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

MORANE-SAULNIER TYPE AN (MoS 31 TO MoS 34) France

   Designed to use a 450 hp Bugatti 16-cylinder water-cooled engine, the Type AN two-seat fighter completed in the summer of 1918 was a large, two-bay equi-span staggered biplane with a monocoque fuselage. Officially tested at Villacoublay on 27 October 1918, the Type AN produced disappointing results and alternatives to the unorthodox Bugatti engine were investigated. The 400 hp Liberty 12 was installed in the Type ANL and the 450 hp Renault 12Kb in the Type ANR, both being tested in 1919. The armament of the AN series aircraft consisted of a forward-firing 7,7-mm Vickers gun and twin 7,7-mm Lewis guns on a flexible mount in the rear cockpit. The final variant of the basic design, the Type ANS, was fitted with a 530 hp Salmson 18Z 18-cylinder water-cooled two-row radial. Development continued through 1919, the Type ANL becoming the MoS 32, the ANR becoming the MoS 33 and the ANS becoming the MoS 34, but, although some promising results were obtained, further development was discontinued. The following data relate to the Bugatti-engined prototype.

Max speed, 140 mph (225 km/h) at sea level.
Time to 6,560 ft (2 000 m), 6.66 min.
Loaded weight, 3,902 lb (1 770 kg).
Span, 38 ft 5 4/5 in (11,73 m).
Length, 27 ft 4 1/2 in (8,34 m).
Height, 9 ft 1 in (2,77m).
Wing area, 441.33 sq ft (41,00 m2).

Jane's All The World Aircraft 1919

THE MORANE SAULNIER. TYPE C.2.
  
  
Type of machine Two-seater Tractor Biplane.
Name or type No. of machine Morane Saulnier. Type C.2.
Span 11.726 m.
Gap 1.7 m.
Overall length 8.345 m.
Chord 1.9 m.
Total surface of wings 41 sq. m.
Span of tail 3.66 m.
Engine type and h.p. 420 h.p. Bugatti.
Airscrew, diameter 3.1m.

C.Owers French Warplanes of WWI. Volume 1: Fighters (A Centennial Perspective on Great War Airplanes 43)

The Morane-Saulnier AN (MoS.31.C 2 to Mos 34.C 2)
  
