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

Tellier T.4

  The French Navy decided it needed a flying boat capable of carrying a heavier payload and issued a new specification calling for a payload of 1.000 kg while maintaining the same performance as the T. 3 and HB.2 flying boats. Unfortunately for the seaplane manufacturers, the 450-hp and 500-hp engines manufactured in France were reserved for the SPAD series of fighters.
  Tellier responded to this requirement by designing two different aircraft: the T.4. which was essentially aT3 fitted with the more powerful 350-hp Sunbeam engine (a water cooled V-12 Maori), and the T.5. which had two Hispano-Suiza engines mounted in tandem.
  The T.4 required few changes to the standard T.3 aside from strengthening the engine supports to carry the heavier engine. The T.3 had experienced structural failures, and Tellier attempted to remedy this fault by strengthening the fuselage behind the wings. Other changes included a redesign of the bow and revision of the wings and tail. The hull had two steps composed of three watertight compartments, each of which had a 10 cm inspection hatch. The hull was made of three layers of mahogany from the nose to the first step. From first step to the second step the fuselage was constructed of two thicknesses of plywood. The remainder of the fuselage was also made of plywood, but of decreasing thickness. There was a position for a gunner in the nose, and two seats in the main cockpit just ahead of the bottom wing. The fuel tanks, which carried 620 liters of fuel, were located just behind the pilot's cockpit. There was a Chausson radiator and a Letombe starter. The wing structure was almost identical to the preceding T.3 and T.6. The wing spars were metal tubes held in place by piano wire on which the ribs (made of ash reinforced with plywood) were placed. The wing structure was covered in linen with Emaillite coating. The upper wing was fitted with ailerons and the lower wing had a marked dihedral. The stabilization floats were attached to the lower wing. The wings were supported by 16 metal struts. A horizontal "Y" of extruded steel connected the trailing edge of the upper wing to the upper part of the tail. A post connected the rear part of the hull to the struts connecting the upper wing and tail; this served to make the Y-strut more rigid. This structure was, in turn, reinforced by numerous bracing wires. Tellier applied for a patent for this system.
  The aircraft was completed by May 1917 and flight testing began in late December. George Duick made the first flight carrying a ton of ballast. In early 1918 the T.4 was dismantled and sent to Saint Raphael for evaluation by the Aviation Maritime.
  The Aviation Maritime requested that newer seaplane designs incorporate folding wings to make storage at its naval air stations easier. The prototype T.4 had fixed wings but was modified to meet this new requirement. The modifications included changing the wing struts which were canted inwards to a vertical orientation; the dihedral and incidence of both the upper and lower wings remained unchanged. The center struts were split and the wings were hinged to pivot around them. The span of the folded wings was 8.7 meters, and the wings could be folded rapidly without need to adjust the rigging.
  The airplane was able to carry the specified 1,000 kg payload; when the Navy tested the machine they found it could carry a 1,504 kg payload. They were suitably impressed by this achievement, and the T.4 was ordered into production. However, the Navy made plans to equip T.4s with other engines, including the 340-hp Panhard 12C, the 400-hp Liberty 12A, and the 370-hp Lorraine 12Da. However, as far as can be determined these engines were never fitter to Tellier T.4s.
  The aircraft were used from French naval bases on the Atlantic and Africa and superseded the T.3s then in service. They remained in front-line service until 1922.


