Unfortunately, the testing has been ambiguous, and while it has not refuted the claims, neither has it sustained them. Part of the problem is that the tests have not been designed to prove or disprove the ability of the channel wing aircraft to perform, but have only investigated certain aspects which were amenable to contemporary testing techniques. Another part of the problem is that Custer has understandably maintained such tight control over his patents that full development programs have not been possible.

There are additional factors which will be covered in the second part of the article, which are more difficult to define. On the one hand, government reaction to Custer through the years has ranged from mildly patronizing to outraged; it is fairly evident from the correspondence that Willard Custer's native engineering talents didn't receive the same respect that would have been accorded an established manufacturer.

On the other hand, Custer has probably been too optimistic about the potential of his invention, while soft-pedaling some of the real problem areas. His reluctance to let professional engineers tell his story in objective, conventional, engineering terms, clearly delineating both advantages and disadvantages, has undoubtedly cost him some credibility.

As we shall see, engineering opinion is still divided about the Custer Channel Wing, but that doesn't inhibit an examination of the airplanes themselves, which constitute a unique line in American aviation.

In 1937 Custer built a single engine model which demonstrated vertical lift, and by 1939 he had formed a corporation, the first of many business entities which would sustain the idea over the years. continue...