Keystone monoplane bomber

[tallguy]

Looking for any info on an unbuilt project of the early 30s for a Keystone monoplane bomber. NOT the Huff-Daland XHB-3 of 1926, although info on that would also be appreciated!

 

[hesham]

Hi Tallguy,

you get me back to some odd idea about what mentioned in old
encyclopedia about there was two Projects for Keystone,came after
its known series "LB",they are LB-15 and LB-16 ?.

 

[T. A. Gardner]

The LB 15 and 16 were designations for Long-Range Bombers, that became the Boeing XB-15 (single prototype) and Martin XB-16 (unbuilt). The Long-Range (it was originally the XBLR-15 and 16) Bomber designation was dropped during development, and these just became heavy bomber designs using the B (Bomber) designation.

 

[tallguy]

This would be the same competition that resulted in the B-9 and B-10

 

[T. A. Gardner]

The BLR competition was to design a bomber for continental defense. Initially, it was Boeing and Martin, but Martin backed out without building a plane. Douglas came in with the XBLR-19 (XB-19) after Boeing was already fairly well along with their design.
The specification called for a bomber of 200 mph to be able to fly coast-to-coast then out to a distance of 500 miles (a specified range of 5000 miles) to attack a target non-stop / unrefueled. Alternate uses were to be these could reinforce Alaska, Hawaii, or the Panama Canal zone flying from the US.
It was a very ambitious project, but the planes were let down by lack of powerful enough engines. Both the XB15 and XB 19 ended up being redesignated cargo planes in the 40's and were used in that capacity throughout the war. They also received much more powerful engines but neither ever proved fast.

 

[hesham]

The LB 15 and 16 were designations for Long-Range Bombers, that became the Boeing XB-15 (single prototype) and Martin XB-16 (unbuilt). The Long-Range (it was originally the XBLR-15 and 16) Bomber designation was dropped during development, and these just became heavy bomber designs using the B (Bomber) designation.

No,that was not right at all,the LB-15 and LB-16 were from Keystone
designation series,they are not related to Boeing or Martin concepts ?!,
but to be honest,they did not confirmed.

 

[tallguy]

So, this competition resulted in 2 engined "medium" bombers, not large b-15 type aircraft

 

[T. A. Gardner]

So, this competition resulted in 2 engined "medium" bombers, not large b-15 type aircraft

No, the LRB specification was pared down and the US got the B-17 then B-24 and that sort of 4-engine bomber. From there, the next generation was the B-29 / B-32 super heavy and the LRB became the B-36 program of intercontinental bomber.

 

[Apophenia]

No,that was not right at all,the LB-15 and LB-16 were from Keystone
designation series,they are not related to Boeing or Martin concepts ?!,
but to be honest,they did not confirmed.

In this context, the LB-15 and LB-16 were part of the 1924-1930 US Army Air Corps 'Light Bomber' designation sequence.

It is true that most LB designations were assigned to Keystone designs. But there were also designs from Huff-Daland (LB-1, XLB-3, and LB-5), Atlantic (LB-2), and Martin (LB-4).
-- http://www.joebaugher.com/Bdesig.html

 

[T. A. Gardner]

No,that was not right at all,the LB-15 and LB-16 were from Keystone
designation series,they are not related to Boeing or Martin concepts ?!,
but to be honest,they did not confirmed.

In this context, the LB-15 and LB-16 were part of the 1924-1930 US Army Air Corps 'Light Bomber' designation sequence.

It is true that most LB designations were assigned to Keystone designs. But there were also designs from Huff-Daland (LB-1, XLB-3, and LB-5), Atlantic (LB-2), and Martin (LB-4).
-- http://www.joebaugher.com/Bdesig.html

I'd say there was definitely some confusion with designations by the USAAC in the 30's then.

 

[airman]

Keystone designations are until LB-14 (B-5).

 

[hesham]

In this context, the LB-15 and LB-16 were part of the 1924-1930 US Army Air Corps 'Light Bomber' designation sequence.

It is true that most LB designations were assigned to Keystone designs. But there were also designs from Huff-Daland (LB-1, XLB-3, and LB-5), Atlantic (LB-2), and Martin (LB-4).
-- http://www.joebaugher.com/Bdesig.html

I know that dear Apophenia,

but as I mentioned before,an encyclopedia defined them as two designs for
Keystone,even it didn't clorify if they were a projects or not,could be a misprint,frankly I don't know ?!.

