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

Bleriot 73/74/75/76

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  The Bleriot 74 was initially planned as yet another attempt to meet the requirements for a night bomber. Other aircraft produced to meet this requirement included the Voisin 12, Letord 9, Farman F.50 and F.60, Caudron C.23, Breguet 16 Bn2, S.I.A. Bn2, and the Sikorsky Bn2.
  Like its predecessors, the Type 74 was powered by four 300-hp Hispano Suiza 8Fb engines closely grouped around the fuselage to reduce asymmetric thrust problems with one engine out. The fuselage was mounted on the lower wing. The landing gear of the types 71 and 73 was retained. The bombardier was to be seated in the bottom of the aircraft with a trapdoor underneath the aircraft to permit maximum visibility. A machine gun was also to be located in this position. A machine gun turret was to be located beneath the rear of the aircraft. There was extensive use of duralumin in the support structure which reduced the weight of the aircraft. The end of the war resulted in the Bleriot firm's decision to redesign it as an airliner. Andre Herbemont took the wings of the proposed Bleriot 74 and designed an entirely new fuselage partly of biconvex shape and accommodating 56 passengers.
  During testing at Villacoublay on 22 January 1920 oscillations ruptured the tail and the Bleriot 74 crashed, killing its pilot, Armand Berthelot, an ace with 11 victories.
  The Type 75, also called the Aerobus, was the same plane as the Bleriot 74 but had a new wing that had a pronounced dihedral. The fuselage was lengthened by 3 meters over the Type 74 and the center vertical tail surface was enlarged. Tested by Jean Casale, it had a good performance. However, no orders were forthcoming from the airlines because of the availability of far cheaper war surplus planes.
  The Bleriot 76, although under study in 1920, warrants mention here because it was designed to meet the wartime BN 4 specification and was a development of the Bleriot 75. The bomber had the same engine arrangement as the Types 67, 71, 73, and 74, but the lower engines were located farther outboard than the upper engines. The Type 76 had slightly swept-back wings and a much thicker monocoque fuselage. The engines were the same four 300-hp Hispano Suiza 8Fbs. The undercarriage consisted of a pair of massive wheels; apparently Herbemont had planned later to modify the undercarriage so that it would be retractable. As with so many of the BN 3/4 bomber designs, the Bleriot 76 design was not selected for production and remained a project only.


Bleriot 74 Heavy Bomber/Airliner with Four 300-hp Hispano-Suiza 8Fb Engines
   Span 27 m; length 15.40 m; height 6.40 m; wing area 148.6 sq. m
   Empty weight 3,800 kg, payload 2,250 kg, loaded weight 7,550 kg, including 1,600 liters of fuel and 120 liters of oil
   Maximum speed: 140 km/h, endurance 6 hours 20 minutes One built

Bleriot 75 Airliner with Four 300-hp Hispano-Suiza 8Fb Engines
   Span 27 m„ length 18.3 m, height 6.4 m, wing area 144 sq. m
   Empty weight 3,800 kg. loaded weight 7,500 kg
   Maximum speed: 155 km/h. ceiling 4,000 m
   One built

Bleriot 76 Heavy Bomber Project with Four 300-hp Hispano-Suiza 8Fb Engines
   Estimated wing span 27.0 m, length 20.85 m, height 6.75 m
   Project only