US Bombers

[hesham]

Anther Projects submitted to this Specification (39-640);

Burnelli XBA-1
Chance Vought VS-302
Consolidated LB-22 & LB-24
Martin M-178

American Secret Projects: Fighters, Bombers, and Attack Aircraft, 1937-1945

We find Stearman X-100 was appeared in 1938 and X-120 was shown 1941/42,so the Stearman proposal for
this contest maybe X-110 ?.

We forget Douglas,may it was D-503 ?.

 

[drgondog]

My little summary on US Heavy Bomber Evolution from 1934 to 1945

Additions, corrections, etc...will be wellcome as usual

Antonio


Sources:

International Air Power Review Vol.4, 5 and 13. Airtime Publishing

US Bombers 1928 to 1980s. Lloyd S. Jones. Aero Pub

Magnesium Overcast. Dennis R. Jenkins. Speciality Press

Giants of the Sky. Bill Gunston. PSL

B-29 Superfortress. Part 1. Detail & Scale Vol. 10. Alwyn T. Lloyd.

Boeing Aircraft since 1916. Peter M. Bowers. Putnam

B-29 In Action

B-24 In Action

B-17 In Action

B-36 In Action



By 1934, when Billy Mitchell young devotees had risen to decisive positions in the USAAC it was time to develop the long range bomber concept.
In 1934 it was officially launched as Project A. Influenced by the Soviet ANT-20 supposed performances, a 5,000 miles (8000 Km) range was requested for the Project A design. (In fact this was 6 times the real figure from the ANT-20)
Project A was intended to carry out defensive operations in Alaska, Hawaii and Panama from CONUS bases.
Submissions came from Boeing and Martin.

Experimental Long Range Bomber (Project A)
Allison V-1710-3 in-line engines were specified for both designs. 1000 hp

XB-15. Boeing Model 294. A flying wing layout was also studied.
XB-16. Martin Model 145 initial layout. In 1935 layout changed to twin boom configuration.

1934, August. Boeing developed Model 299, a scaled down derivative from Model 294 design work to enter the USAAF new multi-engined bomber competition. The aircraft was designated XB-17. This program was conceived not for a long range bomber but a coastal defence aircraft capable of attacking enemy warships.
Model 299 range was 3000 miles. It was powered by P&W Hornet radials. 750 hp

1935, February. The USAAC announced Project D for the development of a Very Long Range Bomber. Project D had to push the limits one step beyond from Project A. A prototype was expected to be ready for March 1938.
Submissions came from Douglas and Sikorsky
Allison XV-3420-1 in-line engines were specified. 1600 hp

Douglas (Model number unknown to me)
Sikorsky restricted project No. M5-35

1935, summer. Both Project A and D merged under the BLR prefix.
Boeing XBLR-1
Douglas XBLR-2
Sikorsky XBLR-3
Martin never get the XBLR-4 designation because it was cancelled.

1935, July. XB-17 made its maiden flight.

1936. XBLR-3 was also cancelled and Boeing and Douglas designs get the B prefix.

Boeing XB-15. Powerplant specification changed to P&W R-1830 Twin Wasp radials. 1200 hp
Douglas XB-19. Powerplant specification changed to Wright R-3350 radials. 2000 hp

1937. XB-15 made its maiden flight while XB-19 suffered delays because Douglas priorities concentrated in other designs. USAAC ordered them to go ahead with the project.
The XB-15 was underpowered so a P&W R-2180 version was considered under the designation Y1B-20 but later cancelled.

1938, March. Boeing offers a new long range bomber based on XB-15 experience. Boeing Model 316 is designated Y1B-20 (second use for this designation) and later XB-20. Several variations studied with Wright Cyclone (1350 hp) or P&W R-2180-5 (1400 hp) engines. The project was cancelled. Model 334, a pressurized B-17 derivative with tricycle undercarriage was also considered.

1938 USAAF requested Consolidated for heavy bomber with a performance exceeding the B-17. The answer was Model 32, B-24

1939, January. USAAC asked Consolidated to create a new production outlet for the B-17 but they replied with a counter-offer, the Consolidated Model 32 which was accepted as the XB-24 (Powerplant: P&W R-1830-33 Twin Wasp radial. 1200 hp).

1939, July. First B-17B delivered

1939. Boeing continued studies on a Long Range Bomber under Model Numbers 334A and 341.

1940, January. USAAC issued a requeriment for what it was known as the “Superbomber”. Range: 5333 miles. Speed: 400 mph.
Submissions came from:

XB-29: Boeing Model 345 (the latest refinement of the Model 316 and Model 341 line)
XB-30: Lockheed Model 51-81-01
XB-31: Douglas Model 332F
XB-32: Consolidated Model 33

The figures for the XB-29 were Range: 5830 miles. Speed: 365 mph. Powerplant: Wright R-3350-23 radials (2200 hp)

1941, April. A competition for an intercontinental bomber was initiated. In the case of a German invasion of the UK and USA involved in the War against Germany, a bomber capable of operations from America against Europe would be needed. Required range was 10.000 miles.

