Mitsubishi Ki-21 “Sally” / “Gwen” Manual Collection

A two-item historical reference collection covering the Mitsubishi Ki-21, officially designated the Army Type 97 Heavy Bomber and known by the Allied reporting names “Sally” and “Gwen”. It brings together Japanese operating documentation and an English-language photographic archive.

Collection contents

• Ki-21-II Type 97 Heavy Bomber Operating Instructions Manual (Japanese language), 九七式重爆撃機 二型 取扱説明書.
• Ki-21 Photographic Collection (English language), containing slides, photographs and brochure material.

Historical and technical scope

The reference material discusses the aircraft’s all-metal cantilever mid-wing layout, control surfaces, aerodynamic development, engine and propeller installations, handling and stability changes, performance data, defensive modifications, armour, bullet-resistant glazing and self-sealing fuel protection. It follows the evolution from the Ki-21-I with Nakajima Ha-5-Kai engines to the Ki-21-II series with Mitsubishi Ha-101 engines, including the later dorsal-turret configuration associated with the “Gwen” designation.

The Ki-21 was Japan’s principal heavy bomber during the late 1930s and the early years of the Second World War. Its surviving documentation offers a useful window into Japanese bomber design, operation and wartime modification practice.

Important: This is historical and reference material. It is not current approved airworthiness data, maintenance approval or operational guidance. Please assess provenance, rights and distribution status before use.