 100 sq. m
   Loaded weight 3,707 kg; payload 800 kg
   Max speed: 170 km/h at 4,000 m; climb to 4,000 m in 25 minutes; endurance 5 hours



Caudron CRB

  The CRB (the reason for the unusual designation is unclear) was a twin-engine bomber apparently initiated as a design study for the RFC in 1917. It was to have been equipped with two 200-hp Hispano-Suiza engines. The aircraft was never completed.



Caudron Heavy Bomber Project

  A heavy bomber is believed to have been undergoing construction in 1917. It was to have had a bomb load of 600 kg, and the engines were to be 340-hp Salmsons. Apparently the aircraft was never completed.