SPAD S.A1-S.VII.C1


In frontline service the Spads’ cooling system demonstrated two major shortcomings. At high ambient temperatures they quickly overheated; when subjected to low temperatures, they tended to get excessively cold. The overheating problem was tackled ‘in the field’ by drilling extra cooling holes in the cowling and removing the engine side panels. The overcooling problem was, in turn, addressed by limiting the active surface of the radiators, various solutions being tried (even a solid metal cover). Eventually, regulating the cooling airflow by means of radiator shutters proved to be the most efficient solution. After experimenting with many different arrangements, a set of seven vertical shutter bars became standard.
In November 1916 the STAé16  suggested the Spad VII’s wings should be modified by reducing their span and increasing their chord, to give a bigger wing area of 19 m². However, since the performance of the modified aircraft was only slightly improved17, further tests were discontinued in December 1916. Another modification ordered by the STAé was a ‘flatter’ wing, which used the standard geometry. The ‘flat wing’ was tested in February 1917 but there are no indications that it ever made it to serial production.

Spad   zdj7

By March 1917 several modifications were introduced in response to operational service experience. The most important were the replacement of the aluminum fuselage bracing components with steel alternatives, some strengthening of the engine bearers and the internal strengthening of the fuselage framework by means of steel cables. In summer 1917 Spad S.VII.C1 was modified for the ground-attack role. Some aircraft were fitted with racks for carrying 10 kg (22 lb) Anilite bombs. The racks were mounted on the rear undercarriage legs.
The Spad S.VII.C1 powered by the Hispano-Suiza 8Aa proved to be slower than its main adversaries, the German Albatrosses and Fokkers. Hence, in the spring 1917 Birkigt modified the Hispano-Suiza 8Aa engine, increasing its compression ratio from 4.7:1 to 5.3:1. This increased power output to 133 kW (180 hp) at 1,800 rpm. The upgraded engine was rushed into production under the designation ‘Hispano-Suiza 8Ab’. The increase in revolutions required a decrease in propeller pitch. By April 1917, the Hispano-Suiza 8Ab had become the standard engine on all production Spad VIIs. The first pilot to fly the re-engined Spad S.VII.C1 in combat was Georges Guynemer, who scored 19 aerial victories in it.

Spad   zdj8


The production of Spad S.VII.C1s increased only slowly. Instead of the expected 800, only 268 examples were delivered to the French Air Force by 25th February 1917. Since it was planned to withdraw all the sesquiplane Nieuports (leaving only the Nieuport 28C1) from frontline units by the end of 1917, something had to be done about the poor production output of Spads. They were in urgent demand not only by the French, but also by other Allies (Great Britain, Italy, Russia and Belgium). There were two solutions: expand the already existing factories and start license production. In France, several companies were contracted to produce Spads: Bleriot Aeronautique, Les Ateliers d’Aviation L. Janoir, Kellner et ses Fils, Construction Aeronautique Edmond de Marçay, L’Atelier de Construction d’Apareils d’Aviation Roger Sommer, Les Ateliers de Construction Regy Freres, Societe d’Etudes Aeronautiques (SEA) and Gremont. Abroad, license manufacture was started in Russia by the Duks (Aktsionyernoye Obschestovo Duks) company in Moscow, and in Great Britain by Mann, Egerton & Co. Ltd from Norwich and L. Blériot (Aeronautics) Ltd Brooklands (later renamed Blériot & Spad Aircraft Works). Modifications and improvements incorporated into the basic design during the subsequent production included enlarged ailerons and wing area. Some Spad VIIs were equipped with a photographic camera of 26 cm focal length for reconnaissance duties. The camera was mounted on the port side of the fuselage aft of the pilot’s cockpit in a specially designed recess. It was accessible through a removable plywood panel. The ‘recce’ Spads were marked with PHOTO lettering on either side of their fuselages.
Like Nieuports, Spad VIIs were modified to combat enemy airships and observation balloons. For this purpose they were armed with Le Prieur unguided rocket missiles, fired from tubular launchers attached to the mid-bay struts. To prevent damage from the rocket exhaust gases, metal sheathing was used to protect part of the lower wing area under the strut. Spads produced in Great Britain were slightly different from their counterparts manufactured in France. Noteworthy differences included the installation of un-louvered engine cowling panels (in place of the original design’s louvered side panels) and a hood-like fairing over the breech of the Vickers machine gun in front of the pilot’s cockpit (in Spads produced by Blériot & Spad at Addlestone). The cumbersome fairing was expected to make it easier for the pilot to clear jams, as it was intended to serve as a windshield. However, the fairing was not transparent and significantly impaired the pilot’s view forward; it was therefore usually removed. The Addlestone plant attempted to re-engine the Spad with a 147 kW (200 hp) Hispano-Suiza engine, and to augment its onboard armament by installing twin machine guns. Nevertheless, tests were abandoned in June 1917, most probably due to the fact that the Spad S.XIII.C1 was already coming down the pipeline. Another British initiative was to mate a Spad S.VII to a 147 kW (200 hp) Wolseley Viper engine. In general, the performance of British-built Spads was found inferior to that of the French-built aircraft. Many aspects contributed to this situation, mainly related to production technology and the materials used. For example, the Spads produced by Mann, Egerton & Co. Ltd were 20 kph slower than the French Spads.

kolor

Pilots who flew the Spad S.VII.C1 in combat generally considered it a good aircraft, very rugged, with decent manoeuvrability, but flawed in its weak armament. By summer 1916 a single machine gun was a serious drawback. Two machine guns, which at that time were becoming standard on German fighters, offered substantially greater firepower. The British mounted an additional Lewis machine gun on top of the upper wings of their Spads (slightly offset to starboard) firing over the propeller arc. This modification augmented the firepower, but at the cost of increased drag. The total production output of Spad VIIs is estimated at 3820 aircraft, including approximately 3500 built in France, 220 in Great Britain and 100 more in Russia.

 

 

Read more…

ss 07 okladkaaa

  • Recommended - Aircraft

Gloster Gladiator Mk I and II
Gloster Gladiator Mk I and II Contact! There they were, a curiously lopsided Squadriglia of...
PZL P.24 A-G
PZL P.24 A-G Although built in fewer numbers than the  PZL P.11, the PZL...
The Habsburgs’ Wings 1914 vol 1
The Habsburgs’ Wings 1914 vol 1 The Great War (World War I 1914-1918) has been in the public...
Yakovlev Yak-1 Vol. II
Yakovlev Yak-1 Vol. II The pursuit of better performance continued until all the po...