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

Borel C1

  The Borel C1 was designed to meet the C1 specification of 1918, which called for a single-seat fighter to be armed with two machine guns (either 7.7-mm or 11-mm) synchronized to fire though the propeller. An alternative armament of a machine gun and a 37-mm cannon was acceptable. Two additional machine guns (which were to be mounted in a turret and manned by a second crewman) were considered desirable. This later version was called a single-seat protege. A photographic reconnaissance version was planned.
  Two aircraft were designed to meet this specification: the SPAD 20 and the Borel C1 Flandre. The Borel design was to have been powered by a 300-hp Hispano-Suiza 8F. The aircraft was under development at the time of the Armistice. Shortly thereafter a decision was made to delay work on the type until the Borel-Boccaccio C2 (Type 3000) had been flight tested. However, it seems that development of the Borel C1 was never completed.



Borel-Boccaccio Type 3000 (C2)

  The C2 specification of 1918 called for a two-seat fighter carrying a single synchronized machine gun or cannon, two machine guns in a turret behind the pilot, and a machine gun fitted to fire downward. The payload as to be 375 kg, maximum ceiling was to be 8,000 meters with a service ceiling of 5,000 meters, and a maximum speed of 220 km/h was required. There were many aircraft submitted to meet this specification, three of which used the 300-hp Hispano-Suiza 8Fb engine: the Hanriot-Dupont HD.5, the B.A.J. C1, and the Borel-Boccaccio C2.
  Work on the Borel design was completed by March 1918, wind-tunnel models having been used to help develop the basic shape. The aircraft was not completed until 1919.
  The Borel-Bocaccio Type 3000 was a two-bay biplane with dihedral on the upper wing only. The interior structure included a latticework arrangement for strength. The leading edges of the wings were covered in plywood and the trailing edge was made of wire. Ailerons were on the lower wing only. The engine mount consisted of two supports made of walnut and were padded with leather to decrease vibrations. The motor supports were reinforced by sheet metal. An Odier starter was mounted on the engine. A large access panel allowed the carburetor, magnetos, starter, and plugs to be easily serviced.
  The fuselage was comprised of four longerons of ash and spruce interconnected by a latticework of spruce and piano wire. There were two fuel tanks which could be jettisoned in the event of a fire. The oil tank held 15 liters and was exposed to the air. The rear of the fuselage was made entirely of wood and the tailskid was made of ash. There was a ventral radiator between the landing gear struts. The aircraft had space tor two cameras under the pilot's seat. When the aircraft was flown as a single sealer the guns of the rear turret would have two machine guns fitted and could be fixed to fire to the front of the aircraft, above the wing. The fuselage was streamlined, and the Hispano-Suiza 8Fb and the fixed Vickers 7.7-mm machine gun were closely faired. A large spinner was fitted. There were prominent cutouts on the trailing edges of both the upper and lower wings to facilitate the crew's view. Armament consisted of one Vickers 7.7-mm machine gun (with the option for a second). There was a T.O.3 ring mount to which two 7.7-mm Lewis guns could be fitted. A third Lewis could be fitted to fire through the floor. Thus the Borel-Boccaccio Type 3000 met the armament requirement lor the C2 class. Static testing revealed that the airframe was quite sturdy with a load factor of seven.
  Modifications after initial flight testing included replacing the ventral radiator with two Lamblin radiators mounted on the undercarriage. The exhaust manifolds were shortened, and the tailplane bracing was strengthened by the addition of two struts.
  The type performed well and easily exceeded the C2 requirements. However, the SPAD 20 had been completed earlier (having been flown in August 1918) and was chosen for series production.


Borel-Bocaccio Type 3000 Two-Seat Fighter with 300-hp Hispano-Suiza 8Fb
   Span 11.4 m; length 7.095 m; height 2.65 m; wing area 33 sq. m
   Empty weight 897 kg; loaded weight 1,315 kg
   Maximum speed:
   sea level 242 km/h
   1,000 m 260 km/h
   2,000 m 237 km/h
   4,000 m 230 km/h
   Climb to:
   1,000 m 2 min. 47 sec.
   2,000 m 6 min. 29 sec.
   4,000 m 15 min.
   6,000 m 25 min. 53 sec.
   Ceiling 7,500 m; range 500 km; endurance 3 hours
   Armament: two fixed 7.7-mm Vickers machine guns; one or two 7.7-mm Lewis guns on a T.O.3 gun mount.
   One built