OS-111 & XVA(H1) Navy Heavy Bomber projects (alternatives to Skywarrior)

[Orionblamblam]

No specifications, no data, sorry !
I've just used Tophes method for extracting 3-views from perspective pictures

Well done. Now, estimate dimensions based on comparison with the Vought Cutlass's shown on the aircraft carrier model, and you'll be done!

 

[lark]

Excellent! More than a few people will be happy to see this...

 

[Jemiba]

"..on comparison with the Vought Cutlass's shown .."

Aaah ! Am I'm getting old ? Am I getting blind ??
Nevertheless, thanks for the clue !
A very inaccurate estimation : length about 24m ( 80ft),
span about 25 m (82ft).
one pixel more or less means at least 2 meters more or less ...

 

[Artie Bob]

Possibly two reference dimensions could be the diameter of the rear radome and the length of the engines.

Best regards,

Artie Bob

 

[Orionblamblam]

Here's what I came up with:
Step 1: resize image by a factor of three
Step 2: draw wingtip to wingtip lines from one bomber to the next, carrying lines forward (see Note 1)
Step 3: Draw tip-to-tip line across span of Cutlass, and carried it across
Step 4: count pixel width: Cutlas = 73, Curtis = 166
Step 5: Pixel ratio = 2.274
Step 6: http://aerofiles.com/_vot.html => XF7U-1 wingspan = 38'8"
Step 7: Curtis span = 38'8" X 2.274 = 87.9 feet / 26.8 meters (see note 2)

Note 1: Carrying lines forward to parallel with the Cutlas helps to correct for perspective
Note 2: A3D Skywarrior span = 76'4". Given the heavier weight of the Curtis, this difference in scale makes sense.

Feel free to correct where appropriate.

 

[Tailspin Turtle]

Good teamwork! I had not made the connection between the Forrestal picture and the Curtiss proposal. Note that the computation and the picture supports an outrigger tread of 40 feet, which is a known...

Here is the Martin Model 245, which may have been one of the non-compliant proposals - two-man crew and no folding, among other

Picture courtesy of Glenn L. Martin Maryland Aviation Museum

 

[Tailspin Turtle]

The Navy's summary of the OS-111 competition briefly mentions the Lockheed proposal. It was powered by four J40s and at a gross weight of 100,000 pounds, had only 1/2 the mission radius desired. Lockheed also didn't bother submitting a cost quotation.

 

[overscan (PaulMM)]

Consolidating the many topics we've had on this over the years.

From Tony Buttler, the Republic OS-111 contender was NP-50, but he hadn't found any drawings of it as of last year.

Definitely nice teamwork. Jens, the drawing looks very nice indeed.

 

[nugo]

Hi Tailspin Turtl!

Martin Aircraft Model Designations, Built and unbuilt

M-245----Two place long range special attack monoplace
M-245-1--Basic airplane component with droppable hull
M-245-2--Basic airplane component with droppable launch gear
M-245-3--Basic airplane component with retractable gear
M-245A---Alternate carrier-based plane
M-246----Carrier-based attack bomber

I think, that the competitor was M-246

 

[Tailspin Turtle]

All I know is from a 21 February 1949 BuAer memorandum: "The Martin design was the carrier landing version of their Model 245, submitted in the 'Special Attack' design competition. No attempt was made to meet the specification requirements in regard to number of men in a crew, access to bomb bay, protected fuel tankage, folding wings, or provision of a turret. Incorporation of these items would increase the gross weight well beyond the specified 100,00 lb maximum." This, combined with the very limited attempt to meet the requirements, suggests that the Navy memo is describing the 245A. A 246 is listed in Martin records but I haven't seen anything that describes it, the time period it was created, or the requirement that it was created for.

 

[jackehammond]

Folks,

I read an article on the Arvo Valient and it mention that General LeMay was considering it for launching from US carriers. I would have loved to have seen the look on the air bosses face if a Vailent was operating from his carrier deck!