  Ettore Bugatti designed a sixteen-cylinder aero engine of 400-hp around mid-1917. The engine was basically two 200-hp engines mounted side by side. Two crankshafts were geared to a central hollow airscrew shaft through a reduction gear. The engine had made its first run on 23 October 1917, and great things were planned for it. It was to be mass produced in France by Peugeot. In a S.T.Ae. report of January 1918, it was stated that the frame of the body of the Morane C2 Bug. 16 (420) was ready and the fuselage construction had begun. This Morane C2 was a reference to a new Morane-Saulnier type to be powered by the Bugatti engine. When Robert Morane became aware of the new engine is unknown, but Morane-Saulnier had a number of experimental aircraft under design or construction in November 1917. One of these was an all-monocoque single-seat fighter powered by the 450-hp Bugatti and incorporating a jettisonable fuel tank. By January the design had become a two-seat fighter.
  The US Army notes on the machine state that it was designed primarily as a cellue for the Bugatti 16 cylinder motor.
  Refinement in design is carried to an extreme very rare attained hereto in French machines. It was thought that the Bugatti motor would offer an excellent power plant for a fighting plane, that is great power combined with a minimum of head resistance.
  The fuselage was designed especially with the view of cutting down resistance, and is in many respects a great advance over anything which has been produced up to the present time. It is deep and roomy and gives excellent protection to both pilot and gunner. The construction of the empennage is especially noteworthy as a sample of what may be done in the way of integral construction and streamlining. The liaison between the pilot and gunner is excellent and the visibility for both, especially upward and forward is excellent.
  The performance actually obtained with this machine so far has been somewhat disappointing due to trouble with the motor, which has not developed the power expected of it. When fitted with a more reliable high powered motor, this machine should prove to be very interesting.
  It is doubtful if this machine could be used for landing and getting off from rough ground because of the fact that is sets so close to the ground and its wing tips are not provided with skids. On smooth ground, however, this machine lands at a comparatively slow speed.
  The report concluded by stating that the machine passed its static test with a factor of safety of 9. The Bugatti engine was selected for construction in the USA and it was apparently the interest in the engine that prompted this report. The Bugatti was to be flown in the Le Pere LUSAC 213 and LUSAGH-21 in the US. It was not a success and only 11 of the 2,000 ordered had been delivered by the Armistice.
  The first Morane-Saulnier AN (serial No. 1898) that emerged in the summer of 1918 was a two-bay biplane. The fuselage was of three-plywood monocoque construction. The bottom of the fuselage followed the contour of the bottom of the lower wing, with the sides nearly flat and slightly tapered in at the bottom.
  To the rear of the gunner's cockpit the fuselage assumed a circular section that was maintained for the remainder of its length. Both the horizontal tailplane and the fin were built integral with the monocoque construction. In general, the fuselage was symmetrical about the longitudinal axis. The wings had pronounced sweepback. The upper wing was built in two halves meeting on the centre-line. Balanced ailerons were fitted to both the upper and lower wings and connected by rods. There were two pairs of interplane struts outside the fuselage on each side.
  The horizontal fixed tailplane and fin were of monocoque construction fairing into the rear end of the streamlining of the fuselage. A balanced rudder of approximate trapezoidal shape was fitted. The elevators were also balanced. All controls were carried within the fuselage and the control surfaces were actuated by torsion tubes. The landing gear, comprised two pairs of V-struts and rigid M-bracing to the axle, supported two 750 x 125 mm wheels. The tail skid was provided with a streamline housing.
  The elegant lines of this construction were spoiled by the ugly installation of the Bugatti engine. Twin radiators were installed on the leading edge of the upper wing and a massive central exhaust pipe was required by the 16 cylinders. The spinner had a large central opening for the armament included a 37-mm cannon firing through the airscrew shaft, the engines arrangement of eight upright cylinders on each side of the central shaft allowing for such an installation. The pilot also had a synchronised Vickers gun mounted to the starboard side of the cockpit. The radiators were later replaced by Lamblin "lobster pot" radiators attached to the nose.
  The pilot had an uninterrupted upward view by means of a central cut-out in the rear of the upper wing. The gunner had dual controls for an emergency.
  A French report on engines in late November 1918, noted that the mounting study of the Morane 31 with 450-hp Renault 12 was complete, and with the Liberty engine was proceeding. Given the experimental nature of the Bugatti engine this was a sensible decision. It appears that three engines were considered for the Type AN - the 450-hp Renault 12Kb; the 400-hp Liberty 12; and the 370-hp Lorraine-Dietrich 12 Da.
  Official tests of the Bugatti powered machine took place on 27 October 1918. As noted above the results were disappointing. The aircraft was returned to its makers for modification to the exhaust manifold. It was tested again in late November. It appears that the Bugatti powered AN had been selected for production despite its climbing performance being less than that of the S.E.A. 4C. It was given the official S.T.Ae. designation MoS.31.C 2.
  The Liberty powered AN was designated ANL and the Renault powered example, the ANR. The last version was the ANS with the 530-hp Salmson eighteen-cylinder twin row radial water-cooled engine. However, although Morane-Saulnier designated these the MoS.32, Mos.33 and MoS.34 respectively, official files designated all versions as the Mos.31.C 2 no matter what engine was installed.
  The Type ANL had a blunt nose, Lamblin radiators attached to the lower nose, extremely long exhaust pipes attached to the fuselage and a revised upper wing that now incorporated a centre-section. This required a complex arrangement of centresection struts. The ANL was tested at Villacoublay in 1919. Another version with thick wings was also tested in May. The similar appearing Type ANR also appeared in 1919. The engine installation was slightly neater. As noted above the final version was the ANS. The big, bulky engine gave the machine an even more ugly look than the Bugatti engine version. This was the last version of the AN to fly.
  Description of the Morane-Saulnier ANL 81 ANR from the MoS XXXII C 2/XXXIII C 2 manual.

