The Dinah went to war before the war officially began. In October 1941 — documented flights on the 20th and 22nd — Ki-46s made clandestine high-altitude reconnaissance runs over British Malaya, photographing airfields, ports and defences ahead of Japan’s planned December offensive. Flying high and fast, they were effectively immune to the fighters of the day, and they handed Japanese planners a detailed picture of the ground they were about to invade. It was exactly the mission the aircraft had been designed for: see everything, and leave before anyone can respond.

Where many contemporaries bolted engines onto a fuselage, Mitsubishi treated the whole shape as one problem. The nacelles were faired so closely to the wing and the fuselage narrowed so smoothly behind the cockpit that the aircraft looked, in the words of more than one historian, like a piece of sculpture. That refinement was not vanity: reducing drag was what let two mid-power radials carry a two-man crew, cameras and a very large fuel load fast enough and high enough to be nearly uncatchable. The Dinah is routinely ranked among the most beautiful — and most aerodynamically honest — aircraft of the war.

As American B-29s began raiding Japan, the Army rebuilt some Ki-46-IIIs into the Ki-46-III-KAI air-defence fighter. It carried two forward-firing 20 mm cannon in the nose and a single 37 mm cannon mounted obliquely to fire upward into a bomber from below — the same idea as the German night-fighters’ Schräge Musik. In practice it was a poor interceptor: it could not climb fast enough to reach B-29 altitude in time, had no radar, no armour and no self-sealing tanks, and its light airframe was never built to absorb the recoil of a 37 mm gun. Results were correspondingly limited.

There is no credible unit cost or cost-per-flight-hour figure for the Ki-46 in the public record. It was a wartime Imperial Japanese Army procurement, and those costs were never published in a form that survives in verifiable Western references. Production totals themselves are debated — commonly given as around 1,742 aircraft, with some sources running higher — so any precise price attached to the Dinah should be treated as guesswork rather than a sourced number.