The Miles M.65 Gemini was one of Britain's most successful post-war light touring aircraft — a twin-engine, four-seat design that flew from 1945 and served operators across the world. Online Aviation Library preserves the surviving original factory documentation for this aircraft and its powerplants in a single structured collection.

What This Collection Covers

Airframe — Miles Aircraft Limited, Reading, England

• Miles M.65 1A Gemini Pilots' Notes and Flight Manual (Publication No. C.12, November 1946) — Standard operating procedures, weight and balance limits, emergency checklists. Stamped: Aer Lingus Dublin Airport Technical Library, Accession No. 2494.
• Miles M.65 Gemini Service Manual (Publication No. C.11) — Wood structure repairs, electrical landing gear actuators, engine rigging, and maintenance data.
• Miles Gemini Ambulance Version — Sales Brochure — Original factory brochure for the dedicated air ambulance configuration, featuring registration G-AISN in flight.
• Miles Gemini Specification Sheet (Ref. M65/1/9/7/2500/A) — Factory performance and configuration specification document.

Powerplant — de Havilland / Rolls-Royce Gipsy Major Series

• Gipsy Major 1 and 10 — Spare Parts List (Original publication June 1947; this copy April 1964, incorporating Amendments No. 1 to 22) — Issued by Bristol Siddeley Engines Limited, Leavesden, Hertfordshire.
• Gipsy Major Series 10 — Operation, Maintenance, and Overhaul Handbook — Issued by Rolls-Royce Limited, Small Engine Division, Leavesden. ARB Design Approval No. AD/1005/38. Certified by Chief Design Engineer R.M. Heathcote. Complies with British Civil Airworthiness Requirements, Section A, Chapter A6-2.

Aircraft Engineering Summary

The Gemini's airframe is a low-wing monoplane derived directly from the Miles Messenger, featuring thick-section spruce and plywood wing construction skinned in madapolin textile for laminar flow. Non-retractable high-lift trailing-edge flaps (Mk 1A) provide high drag and lift coefficients for short-field operations. The wide-track, electrically operated retractable tailwheel undercarriage gave excellent grass-field handling.

Standard powerplant for the Mk 1A is two 100 hp Blackburn Cirrus Minor II inverted four-cylinder engines. Higher-power variants include the Mk 3A (145 hp de Havilland Gipsy Major 10) and the M.75 Aries (155 hp Blackburn Cirrus Major III). Engine nacelles are structurally anchored via a heavy plywood main spar to dampen vibration.

Mk 1A Performance Data

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.

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