Morane-Saulnier Type AI (MoS.27/29/30) — Primary-Source Technical Archive

The Morane-Saulnier Type AI represents the pinnacle of French WWI parasol-wing monoplane engineering. Developed in early 1917 by Robert and Léon Morane alongside Raymond Saulnier as an advanced monoplane alternative to the SPAD VII and Nieuport 17, the Type AI delivered exceptional agility and a revolutionary total-vision parasol configuration — only to be grounded from frontline combat after three months following a series of fatal wing structural failures under high-G loads. Redesignated as the MoS.30 advanced trainer with a derated Le Rhône 9J, it went on to serve as one of the premier aerobatic trainers for both the French Aviation Militaire and the United States Air Service in France.

This Living Collection assembles the two original factory Dossiers Techniques — the first edition covering S.F.A. XXVII & XXIX (Gnome Monosoupape 160 hp) and the combined edition adding S.F.A. XXX (Rhône 120 hp) — together with four primary-source Le Rhône engine manuals spanning three languages and two nations: the French Gnome & Rhône assembly manual, the Italian FIMAG rotary starter apparatus guide (Brevetti Guelpa, 1918), the British Gnome & Le Rhone Engine Co. care manual, and the Italian Società Italiana Motori Gnome e Rhône assembly manual (Vincenzo Bona, 1917).

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. Avion Morane-Saulnier Type “A.I.” — Dossier Technique de l’Avion (Combined Edition) — Types S.F.A. N°s XXVII et XXIX à Moteur “Monosoupape Gnôme, 160 chevaux” · Type S.F.A. XXX à Moteur “Rhône, 120 HP”. Description, Notice de Montage, de Réglage, et d’Entretien, Notice de Manœuvre. Aéroplanes Morane-Saulnier, 206 Boulevard Pereire, Paris. Cream cover. Language: French.
2. Avion Morane-Saulnier Type “A.I.” — Dossier Technique de l’Avion (First Edition) — Types S.F.A. N°s XXVII et XXIX à Moteur “Monosoupape Gnôme, 160 chevaux”. Description, Notice de Montage, de Réglage, et d’Entretien, Notice de Manœuvre. Aéroplanes Morane-Saulnier, 206 Boulevard Pereire, Paris. Grey-blue cover. Language: French.
3. Instructions sur le Montage et le Réglage des Moteurs “Le Rhône” — Type C, 80 HP · Type J, 110 HP — Engine Assembly & Adjustment Manual. Société des Moteurs Gnome & Rhône, Paris — 3, Rue La Boétie, 3 (VIII°). Includes “Recommandations importantes pour la bonne marche du moteur”. Language: French.
4. Apparecchio per l’Avviamento dei Motori Rotativi d’Aviazione — Tipo “Le Rhône” da 110 e 130 HP — Rotary Engine Starter Apparatus Manual. Brevetti Guelpa. FIMAG, Corso Dante 41, Torino. Tipo-Litografia Eugenio Toffaloni, Torino, 1918. Language: Italian.
5. The Care of the 110 h.p. Le Rhone Engine — 9-Cylinder, Type J — British Operator’s Care Manual. The Gnome & Le Rhone Engine Co., London Office: 47 Victoria Street, S.W. Works: Blackhorse Lane, Walthamstow and The Hyde, Edgware Road, Hendon. Includes Fig. 1: frontal photograph of the 110 HP Le Rhône 9J rotary. Language: English.
6. Istruzioni per il Montaggio e Regolazione del Motore “Le Rhône” — Tipo C, 80 HP · Tipo J, 110 HP — Italian-Language Engine Assembly & Adjustment Manual. 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 Notes

• Configuration: Parasol monoplane — wing elevated above fuselage for total upward and forward visibility.
• Wing: Rigid constant-chord with slight sweepback; chord-wise duralumin and steel strut trussing replacing tension wires.
• Fuselage: Streamlined circular cross-section — curved wooden formers and longitudinal stringers for minimal drag.
• Cowling: Tightly cowled open-front circular nose with seven fretted ventilation cut-outs for rotary engine cooling.
• Controls: Horn-balanced rigid ailerons — exceptional roll rate and axial roll precision.

Engine Technical Notes

• Standard Powerplant: Gnome Monosoupape 9N — 9-cylinder air-cooled rotary, 150–160 hp.
• Alternative: Le Rhône 9R (180 hp) on later production models.
• MoS.30 Trainer: Le Rhône 9J (110–120 hp) — derated for structural safety and advanced aerobatic training.

Handling & Stability

• Roll: Exceptionally rapid roll rate via horn-balanced ailerons — highly axial.
• Pitch: Extremely sensitive — small tailplane and balanced elevators required constant pilot concentration.
• Gyroscopic Precession: Powerful rotary torque demanded significant rudder coordination in tight turns.
• Structural Grounding: Fatal mid-air wing collapses under high-G loads led to frontline withdrawal after three months of service (late 1917).

Performance Data

Variant Designations & Armament

• MoS.27 (Type AI C1): Single-seat fighter — one synchronized 7.7 mm Vickers machine gun.
• MoS.29 (Type AI C1): Dual-gun combat variant — twin synchronized Vickers machine guns over the engine cowling.
• MoS.30 (Type AI E1): Advanced aerobatic trainer — Le Rhône 9J (120 hp), reinforced wing junctions, used by French Aviation Militaire and US Air Service in France.

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.

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