W.Green, G.Swanborough The Complete Book of Fighters

SPAD SF

  The SPAD SF represented yet another attempt by the firm to design a fighter with a clear field of fire for the gunners. The SA series had used a pulpit design, which placed the gunner in a precarious location and partly for this reason had been only a limited success. The type SF, designed in February 1916, was probably intended to rectify this problem by moving the gunners as far away from the propeller as possible. The design featured a fuselage with two "tails," one in the front and one in the rear. This seems to have meant that it had a canard arrangement in the front and a second tail in the rear. It has been described in a contemporary publication as literally two biplanes joined "nose-to-nose" at their engines. There were machine gun positions in the nose and tail, which gave both gunners a clear field of fire. The two rotary engines were buried in the fuselage and drove two propellers located in the center of the fuselage (possibly in a similar arrangement as that used on the Dufaux fighter). The pilot's cockpit was also located in the fuselage. It is not known if this machine was ever completed or flown; the concept of a canard fighter with engine and propellers located in mid-fuselage was not further developed by the SPAD firm.


  

SPAD SG

  The SPAD SG was a modification of the SA.2 series. The primary difference was that the SG had a fixed Hotchkiss infantry machine gun in the nose (although on the prototype four dummy machine gun barrels had been fitted). The SG also dispensed with the gunner, carrying only the pilot and a machine gun. The nacelle had been extensively modified to allow the Hotchkiss to be fitted. As there was no gunner, the gun was aimed by the pilot. The engine was a 110-hp Le Rhone 9J.
  Photographs of the prototype SPAD SG show it was otherwise quite similar to the SA series, although the pulpit/nacelle was considerably shorter and of circular cross-section. The engine was the same as the SA.1, an 80-hp Le Rhone. The prototype SG appears to have been a modification of a standard SA.1, although this has not been established.
  The actual SG, which was significantly different from the prototype, was evaluated in April 1916. The deletion of the second crewman enabled a more powerful armament to be carried and the aircraft might have proved useful in the ground attack role; it was not likely to be very effective as an interceptor given the inferior performance of the SPAD SA series. It may have been felt that the Voisin 4 "canons" were adequate for the role the SG was intended to fill, as no orders were placed for the SPAD design. Some sources suggest that the Type SG may have been given the STAe designation SPAD 9.
  At least one Imperial Russian Air Service SA.4 was modified in similar fashion to the proposed SPAD SG.


SPAD SG Single-Seat Fighter with 110-hp Le Rhone 9J
   Wing area 18.58 sq. m
   Maximum speed: 161 km/h at 2,000 m; 154 km/h at 3,000 m; climb to 2,000 m in 7.25 min.; climb to 3,000 m in 11.5 min.
   Armament: one fixed Hotchkiss machine gun with 1,000 rounds
   One built