The ANL

  The fuselage was constructed in two parts. The forward part was in metal (in tube, angle iron and dialuminium U-sections). The engine and pilot's cockpit were supported in this section. The engine section was covered by aluminium panels with inspection doors for access to the engine and all other components. This section was supported by the landing gear frame when erecting the lower wings. It connected to the rear section at the rear gunner's position. (See Pl. II).
  The rear section was constructed in wood around eight braced ash beams with plywood annular hangars, and wrapped in a plywood shell that was formed in two halves on a mould. The rear section had a circular cross-section except where it connected with the lower wings. It carried the rear gunner's cockpit with a type T.O.-7 bis gun ring. Boxes that could accommodate Lewis gun drums were attached to the sides of the fuselage and on the floor.
  The tail surfaces as well as the tail skid arrangement were carried by this section. The fin was built integral with the fuselage. (See Pl. III).
  The two-bay wings were swept back 10° and had a stagger of 466 mm. The lower wings connected to the metal section of the fuselage. All wings were cut back at the root to allow for improved sight distance for the crew. The struts were constructed of duralumin tube and were adjustable on one end. (See Pl. V).
  The balanced ailerons were mounted on ball bearings. The lower ailerons were controlled by torsion tubes from the control stick. They were connected to the upper ailerons by adjustable connecting rods.
  The cabane was formed by six tubes, four to the spar and two across the cabin longitudinally. These supports are crosswise braced by 40/10 piano wire. (See Pl. VI).
  In addition, on each side of the fuselage, at the front and at the rear, a round tube strut and a stay connect the upper wing to the metal part of the front section of the fuselage. The tubes were streamlined with wooden fairings.
  The front edge of the centre-section was formed by the water tank with the gravity fuel tank behind. (See Pl. VI).
  The rudder and elevators were balanced and of metal construction. The rudder was mounted entirely above the fuselage. (See Pl. IX).
  The connections of the control surfaces were carried inside the fuselage.
  The lower vertical fin was molded with fuselage and provides the fairing for the tail skid.
  The horizontal stabilizer is guyed by eight profiled wires attaching it to the bottom of the lower fin and to the top of the upper fin. (See Pl. IX). Access to the control organs was provided by three access panels in the fuselage.
  The landing chassis comprised two lateral Vees of torpedo tube and duralumin, and a duralumin Vee on the spreader bar. Two articulated half-axles were held in place by rubber shock cord wrapped around two brackets fixed to the lateral Vees. The wheels were "Palmer" 55 bore type (750 x 125). (See Pl. VII).
  The tailskid was made of reinforced wood with a sheet metal shoe with braking notches. The skid was guided by a slide inside the fuselage, its axis of articulation maintained by two struts on its outside. (See Pl. VIII)
  The aircraft had a main station and a secondary station for the machine gunner's use. (See Pl. IX).
  Dual control was fitted however the dual steering system did not have a clutch. The pilot had the usual rudder bar on a cone shaped support on the metal floor. The distance from the rudder bar to the pilot's seat was adjustable (maximum distance 45 mm). The gunner had two independent pedals to control the rudder.
  The Liberty engine was mounted on two U-shaped duralumin engine bearers attached to the front metal cradle. This arrangement allowed for easy change of the engine. (See Pl. III).
  The aircraft had a capacity of fuel and oil that allowed an endurance of three hours. The main fuel tank of 235 litres capacity was under the floor. This was filled from the pilot's position by means of a collar such that the mouth was at the upper level of the fuselage. Filling was ensured by means of an "auto-gauge" placed on the tank that was visible through a window placed in the floor of the cockpit. The gravity tank in the centre-section contained 11 litres. (See Pl. X).
  From the main tank, the fuel was sucked up by the pump (Margue "A.M.") then was discharged into a distribution box with two taps, from where it could be sent to the carburetors, or to the charge nipple. The carburetors receive the highest pressure. (See Pl. X).
  A hand turbine pump ("Weymann" brand) was provided to replace the "AM" pump if the latter stopped. The crank of the Weyman pump was required to be turned from time to time to fill the tank.
  A pipe was connected to the pump discharge and connected to a pressure control manometer placed on the pilot's dashboard. The pipes were aluminum or, failing that, copper.
  Oil was contained in a 30 litre tank positioned in front of the pilot and behind the engine. (See Pl. XI). The oil left the tank under load and arrived at the engine pump. At the outlet, the oil was discharged to the oil tank, passing through a radiator placed on the left side of the fuselage.
  Water was contained in the gravity charge tank, in the engine and the pipes. (See Pl. XII).
  The Radiators were of the "Lamblin" (Petit-Vicart-Cousin) type; they were fixed on each side of the fuselage, below the engine level, by faired round tubes. They were fitted with shutters, that the pilot controlled, allowing the temperature of the water to be adjusted. The water coming out of the engine went down to the radiators. From there a turbine pump forming part of the motor sent it to the gravity tank in the leading edge of the centre-section and the motor. These pipes were made of aluminum and tinned steel. (See Pl. XII).
  The exhaust pipes (one per group of cylinders) had a circular cross-section and lay on each side of the fuselage without touching it. In addition, an asbestos lining preserved the fuselage.
  Start-up was provided by the "Brizon" system (acetylene below and starting magneto).