Proposals came from:

* Consolidated Model 35
* XB-36: Consolidated Model 36
* Consolidated Flying Wing Bomber
* Boeing Model 384
* Boeing Model 385
* Boeing twin boom bomber(Model Number unknown to me)
* XB-35: Northrop (Model Number unknown to me)
* North American NA-116
* Burnelli B-2000B

With the fortunes of War, the project lost its priority. The attack on Pearl Harbour shifted priority to B-24 and XB-32. In September, 1942 highest priority was required again but this time not for the European theatre but this time to fly across the Pacific. Nevertheless, until the cancellation of the B-32 production, the project received little interest.

1941, summer. XB-19 made its maiden flight.

1942, September. B-29 first flight.

1946, August. B-36 First Flight.

I know this is an old thread, but slipping the Model 299 in as a "3000mi range Coastal Defense aircraft" to attempt to neutralize the immediate hue and cry from USN at Congress to halt funding, was one of the greatest jokes (successfully) perpetrated by US Army Air Corps Materiel Division.

So, with a fast, high altitude capable aircraft with ceiling far above any conventional pursuit (land or sea based) and a 3000 mi projected range and maybe a 900mi (combat radius) with a full load of bombs - the USN was supposed to believe its only conceivable use was 'coastal defense'?? The graduates of the School of Applied Tactics were permeating rank in the USAAC and the B-17 was the 'camels nose under the tent'.

 

[drgondog]

The NA-98X was a private venture. There was no designation because the USAAF never ordered the aircraft (the Army Air Force probably regarded 43-4406 as a trials B-25H on loan to manufacturer).

According to Baugher, the NA-98X failed because the R-2800s gave it power beyond the airframe's structural limits. Obviously, giving the design the entirely new wings that it needed would have defeated to objective of providing a cheaper alternative to the A-26.

http://home.att.net/~jbaugher2/b25_16.html

Old thread, but I doubt Baugher's claim. NAA had plenty of 'prior' art and analysis for R-2800 level power in the XB-28 program. My sources state that the pilot went off the reservation and exceeded the placard N limits.

Engine power doesn't kill - Q loads and a high speed pull out and maybe a little too much enthisiam on the rudder may have been the root cause. That said I have never found the accident report.

 

[drgondog]

You'd need some some strong fuselage frames in that area to carry the wing loads as sell as frame the bomb bay. I'd think the design would lend itself more to bomb bays ahead of and behind the wing carry-thru structure (the one ahead of the wing would likely be much like the Orion's weapons bay (as compared to the airliner it was derived from, the Electra) and the one behind the wing would be similar. I rather suspect the major lines would've remained the same between the L-09 and the B-30, allowing some of the same jigs and fixtures (possiibly even some of the same skin panels) to be used, but the structure likely would have needed redesigning to military standards. I see this more as an adaptation of existing and proven lines rather than a simple conversion.

For large bomb/droppable stores, you will always place your primary disposable load as close to Cruise center of gravity as possible - which would be in region of 25% mean aerodynamic chord

 

[BlackBat242]

That link for Baugher's Model NA-98X page is dead - here is a good one:

North American NA-98X

And his entry does not blame the engine, but rather the aircrew:

It was recognized that the increased power of the R-2800 engine, acting in concert with the increased aileron area and reduced stick forces, might make it possible to operate the aircraft in performance regimes where excessive bending moments could be imposed on the wings, maybe even leading to a catastrophic failure and loss of the aircraft. Consequently, during flight testing, it was agreed that the maximum airspeed would be restricted to 340 mph and the normal acceleration would not exceed 2.67g.

On April 24, 1944, the NA-98X was taken up for a test flight by Maj. Perry Ritchie and Lt. Winton Wey. During a low speed pass over Mines Field, the aircraft disintegrated in mid-air and crashed, killing both pilots. An investigation showed that both outer wing panels had been ripped off the aircraft during the low-speed pass, the plane having been flown beyond its structural limitations by its crew. Following the crash, all further work on the NA-98X project was abandoned.

 

[BlackBat242]

Its not "his take" - it was the conclusion of the engineers involved in the project that restrictions needed to be placed because the engines installed, combined with changes to the ailerons, could power the aircraft into a dangerous flight regime that the original engines and ailerons could not.

Restrictions which the flight crew then apparently exceeded - fatally for the aircraft and themselves.

 

[sienar]

Consolidated model???

from; https://www.worthpoint.com/worthopedia/consolidated-convair-original-folders-3832750773
and; https://www.worthpoint.com/worthopedia/consolidated-convair-original-folders-3832750773

 

[lark]

The first drawing should be.
..... Twin engined version of the B-32 offered in April 1945.

Source : p.149- Robert E. Bradley : ' Convair Advanced designs 1923-1962'
no model number in the text...

 

[hesham]

The first drawing should be.
..... Twin engined version of the B-32 offered in April 1945.

Source : p.149- Robert E. Bradley : ' Convair Advanced designs 1923-1962'
no model number in the text...

That's right my dear Lark,and the second is exactly the same in page # 172.