T.4 Two-Seat Patrol Flying Boat with 350-hp Sunbeam
   Span 23 m; length 14.750 m; height 4.10 m; wing area 84.50 sq. m
   Empty weight 2,100 kg; loaded weight 3,257 kg; payload up to 1,350 kg
   Performance (at a total weight of 3,100 kg); maximum speed: 80 knots; climb to 500 m in 4 minutes 15 seconds: climb to 1,000 rn in 8 minutes 27 seconds; climb to 2,000 m in 19 minutes 13 seconds
   Performance (at a total weight ol 3.7 32 kg): climb to 500 m in 5 minutes 45 seconds: climb to 1,000 m in 13 minutes 23 seconds; climb to 2,000 m in 35 minutes and 40 seconds: endurance 5 hours
   Armament; one 7.7-mm machine gun in the nose and four Corpet lance bombs



Tellier T.5

  The Tellier T .5 was designed to meet the French navy's requirement for a flying boat capable of carrying a 47-mm cannon and 300 kg of bombs, a considerably heavier payload than the Tellier T.3. As noted above, it was designed to the same specification as the T.4 but used two Hispano-Suiza 8B engines mounted in tandem rather than the single Sunbeam engine of the T.4. It was intended io use these aircraft in the antisubmarine role where the cannon could disable a submarine and then bombs could destroy the vessel once it had been immobilized.
  The T.5 was considerably larger than the previous Tellier flying boats. It was a biplane with unequal span wings and had the wing/hull/tail system of support struts that were used on the T 4. The hull had a position for a gunner in lhe nose and two seats in the main cockpit just ahead of the bottom wing. The fuel tanks, which carried 620 liters, were located just behind the pilot's compartment. The aircraft also had floats underneath the bottom wing. The T.5 was later modified to have folding wings (for further details see the entry for the T.4). The two 250-hp Hispano-Suiza engines were uncowled and mounted back-to-back beneath the upper wing. Two Chausson radiators were mounted between the forward engine and upper wing and Brizon starters were used. The aircraft was completed in May 1917 and its first flight was in early .January 1918. Various payloads were tested including 800, 1.000, and 1.235 kg. Flight tests with one engine shut down revealed that lhe aircraft flew very well while carrying a 711 kg payload. In early 1918 the T.5 was dismantled and sent to Saint Raphael for evaluation by the Aviation Maritime. Here it was test flown beginning 3 March 1918. It was capable of carrying a 1,500 kg payload. Advantages of the twin-engine design included stable flight on only a single engine, asymmetry being virtually eliminated by the tandem engines. Furthermore, with the Navy's decision to end production of the Tellier T 3 and T.6, there was a surplus of Hispano-Suiza engines available. The T.5 was also a very stable gun platform in flight.
  Approximately 10 T.5s were ordered by the Aviation Maritime in May 1918. These were built at the State Arsenal at Cherbourg.


T.5 Two-Seat, Cannon-Armed Flying Boat with Two 250-hp Hispano-Suiza 8B Engines
   Span 22.96 m; length 15.88 m; wing area 86.5 sq. tn
   Empty weight 2.100 kg; loaded weight 5,300 kg
   Maximum speed: 135 km/h; endurance 4 hours 30 minutes
   Armament: a 47-mm Hotchkiss cannon and 300 kg of bombs
   Approximately ten built



Nieuport-Tellier Designs

  The Nieuport firm acquired a controlling interest in the Tellier firm in late 1918. Tellier's designs were redesignated as follows:
   Tellier T.5 - Nieuport BM (Bimoteur or twin-engine aircraft see - above).



Nieuport S

  The Nieuport S represented an amalgamation of Tellier's and Nieuport's design philosophies. It was an amphibian with the fuselage of the T.3, a wing similar to that used on the T.4, and a tail configuration similar to preceding Nieuport designs. The engine was to have been a 430-hp Darracq-Coatalen 12A or 450-hp Sunbeam, but it does not appear that this aircraft was ever built. (See entry under Tellier for illustration.)


Nieuport S with 430-hp Darracq-Coatalen 12A or 450-hp Sunbeam (all data provisional)
   Span 23.8 m; length 14.1 m; height 4.24 m; wing area 95 sq. m
   Empty weight 2,540 kg; loaded weight 3,800 kg
   Maximum speed: 140 km/h; climb to 1,000 m in 9 min. 30 sec.; climb to 2,000 m in 22 min. 30 sec.; endurance 4 hours
   It is not known if any were built