Jack E. Hammond

.

 

[overscan (PaulMM)]

Second M-245 pic from Tommy's blog.

http://tommythomason.com

 

[Jemiba]

A provisional drawing of the Martin M-245, maybe grade 2, based on the two artist impressions
posted by overscan and Tailspin Turtle. I would assume, that the version with the droppable hull
would have been brought to its launching point by a submarine (or what are those structures on
the shown sub) and landed back on a land base ?
I couldn't find any clue of the position and size of the weapons bay and, of course, length and
span data would be great ...

 

[Tailspin Turtle]

Sorry about that. Hope you didn't spend too much time on your drawing.
The submarine was used only for refueling enroute...
SAC Drawing from Glenn L Martin Maryland Aviation Museum

 

[Jemiba]

The 245-1 really is a surprise, the hull is much bigger, than I had thought, I'm really wondering,
how it could have get to the altitude shown in the artist's impression. Is there mentioned, if
the 245-1 had a conventional undercarriage ?
And the 245A is a good test for my method, with reagrds to the basic matrial, I'm quite content
with the result.

 

[Tailspin Turtle]

This is less complicated than I thought. The 245 was the basic airplane with no landing gear. The -1 had a droppable hull. The -2 had a droppable landing gear and was for one-time usage. The -3 had retractable landing gear and was only for test and training. The 245-A had a retractable landing gear and tail hook for return to a carrier. The 245-1A was the carrier-compatible airplane with a droppable hull. After the -1 dropped the hull or the -2 the landing gear, it became a 245 and was committed to ditching. There were various mission scenarios incorporating refueling in-flight, from a submarine, and/or on-board an aircraft carrier.

 

[TinWing]

And the 245A is a good test for my method, with reagrds to the basic matrial, I'm quite content
with the result.

Indeed, your drawing looks better than the original from Martin.

 

[Orionblamblam]

And the 245A is a good test for my method, with reagrds to the basic matrial, I'm quite content
with the result.

As well you should be. To get that close based on nothing but paintings is really quite remarkable.

 

[Skybolt]

mm, I think Stan has ended the job of photographing the big "project books"....

 

[Jemiba]

"As well you should be. To get that close based on nothing but paintings is really quite remarkable."

It shows, that the artist, hired by Martin, had done its job very well, without too much "art".
Unfortunately, nothing, you can be sure about ..

 

[mattrix]

No specifications, no data, sorry !

Good work Jemiba! I have just been browsing through excellent "Secret Aerospace Projects of the US Navy, Volume 1: The Incredible Attack Aircraft of the USS United States, 1948-1948" by Jared Zichek and it seems, that the Curtiss-Wright machine in question was Curtiss-Wright P-558 (see pp. 35 through 49). You can find there also exhaustive information on this machine and lots of factory BPs.

 

[overscan (PaulMM)]

Douglas Model 593 (early Skywarrior)

From

http://tommythomason.com/

 

[hesham]

Hi,

for the Vought,I think its proposal was V.364.

 

[Stargazer]

Using the Spangenberg Index, and what has already been exposed in this thread, it seems that the list of contenders for OS-111 (dated November 1948) was as follows:

• Consolidated Vultee (designation unknown)
• Curtiss-Wright P-558
• Douglas 1181
• Douglas DS-593, 593-1, 593-2
• Fairchild M-130
• Lockheed L-187-2/-3?/-7
• Martin 245
• Northrop N-59
• Republic NP-50
• Vought V-364

There is also a Douglas 594 (and 594-1, 594-2, 594A) which could have been from the same competition.

 

[overscan (PaulMM)]

Using Jared's book (based on National Archive materials)

OS 111
Convair Carrier Based Landplane Class VA - Long Range
Curtiss-Wright P-558
Douglas (El Segundo) Model 593
Douglas (Santa Monica) Model 1181
Fairchild M-121/M-128
Lockheed L-187
North American RD-4554
Republic NP-50

OS 115
Convair Class VA Long Range Special Attack Airplane
Douglas (El Segundo) Model 594
Douglas (Santa Monica) Model 1186
Fairchild M-130
Martin Model 245

These (afaik) are the submitted bids. This doesn't rule out other designs being drawn up to one or other of these specs, for example Northrop did a series of preliminary designs, but they weren't submitted.