 

[drgondog]

That link for Baugher's Model NA-98X page is dead - here is a good one:

North American NA-98X

And his entry does not blame the engine, but rather the aircrew:

Joe passed away recently. I have no idea if anyone remains to maintain his website or protect the data.

 

[GTX]

Joe passed away recently. I have no idea if anyone remains to maintain his website or protect the data.

See the following:

https://www.secretprojects.co.uk/threads/joe-baugher-serials-website-in-new-hands.42749/

 

[hesham]

From, Magnesium_Overcast_The_Story_of_the_Convair_B-36.

 

[Nahida1645]

From, Magnesium_Overcast_The_Story_of_the_Convair_B-36.

Hello.
Is there any existing dimensions for the Boeing 384 and 385?
The 384 looks like an upgrade of the 345 (B-29 family)

~ Nahida

 

[Antonio]

Source: Boeing B-47 & B-52 origins and evolution by Scott Lowther

Aproximate dimensions

Model 384 is from October 1942 Length: 43 m Wingspan: 64 m
Model 385 is from August 1942 Length: 53 m Wingspan: 73 m
For comparison, B-36 was length: 49 m wingspan: 70 m

Boeing Model 345 is from May 1940, XB-29 first flight was on September 21, 1942 and B-29 first operational mission was on 28 October 1944 so design experience from it consequently translated into series of "intercontinental bomber" designs

Consolidated was awarded in October 1941 with the contract for the "intercontinental bomber" competition issued on April 1941 while Northrop also received the go ahead to build a prototype of its proposal.

Boeing submitted some designs (Model 360, 361, 362 and 363) but continued with Model 384 and 385 studies after the competition ended.

In 1942 WWII was just begun for the US, the winner still to be decided, the B29 in early development and short ranged for operations against Japan...thus not a bad idea to go with additional intercontinental bomber designs, besides the B35 and B36.
Also Douglas has the Model 423, NAA the 116 and Martin the 194 and 203.

A new intercontinental bomber competition will start by August 15, 1944...
Again I strongly recommend the superb "Boeing B-47 & B-52 origins and evolution by Scott Lowther" and The B-52 competition of 1946 from Jared A Zichek.

 

[drgondog]

From, Magnesium_Overcast_The_Story_of_the_Convair_B-36.

Both the B-36 and C-124 engine roars at take off and the high altitude drone are forever in my brain from childhood.

 

[hesham]

From, Western_Aviation_Missiles_and_Space 1942,

was this just a hypothetical concept or what ?.

 

[Arjen]

From, Western_Aviation_Missiles_and_Space 1942,

was this just a hypothetical concept or what ?.

Looks like a North American B-25 Mitchell.

 

[hesham]

Looks like a North American B-25 Mitchell.

Or North American P-443 ?.

 

[Arjen]

@hesham I'm not familiar with the North American P-443, but the drawing you posted doesn't like anything other than a B-25 to me.

 

[Apophenia]

Or North American P-443 ?.

hesham: This is clearly advertisement artwork showing BF Goodrich's rubber contributions to B-25 production.

On the source, obviously it was Western Flying - Western Aviation, Missiles and Space didn't exist in 1942. But what was the volume and date?

 

[hesham]

hesham: This is clearly advertisement artwork showing BF Goodrich's rubber contributions to B-25 production.

On the source, obviously it was Western Flying - Western Aviation, Missiles and Space didn't exist in 1942. But what was the volume and date?

It's July 1942.

 

[hesham]

From, Western_Aviation_Missiles_and_Space 1942,

was this just a hypothetical concept or what ?.

From the same source.

 

[BlackBat242]

@hesham I'm not familiar with the North American P-443, but the drawing you posted doesn't like anything other than a B-25 to me.

Specifically something like a cross of the B-25A and -B. The first image posted shows a single tail gun and a single gun turret in the aft dorsal position - the -A had single guns on flex mounts in the dorsal, tail, side, and nose positions, while the -B and later deleted the side and tail guns in favor of a twin turret in the aft dorsal and ventral positions.

So it looks like someone took a drawing of the -A and attempted to update it for a dorsal turret, but didn't have full info on the changes.

 

[Hood]

As Apophenia has already said, these are just BF Goodrich adverts showing where their rubber products go on a "bomber". These are not projects or unknowns or anything else, just artistic licence.

 

[ACResearcher]

XB-31 revisited

Since there seems to be some question in some people's minds regarding my assertion that the Douglas entry for the XC-218A resubmission was the Model DS-332F, I've gone back into my files to provide some addition original-source materials that will hopefully put an end to it.

I have included two items here: One is a page from the R40B XC-218A Resubmittal section on Weight Analysis. This is the first page in the section on the AAF's weight analysis on the 332F. I have drawn arrows to specific areas to show this.

The second item is my redraw of the the DS-332F in flight, banking slightly to the left. This is a line-for-line reproduction of an original Douglas drawing found at NARA II, as was the document (and LOTS of others) referenced above and shown below.

I hope this will satisfy those who have continued to insist that the Model 423 was the XC-218A resubmission. My friend Lloyd Jones got that wrong, but given what he had to work with so many years ago we can appreciate his error and be glad he helped encourage serious, ORIGINAL SOURCE research.

AlanG