This is the best film of its genre ever made. Howard did an amazing job as actor, director and producer. His death (shot down on June 1943 in a commercial DC3 over the Bay of Biscay by German fighters outside of their patrol zone) took place just over eight months after the film's release and while still playing in theaters. It is gratifying that he saw its success and its impact on morale. It is a terrible tragedy that the career of this brilliant actor and director was cut short, as he could have easily continued to make a tremendous contribution well into the 1970's.
As for RJ MItchell, his five year fight with cancer was equally tragic, although he was able to view many test flights, and even earned his pilot's license in 1934, a year after a colostomy. He passed away three years and a month before the start of the Battle of Britain.