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In RAF Flying Review 6/60, there was a letter to the editor, mentioning 2 variants of
the unsuccesful YB-40 escorts, with an armament different to th one I knew before.
According to the description the attched profiles were shown. One version is said to
have had twin gun Emerson turrets in nose and tail, the othe 4 gun turrets, which in
the drawing appears to be british origin. Additionally in this aircraft the dorsal turret was
replaced by a "big calibre" (40mm?) gun in the radio compartment and the waist gun
installations are said to have been made of one 20mm and two 12.7mm guns.
I think, especially the 40 mm gun installation is highly improbable, but nevertheless I would
like to know, if such modifications are known .


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I don't know about that one, but RAF Coastal Command had a 40mm mounted in a chin position on a B-17 for antisub work.
I'll try to find a photo.
Here's the B-17.
I've also some recollection of the 'big gun in the radio compartment'
There was a photo in Air Pictorial in about the mid/late 1950s, of a YB-40 and some discussion about how the "standard" YB-40 armament was not much more than the B17G, but that considerably heavier armament had been flown in waist positions. Perhaps someone can find the details?


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I'll have to check some references, but as I remember, the main differences between a YB-40 and a B-17G would've been the second upper turret and the dual, instead of single, .50-cal machine guns at the waist installations.

This engineer really can't see the Emerson turrets being fitted to the B-17, they don't fit the lines at all and the extra weight and drag would not help the aircraft.
In the mentioned letter, it is said, that the aircraft with the Emerson turrets had
only some inches between the tail and the ground. But keeping in mind the very
modest performances of the standard YB-40, this version must have performed
really abysmal ! Perhaps they were fieldmodifications ? Or just old, incorrect memories ?
Once again, these YB-40 versions were reported in two readers letters to the RAF Flying
Review, one of them enclosed sketches, which were redrawn by the magazines draughtsmen.
That's not exactly, what I would call a very reliable source ! A modification with Emerson
turrets, ok, but fitting a 40mm gun seems not very probable to me. And fitting two turrets
with 4 british small calibre guns didn't make much sense in my opinion, as the trend was
going to heavier weapons with greater range and power. But as both variants shown are
externally readily distinguishable from a standard B-17 or YB-40 on one hand, and on the
other hand are quite similar to each other, I think, it's not to unrealistic, that both eye
witnesses have seen the same aircraft, a YB-40 with new nose and tail turrets and perhaps
a 20mm gun instead of the second dorsal turret.

Just a try to distil the drop of truth in these sightings .. :-\
If anyone has old Air Pictorials from the 1950s, there used to be a monthly page of pictures of unusual aircraft. The YB40 was one of those. Whether they were indexed, I don't know. Memory says the waist gun positions were said to have triples: two mg and a 20mm. A bit of a handful, I would have thought?
"..the waist gun positions were said to have triples: two mg and a 20mm."
Yes, that's exactly the waist armament given in one of these letters, too.
And then the author counted a total armament of 31 (!) guns ... keeping
in mind, that a gun without ammo is more or less useless, I can't imagine
a combat role for such an aircraft. Perhaps it was just a testbed for gun
installations ! ;D


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elmayerle said:
Going the other way, there's at least one photographically documented case of where a B-17G nose was mounted on a B-24 airframe. Anyone got the references for that one? As I remember, it really didn't look too bad, though rather unusual.

William Green's book, Famous Bombers of the Second World War, has the picture. If the Mods think it's "fair use", I can try to post it here.
The YB-40 (I) does bear a resemblance to the Project Reed aircraft:


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Re: Boeing YB-40 and Reed variations

I have read these posts with a great deal of interest as the concept of the "convoy escort" bomber as it is referred to in many AAF documents is strange enough to appeal to my interest in the bizarre.

The concept of the heavily-armed escort bomber appears to have begun with the British who had asked for such aircraft when first notified about the B-29. By the time the U.S. got around to actually building such aircraft they had rejected daylight bombing and declared the escort bomber as basically nonsensical. They were to be proven correct in at least the latter assertion.

I have in my collection at least five variations and earlier iterations of a B-17 convoy escort predating the ultimate configuration of the XB and YB-40. None are similar to those drawings earlier in this string. In fairness, those are supposedly of Reed Project or similar experiments. The detailed drawings in my possession go from the odd to the "overloaded to the point of failing takeoff" due to the amount of turrets and guns placed in them, plus a number of turret types that were completely new to me and that I've yet to see mentioned in print.

Virtually every heavy bomber project of the early war had "convoy escort" versions at least on paper and I have these as well. The exception appears to be the B-29, but I DO have a B-29 night fighter version proposal that could have easily been used in this capacity. And yes, I'm serious. A B-29 night fighter.

One of the more important aspects of the growth of this concept is that there is a substantial amount of discussion about "convoy escorts" prior to the U.S.'s entry into the war. It is clear from the documents that despite any public utterances to the contrary, the AAF was quite concerned about the bombers' ability to reach the target and return without armed escort. This concern was obviously well-founded, but the story of fighter escort has been discussed with varying degrees of accuracy many times. In the end, there were pretty close to a dozen different "convoy escort" concepts floated around during WWII.

Originally, the B-40 was to have been powered by Allison V-1710s. However, the testing and modification process was taking so long that the AAF asked for a "quick and dirty" conversion to existing airframes that would do the job. When the XB-38 eventually appeared, it was found that the aircraft was substantially faster than the standard R-1820-equipped B-17 of the time, but the additional weight of the Allisons and their cooling systems reduced the range to an unacceptable amount. One can only imagine the impact on range had the aircraft been saddled with the additional turret and gun weight of the B-40 both coming and going to target.

As for the Reed Project, I have copies of the original papers on this aircraft. I've not studied them at length as I'm tied upon on other projects right now, but what I can say is that the aircraft that eventually became known to us as the Reed B-17 had undergone a number of earlier modifications as well. What we see is the final iteration, not the first and only. Once again, none of the photos in my collection show anything approximating the earlier drawings posted here.

All of the above information will appear in print, as well as some other tidbits you will hopefully find interesting. When I finally finish "Consolidated Mess, Vol II" I shall start on the book that will have the above. I am currently putting together the next chapter of Mess, II, which deals with ditching. As with what seems to be EVERYTHING about the B-24, this is much, much more involved than I could have imagined. I can say that the ditching of the B-24 was an issue that was never resolved.

I hope the above proves of interest. I will gladly answer questions, but I'm sure you can appreciate that I'm not going to give away the entire contents of the book here!

Keep 'em flying and thanks for dropping by.

Have you dug up any information on the TB-24L's and RB-24L's B-29 gunnery trainers? All I have ever seen about them are the photos by William Larkins of them in a bone-yard.

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