Pilot's cockpit. (See Pl. XIII).

  An "efficient windshield" was placed in front of the pilot.
  The pilot had at his disposal a fixed Vickers machine gun, controlled by the engine, placed to his right and above the cowling. The cartridge case could hold 500 cartridges. The links and spent cartridges were collected. The trigger was placed on the control column.
  To the right of the pilot was the crank of the "Wayman" turbine and the control for the radiator shutters.
  To the pilot's left were:
  - The engine control handles (double).
  - The compass on the floor.
  Before him was the instrument panel on which were mounted:
  - A tachometer;
  - Two "Chenu" type thermometers (water);
  - Two pressure gauges (petrol and oil);
  - An altimeter and finally the special contact to the "Liberty" engine.
  The taps of the petrol distribution box also lead to this panel which carried explanatory plates
  There was provision in the rear gunner's cockpit for the location and mounting of a camera with f=50.
  Provision was also made for the location of a "Badin" speed indicator and a double oxygen system for high altitudes.
  A 600-watt generator with voltage regulator was placed in the fuselage, and was activated by the motor. The circuit about it was to the right of the gunner. The tables in each cockpit each carried a rheostat and an outlet.
  If following any accident, it was feared that the machine has been knocked out of alignment, it was to be checked that the dimensions indicated had not varied by more than 5 mm. If this was the case, no part was damaged, and the aircraft could be reused without sending it to a repair workshop.

MoS ANR Type XXXIII C 2

  The main difference is the replacement of the Liberty motor with a Renault type 12 KB motor.
  For this some changes are necessary in the following parts:
   1. Engine Mounting: This is done in a similar way by means of metal engine supports bracing
   2. The Cabane: The metallic connection plane, of similar construction, has a wider width of (1.300 cm) because of the larger size of the Renault engine, and to allow the shrouding of the cabin (modified like Pl. III).
   3. Upper wings. The upper wings were shortened by the amount that the cabin plan had been enlarged in order to maintain the same wingspan of the aircraft (Total projected length of the upper wings = 5 m 213).
  The 270 litre main tank was mounted as in the "Liberty" AN under the pilot's floor, between the lower wing attachments. The gravity tank of 17 litres was in the upper wing centre-section. An additional 90 litre tank was mounted in the fuselage at the rear of the turret. It was piped to the main tank via a tap-controlled valve at the pilot's cockpit. With the tap open, the flow of petrol from the additional tank to the main tank was automatic. Apart from this, the circulation of fuel was identical to that of the "Liberty" motor version (Weymann pump, A.M. pump, etc.) (See Pl. XV).
  The levers for air, gas, corrector, were placed to the left of the pilot.
  The contact and control lever of the machine gun were placed on the joystick.
  The exhaust manifold was directed laterally to the front.
  Starting was provided by the Brizon system (Acetylene and starting magneto).
  The cowling of the front fuselage retained its general shape, but was adapted to the new mounting of the engine, up to the pilot's cockpit.
  The generator control, although analogous, could be disengaged by means of a special device supported by the housing of the machine gun synchronization system.
  As a result of the modification of the main tank (270 liters instead of 235), the control rod for the connecting rods is deferred to the rear of the attachment of the rear spars of the lower wings, which has the effect of lengthening:
  1. The horizontal steering tube;
  2. The rods themselves.

  All other parts of the aircraft, cell masts and guy lines (except in the central part), the lower wings, the control surfaces, the wooden fuselage section, the metal rear part of the fuselage (Nacelle), the elastic pad shock absorber, the undercarriage, and general fittings, were the same as those for those of the Liberty engine type.
  The circulation of oil and the circulation of water, remained absolutely analogous and were only slightly modified at the pipe connections with the engine.
  The setting was identical to that of the Liberty engine type for the control surfaces, the machine gun, etc. It is also the same for the cell, except for the offset of the planes which is 525 mm instead of 466 (which corresponds to advancing the upper plane of 59 mm leaving it to advance the higher plane of 59 mm leaving it at the same distance from the fuselage.)
  To perform the operation of setting the incidence of 2.6% of the fuselage, the vertical distance rating from the nose of the propeller to the tail tip, which is 297 mm for the Liberty engine, becoming 264 mm for the Renault motor device which is slightly longer. Likewise, the symmetry dimension I = 6m.800 becomes slightly larger. (Pl. XIV).
  For all the other operations to be carried out to adjust the airframe, the instruction was to follow those for the Liberty engine version.
  The English magazine Flight reported on the AN displayed at the Paris Aero Show in 1919:

