It isn't irrelevant in the context; by saying that they are only in range under 'perfect conditions' he makes it sound like the operation was barely doable. Th

It isn't irrelevant in the context; by saying that they are only in range under 'perfect conditions' he makes it sound like the operation was barely doable. This is misleading. Air operations in WWII where continuously dependent on weather conditions and the wind conditions make a large difference to the payload a piston powered aircraft of that era can carry. The B-29 was specifically designed to accomplish the strategic bombing mission in a pacific war; it would not have been accepted into production if it could not reach Japan from the Marianas Islands. In fact, it could comfortably reach the vast majority of Japan and its industrial centers, only the north of japan was outside of its normal range. The removal of most self-defense weaponry (except the tail cannon) made the entirety of Japan reachable; they simply weren't needed for night operations and Japan's fighter force was negligible by the end of the war. In fact, future b-29's were built with only a tail cannon in the first place.