Morane-Saulnier Type P (MoS.21) — Primary-Source Technical Archive

The Morane-Saulnier Type P — military designation MoS.21 — was France’s definitive two-seat parasol reconnaissance monoplane of the First World War. Introduced in 1916 as a thoroughgoing aerodynamic refinement of the earlier Type L and LA, it served the Armée de l’Air, the Royal Flying Corps, and the Italian Corpo Aeronautico Militare in artillery spotting and tactical reconnaissance roles, with 565 production units completed.

This Living Collection assembles five primary-source documents spanning three languages and two nations — the original Morane-Saulnier factory spare parts croquis, the French and Italian-language Le Rhône engine assembly and adjustment manuals, the British Gnome & Le Rhône Engine Co. care manual, and the rare Italian FIMAG rotary engine starter apparatus guide — forming the most comprehensive multi-lingual technical reference available for the Type P and its Le Rhône 9J powerplant.

Every document is an archival, static-copy edition fixed at its original publication date — primary-source material for historians, restorers, flight simulation specialists, and serious collectors.

Document Manifest

1. Croquis des Pièces de Rechange — Appareil P 110-120 HP Rhône, Type S.F.A. N°s XXI et XXVI — Factory Spare Parts Illustrated Croquis. Issued by Aéroplanes Morane-Saulnier, 206 Boulevard Pereire, Paris. Covers airframe components for the Type P parasol monoplane across S.F.A. variants XXI and XXVI: wing strut assemblies, fuel and oil reservoirs, upper pylon/cabane structure, elevator and control linkages, pilot’s cockpit components, and Le Rhône engine accessories. Language: French.
2. Instructions sur le Montage et le Réglage des Moteurs “Le Rhône” — Type C, 80 HP · Type J, 110 HP — Engine Assembly & Adjustment Manual. Issued by Société des Moteurs Gnome & Rhône, Anonyme au Capital de 1.475.000 Francs, Siège Social & Bureaux: Paris — 3, Rue La Boétie, 3 — Paris (VIII°). Includes “Recommandations importantes pour la bonne marche du moteur”: cylinder bearing lubrication and valve lapping procedures. Language: French.
3. Apparecchio per l’Avviamento dei Motori Rotativi d’Aviazione — Tipo “Le Rhône” da 110 e 130 HP — Rotary Engine Starter Apparatus Manual. Brevetti Guelpa. Issued by FIMAG (Fabbrica Italiana Motori e Accessori per l’Aviazione Guelpa), Corso Dante 41, Torino. Tipo-Litografia Eugenio Toffaloni, Torino, 1918. Covers the Guelpa-patent inertia starter system for Le Rhône 110 and 130 HP rotary engines. Language: Italian.
4. The Care of the 110 h.p. Le Rhone Engine — 9-Cylinder, Type J — British Operator’s Care Manual. Issued by The Gnome & Le Rhone Engine Co., London Office: 47 Victoria Street, S.W. Works: Blackhorse Lane, Walthamstow and The Hyde, Edgware Road, Hendon. Includes the iconic frontal photograph of the 110 HP Le Rhône 9J rotary (Fig. 1). Language: English.
5. Istruzioni per il Montaggio e Regolazione del Motore “Le Rhône” — Tipo C, 80 HP · Tipo J, 110 HP — Italian-Language Engine Assembly & Adjustment Manual. Issued by Società Italiana Motori Gnome e Rhône, Torino — Strada Venaria, 73 (Madonna di Campagna). Vincenzo Bona, Tipografo della Real Casa, Torino, 1917. Language: Italian.

Aerodynamic & Design Refinements

• Fuselage: Fully faired circular cross-section — a major drag reduction over the slab-sided Type L.
• Wing Configuration: Rigid braced parasol monoplane mounted above the fuselage — unobstructed downward and lateral visibility for pilot and observer.
• Control Surfaces: Standard ailerons replacing the Type L’s primitive wing-warping — significantly improved lateral stability and roll predictability.
• Tail Assembly: Unbraced, balanced all-moving elevator with small vertical fin — highly pitch-sensitive, no fixed horizontal stabiliser.

Engine Technical Notes

• Powerplant: Le Rhône 9Jb (or 9J) — 9-cylinder, air-cooled rotary.
• Power Output: 110 hp (82 kW) at nominal operational revolutions.
• Propulsion: Fixed-pitch, two-bladed wooden tractor airscrew.
• Lubrication: Total-loss castor oil mixed directly into the fuel stream — characteristic of all rotary engines of the period.

Handling & Stability

• Pitch: Highly sensitive — all-moving elevator with no fixed stabiliser required continuous pilot input.
• Roll: Crisp and predictable with ailerons vs. wing-warping predecessors.
• Visibility: Excellent downward and lateral; blind spot directly above and ahead during steep climbs.

Performance Data

Armament & Engineering Bulletins

• Forward Armament: One 7.7 mm (0.303 in) Vickers machine gun, synchronised via Alkan-Hamy gear to fire through the propeller arc.
• Rear Armament: Flexible ring-mount for one or two Lewis guns in the rear cockpit for observer/gunner defensive use.
• Secondary Payloads: Structural provisions for light tactical reconnaissance bombs under the fuselage box-girder.
• Production: 565 units built across S.F.A. variants XXI and XXVI.

This is an archival, static-copy edition fixed at its original publication date. Intended for historical reference, flight simulation, museum restoration, and educational use only. Not approved for active airworthiness maintenance under FAA 14 CFR § 43.13, EASA Part-M, or equivalent international regulations. Operators of active aircraft must use current, revision-controlled publications from the Type Certificate holder or an authorized distributor.

⚠️ Regulatory Notice: Under FAA 14 CFR § 43.13 and EASA Part-M, any mechanic performing maintenance on an active aircraft must use current, manufacturer-approved revision-controlled data. This archival document does not satisfy that requirement.

Living Collections with Free Lifetime Updates — Please review our Disclaimer and Export Notice before purchasing.