  This machine has a monocoque body, with wing roots built integral as in some German machines. The pilot sits just behind the top centre section, and is armed with two synchronised machine guns. The gunner’s cockpit is immediately behind that of the pilot, and has a gun-ring for two machine guns. There is further a small gun tunnel in the floor of the fuselage, through which the rear gunner is able to fire in a downward and rearward direction. The engine of this machine was a Liberty 400 h.p., the only one at the show.
  The following designations were apparently applied to the various versions of the type AN in 1919 as follows:
   ANL - Mos XXXII
   ANR - MoS.XXXIII
   ANS - MoS.XXXIV

  The Morane-Saulnier exhibit at the VIe Salon Aeronautique held in Paris in December 1919. The Aeroplane issue of 7 January 1920, reported that Aeroplanes Morane-Saulnier, Rue Volta, 3, Puteaux, exhibited four machines - three parasol monoplanes and an "unwinged biplane." This latter was an ANL fuselage. The report noted that the observer had a third Lewis gun mounted in a tunnel firing down and aft.
  There was no call for the machine in the post-war climate although Morane-Saulnier did try to sell it to foreign governments, Temple N Joyce exhibiting one in the USA (See Chapter 4).


Morane-Saulnier AN Specifications
Source & Type 1 Bugatti 420-hp 2. Type ANL MoS XXXII C2 2. Type ANR XXXIII C2 3. Type XXXIV 4. ANL/ANR
Span, m 11.726 11.726 11.716 11.72 11.725
Length, m 8.345 8.350 8.590 8.12 8.350
Height, m - 2.730 2.730 2.73 -
Chord, m 1.90 - - 1.9 -
Gap, m 1.70 - - 1.70 -
Stagger, m 0.54 - - 0.466 -
Dihedral Nil - - - -
Incidence - - - 2.6% -
Tread, m - 2.100 2.100 2.1 -
Tyres, m 750x125 - - - -
Wing Area, m2 41.0 41.500 41.500 41.50 -
Aileron Area, m2 - 3.460 3.460 3.46 -
Tailplane Area, m2 - 2.100 2.100 2.1 -
Elevator Area, m2 - - - 2.1 -
Fin Area, m2 - - - 0.8 -
Rudder Area, m2 - - - 0.72 -
Fuel main, L 280 - - - -
Fuel nourrice, L 20 - - - -
Oil, L 35 - - - -
Useful load, kg 320 - - 320.5 566-698
Crew, kg - 160 - 150 -
Instruments, kg - 10 - 10 -
Armament front, kg - 125 - 24 -
Armament back, kg - - - 15.5 -
Armament lower, kg - - - 17 -
Electrical equipment, kg - - - 25 -
Photographic equipment, kg - - - 20 -
Combustible load, kg 246 219 - 285 -
Oil, kg - 27 - 92 -
Empty, kg 1,310 - 1,260 1,300 -
Total, kg 1,876 1,776 - - -
Climb to
   1,000 m 2 min 34 - - - -
   2,000 m 6 min 07 5 min 45 8 min 15 - -
   3,000 m 10 min 22 - - - -
   4,000 m - - 23 min 50 - -
   5,000 m - 26 min - - -
Speed in km/hr
   Minimum - - - - 130
   Maximum 225 - - - 200-210
   at 2,000 m - 210 203 - -
   at 4,000 m - - 192 - -
   at 5,000 m - 195 - - -
Ceiling in m - - - - 6,500
Endurance - 3 hrs - - 3 hrs
Engine Bugatti Liberty 400 Renault 12 KB Salmson Liberty 400-hp/Renault 450-hp

Source.
1) McCook Field Technical Section. Typed sheet "Morane-Saulnier 31-C2 (Bugatti)". NASM File AM-800057-001.
2) Notice Technique sur les Biplans Type Mo.S XXXII et XXXIII C2. Morane-Saulnier booklet on the types.
3) "Characteristics of Morane Type XXXIV Airplane." Report dated 7 October 1920. NASM File No.AM-800065-01.
4) "Paris Salon", The Aeroplane, 7 January 1920, P.24.