What do you mean, "it was not the difference between the E and F models"?
I mean exactly that, the quote in contention in Freeman's book spoke of differences
between F models not the differences between E and F models. Of course there were differences between the models. That is not in dispute.
Here is the section in full. Emphasis added by me.
"There were 27 different
B-17F blocks from Seattle, seventeen for the Douglas model and eleven with Vega during the course of production. The three plants used prefabricated sub-sections from the Boeing Wichita factory and other contractors but, despite using the same drawings and engineering data, each had its own methods of assembly and inevitably some minor differences arose between what were otherwise supposedly identical airframes."
Up to this point I have no issues with what he wrote. Remember we are talking solely about "F" models of the B-17 at this point. This next paragraph or two is where I and others take issue especially as to source documents or references.
"
Douglas built B-17's had strengthened main wing sections. Vega production had a similar wing section and reinforcement of the fuselage. AAF engineering officers claimed that in addition to being heavier and bringing a slight change in flight attitude, the Vega B-17Fs suffered from stress constrictions where two sections of the fuselage were joined at the radio room. The wings from a Douglas or Vega B-17s would not fit a Boeing-built aircraft due to the former two having been built in a higher-temperature environment."
He appears to be mixing two thoughts to me, one that Douglas and Vega wing structures were significantly different, in Vega's case causing stress issues. But then states that the only reason the wings were not interchangeable with Boeing built Fs was the temperature at which they were built.
Now all of what he said could well be correct and true. But without references, or even other anecdotal evidence to support the claim, indeed a total lack of such evidence where other authors recount wing field replacements, you have to question exactly what was and was not true in his account.
I have no doubt whatsoever that Freeman felt what he wrote was true and that he almost certainly has references in his notes to support that. But since we cannot find any of those references it leaves reasonable doubt as to the completness of the account.
