History is rife with illustrations of those rueful conditional verbs "could have," "would have" or "should have" -- and never more so than when a momentous anniversary rolls around. The latest example is the 100th anniversary this Wednesday of the huge accomplishment of the American Wright brothers, Orville and Wilbur, who on Dec. 17, 1903, ushered in the era of powered and manned flight with an erratic 12-second ride across a windblown North Carolina sand dune.

The Wright brothers worked independently, but not in a vacuum. Around the dawn of the 20th century, flight was in the air, so to speak. The Wrights' research was preceded by, or contemporaneous with, the efforts of men like Samuel K. Langley, Otto Lilienthal and Octave Chanute, although, as Wilbur said in 1912, the machines they had built "were guilty of almost everything except flying." At the time, Wilbur added, "there was no flying art in the proper sense of the word, but only a flying problem."

If the Wrights' American and European competitors came close, on occasion, to solving the problem of getting a machine to fly, a little-known genius of aerodynamics in far-distant Japan may have come closest of all, according to many aviation experts. Chuhachi Ninomiya, a self-taught inventor and samurai's son from Shikoku, built a revolutionary fixed-wing plane, dubbed Karasu, or Crow, and powered by rubber bands, which made a successful unmanned flight as early as 1891.