 

[Apophenia]

I know that dear Apophenia,

but as I mentioned before,an encyclopedia defined them as two designs for
Keystone,even it didn't clorify if they were a projects or not,could be a misprint,frankly I don't know ?!.

hesham: I was referring to your comment that "LB-15 and LB-16 were from Keystone designation series". My rather pedantic point was that the 1924 LB designations were a USAAS sequence, not "from Keystone designation series".

As for the LB-15 and LB-16 being unbuilt projects, I think they must have been. Or, put another way, we can trace all of the later Keystone 'B' for Bomber sequence designations: XB-1B was Huff-Daland XB-1 (re-engined); B-3 was LB-10A; B-4 was LB-13; and, B-5A was LB-14 (kind of).

 

[Apophenia]

I'd say there was definitely some confusion with designations by the USAAC in the 30's then.

For sure. Categories changed over time.

The USAAC inherited the Army Air Service's 1924 designation system revisions in 1926. They introduced the 'A' for Attack (instead of Ambulance) sequence and dumped the 'Light Bomber'/'Bomber (medium)' distinction which never made much sense anyway. That cobbled-together Army Air Corps designation system was changed again in 1930.

BTW, who was responsible for that later LB ('Land Bomber') designation sequence?

 

[Apophenia]

Sorry for the digressions tallguy. Back on topic ...

There's not a lot out there on this Keystone monoplane bomber concept. It was a submission to meet a 1929/1930 USAAC Circular Proposal for a new heavy bomber design. As submitted, the XB-908 was to be a low-winged monoplane of all-metal construction with a retractable undercarriage. A crew of five was carried with pilot and co-pilot arranged side-by-side. Power was to be provided by two Curtiss Conquerors (GV-1570-7?) - Keystone having just been merged into Curtiss-Wright. Armament consisted of three .30 calibre Browning machine guns and up to 2,000 lbs of bombs. The latter were to be carried externally, the XB-908 having no bomb bays.

The Keystone XB-908 (aka Travel Air Mono) was only built as an April 1932 wooden mockup. The Smithsonian has mention of it under 'The Curtiss-Wright Corporation Records Finding Aid':

TRAVEL AIR MONO: XB-908 Mock-up (Side by Side Arrangement)
Scope and Contents: Videodisc #7A14485-14493
-- https://sova.si.edu/details/NASM.XXXX.0067#ref9039

The Keystone design was the only candidate not to reach the hardware stage. The XB-908 was withdrawn by Keystone once it was clear that the design would not meet the Army Air Corps' requirement.

I presume that, when Keystone ceased operations in 1932, their designs were absorbed by Travel Air (which was merged into Curtiss-Wright in 1929). Stéphane also mentioned a 'Curtiss XB-908A'. I'm guessing that this 'XB-908A' was an unbuilt variant developed by Travel Air after Keystone's demise.
-- https://www.secretprojects.co.uk/threads/the-forgotten-x_-900-series.7573/

 

[lark]

Keystone XB-908 bomber project 1932

Description in 'American Combat Planes ' by Ray Wagner , page 102.
Mockup should have been constructed.

The Keystone bomber project was one of the several entries in a
request of the War Department 1928.
The winner of this request was in the end Martin with a design that would become the B-10.

P.S. the LB designator was also used by Consolidated for several light bomber /attack projects
in the late '30's. They stopped the use of to avoid confusion with the Air Corps designation system

 

[ACResearcher]

With regard to the Consolidated LB projects, there were at least 28 including two (IIRC) 4-engine bombers. One of these later 4-engine bombers eventually became the B-32 proposal/project.

Respectfully submitted,

AlanG

 

[ACResearcher]

The Army Air Service/Army Air Corps/Army Air Force went through a rather long series of designation changes during its history.

The first of these was a "Type" designation based on the type and usage of each aircraft. I don't remember - nor do I have the time - to dig out the documents about when various changes took place although I do have them.

Attached is the first designation series by Type.

Enjoy.

Respectfully submitted,

AlanG

 

[Stargazer]

Attached is the first designation series by Type.

Wouldn't hurt much to mention that I'm the one who did that research and provided the file in the first place! Here is the PDF...

 

[ACResearcher]

Sorry, Stargazer!

I was actually sent that page by someone else with no attribution.

Nice work!!

AlanG

 

[Stargazer]

Mention of the USAAC contract for the Keystone XB-908 bomber design.
A mockup was later built, and the project also appears elsewhere as the "Curtiss-Keystone XB-908-A", suggesting some modification along the way.