The Nakajima Ki-49 Donryu ('Swallowing Dragon'), codenamed 'Helen' by the Allies, was a twin-engined Japanese bomber designed to undertake daylight attacks without the protection of escort fighters. Consequently, while it was officially known as the Army Type 100 Heavy Bomber, Its defensive armament and armour were so weighty that they restricted the Ki-49 to payloads comparable to those of smaller medium bombers. Built as a replacement for the Mitsubishi Ki-21 'Sally' heavy bomber, the Ki-49 was not a very successful design primarily because of its unreliable Nakajima radial engines. Indeed, although the Donryu saw extensive action in the Pacific War, the results achieved by units equipped with the aircraft were little short of disastrous. In this book, specialist Japanese aircraft historian George Eleftheriou provides a full account of the Ki-49's operational service over northern Australia, New Guinea, Burma and the Philippines, drawing on both primary and secondary sources never previously examined in English-language volumes on the 'Helen'. Osprey Combat Aircraft Series, Comprehensive histories of fighting aircraft and their crews, highlighting their vital role in the development of warfare in the 20th and 21st centuries, A unique source, of information, researched by recognised experts and brought to life by first-hand accounts from the combat veterans themselves, Concise, authoritative text is supported by up to 30 original colour artworks, and the best archival photography from around the world.