 

[Tailspin Turtle]

Curtiss-Wright P-558 submitted for OS-111 that resulted in the A3D. It came in second to the Douglas El Segundo proposal.

 

[hesham]

Great find my dear Tailspin.

 

[RAP]

Very nice. Beautiful aircraft.

 

[Bill S]

Here is a general arrangement of a swept wing bomber with the V-364 designation.
Not much detail, no alighting gear or arresting gear shown. VAHF archives.
I am not sure this ever became a developed proposal to the Navy.


I hope this adds something to the discussion.


bill

 

[hesham]

Great find Bill,thank you for sharing.

 

[overscan (PaulMM)]

Certainly fits designwise with some of the other contenders.

 

[Tailspin Turtle]

Here is a general arrangement of a swept wing bomber with the V-364 designation.
Not much detail, no alighting gear or arresting gear shown. VAHF archives.
I am not sure this ever became a developed proposal to the Navy.

I hope this adds something to the discussion.

bill

Bill - great find. High aspect-ratio wing for range like the Curtiss. Two J40 engines (bifurcated inlet). Big bomb bay for the weapon (rectangle at mid fuselage). Hard to figure out where the landing gear stowed given what appears to be the location of the fuel tanks fore and aft of bomb bay. There is what looks like a partial arc under the rear fuselage that would correspond with the tailhook travel.

Can you read the dimensions on the original?

Vought didn't propose in the end. (Maybe they couldn't figure out where to put the landing gear.)

 

[Bill S]

Tommy,


Not all the measurements are listed.
Length is 87' (1044")
Height from static ground line 14' 10" (178")
Wingtip width 70"
Verticals span is 23' (276") at the tips
Span is not listed
The distance engine centerline to centerline is also not given.
Two Improved J-40's @9300lbs static thrust


bill

 

[Tailspin Turtle]

Bill - Thanks very much for that. A fairly rigorous evaluation of the V-364 drawing you posted (I had to stretch it in height based on the front view and the ground line to tail tip measurement) gives a wing span of about 93 feet, give or take a few inches. Based on the other proposals, there doesn't seem to be restriction on span like there was on gross weight.

 

[Mark Nankivil]

Great stuff Tommy and Bill - thanks for sharing it.

Tommy, what's your take on the tandem gear arrangement for carrier landings? B-47s and B-52 had some rather limited parameters to meet for the landing attitude and I see such requirements tough to meet when it comes to carrier landings.

Enjoy the Day! Mark

 

[Tailspin Turtle]

The Navy evaluation stated that the bicycle gear was "probably satisfactory for field landings but is an unknown quantity for carrier work". My impression is that there was no particular difficulty landing either the B-47 or the B-52. The U-2, of course, is notoriously difficult to land (there are You Tube videos of excursions off the runway) but that is in large part because it has a very low wing loading: if you touch down on the forward wheel first with any sink rate, you'll almost certainly get a bounce with ugliness to follow; touching down on the aft wheel first is no bargain either. The first attempt at landing a U-2 on an aircraft carrier without the benefit of a tailhook (the thought was that with the customary wind-over-deck the tailhook wasn't necessary) almost ended in disaster. With a tailhook, the U-2 was probably easier to land on the carrier than ashore.

 

[hesham]

Hi,


is that a real drawing to NAA OS-111 ?.


http://bbs.stardestroyer.net/viewtopic.php?style=4&f=9&t=145479&start=100

 

[Tailspin Turtle]

Yes

 

[hesham]

Thank you my dear Tailspin.

 

[blackkite]

Hi!

http://bbs.stardestroyer.net/viewtopic.php?style=4&t=145479&start=100