Douglas DS-312 and DS-312A (XP-48): two very different birds...

[Apteryx]

...there is a lost link which is crucial to understand US Fighter evolution in the late 30's. This is the Douglas DS-312A which led the way with its nose free configuration. It was so influencial that most of the R-40C Pursuit Interceptors (including the winner designs XP-54, 55 and 56) were nose free.

Can anybody give any info or drawings of this aircraft?

Hello--I've just found this wonderful site. You may be aware of this, but there's a 3-view of the DS-312A in the August, 1996 issue of Wings magazine ("Hap Arnold"s Ghost Fighters") Basic and without dmensional information, apart from a human figure. If you've got more than that, I'd be delighted to know.

I also am intrigued by the Lockheed L-134-3 picture you posted. What a beast! Do you have dimensional info on that? One might guess that the outer wings are the same as on the XP-58 and scale off them.

 

[Antonio]

"Hap Arnold"s Ghost Fighters"

Welcome to the forum Apteryx

What's the subject of this article? Which aircraft are described?. Could you give us more details?. That back issue is available so I'd like to order it if I can get interesting info from it.

Cheers

Antonio

 

[Apteryx]

Hi--here's the Douglas DS-312A 3-view.

In answer to Pometblava, the article, "Hap Arnold's Ghost Fighters." is an overview of US piston-engine fighter designs of unorthodox configuration, starting with DS-312A and focusing on R-40C planes but touching on most everything unconventional. XP-52, -54, -55, -56, -67, -69, -71, -75, and others. Although there's not a lot I haven't seen elsewhere, I'd recommend the article to anyone interested in this subject.

 

[Antonio]

Hi--here's the Douglas DS-312A 3-view.

Oh my God...that was totally unespected!!. Thanks a lot Apteryx...Magazine ordered

 

[smurf]

Magazine ordered

Please, where from??

 

[lark]

'Hap Arnold's Ghost Fighters'

Wings/Airpower - August 1996

see : wingsairpower.com/backissues/date.shtml

Success.

 

[lark]

Thanks Apterix

Good work!

 

[smurf]

Once again, thanks, to all involved

 

[Stargazer]

I have a question which I hope hasn't already been answered elsewhere on this forum. Couldn't find it through the search engine, anyway...

Douglas unsuccessfully proposed their DS-312 (Design Specification 312), a lightweight fighter of the same class as the Bell XP-77 and the unbuilt Tucker XP-57; also with an inline Ranger engine. The DS-312 (sometimes found as 312A) received the designation XP-48, but eventually was canceled before a prototype could be built.

Now I have a second Douglas project in my files that has been designated (probably erroneously) as the Model 312, but it doesn't look one bit like the XP-48. It is a pusher aircraft of much greater size with two-counter-rotating propellers at the back. I believe this was submitted against the XP-54, -55 and -56 designs, but I'd need confirmation.

So what exactly was this aircraft project called, and do we have more information about it on this forum or on the web?

Thanks very much to anyone who can help!

 

[Stargazer]

Douglas DS-312A.

See page 4 of this thread please...

Yeah, I remember that page from a few weeks ago. But it still doesn't account for the fact that #312 applied to two totally different designs! Makes me wonder if there could be an age-old typo somewhere that got repeated over the years... Or maybe one is a DS- and the other isn't? By adding the letter "A", you'd expect a similar design, or at least a design made to the same specification... But here we have two entirely different fighters, different missions, different propulsion mode, different size!

 

[Pioneer]

Sorry but was the Douglas DS-312A pre or post Douglas XB-42 Mixmaster?
For obvious reasons!!!


Regards
Pioneer

 

[Antonio]

DS-312 was previous to Mixmaster

 

[Apteryx]

Yeah, I remember that page from a few weeks ago. But it still doesn't account for the fact that #312 applied to two totally different designs! Makes me wonder if there could be an age-old typo somewhere that got repeated over the years... Or maybe one is a DS- and the other isn't? By adding the letter "A", you'd expect a similar design, or at least a design made to the same specification... But here we have two entirely different fighters, different missions, different propulsion mode, different size!

In one respect, these two designs were similar. They both featured an unusually thin, high-aspect ratio wing which necessitated fuselage stowage of the main gear. The planforms of the wings match almost perfectly in the drawings below. Note that these two aren't to scale; I don't have size info on DS-312a.

These two designs are almost contemporaneous, though different. Maybe the designation was "extended" for bureaucratic reasons, e.g. the cancelled XP-48 project had left-over funds which someone simply applied to this follow-on design.

 

[Stargazer]

Wow, very conclusive, I guess. I had never seen a planform view of DS-312A, and it DOES match DS-312 a bit. From the drawings, -312A seems a lot bigger though (and especially taller, because of the contra-rotating props at the rear).

 

[Antonio]

At first sight it's easier to think in a typo, but since all sources seem credible, we have to admit that both designs share that DS-312 designation. I share Apteryx theory because rather different designs under the same number are not uncommon. Douglas could have used some elements of the XP-48 (wings and landing gear) into the later pusher fighter proposal and then keep it under the same model number.

BTW: nobody knows someone whose grandfather could have work at Douglas at that time and ask him about this projects?


Note: The XP-48 is not related to XP-57 or XP-77 submissions. They are all light fighters but never submitted together.

XP-48: early 1939 unsolicited proposal
XP-57: unsolicited proposal May 1940
XP-77: USAAC request to Bell for a ultra-light fighter study; October 30, 1941

Source: The American Fighter. Angelucci/Bowers

 

[Stargazer]

True. That's why I said "of the same class" and not "from the same requirement". Thanks for clarifying, though!

 

[Antonio]

You're very welcome.

 

[Stargazer]

I don't usually post my personal creations on this site... but this is one of those moments... ;D

(drum sound...)

My very first computer recreation... from scratch! B)

So far I've always adapted existing photographs... Not this time!
This time I've created everything using bits and pieces from various sources, but mostly the airbrush. I need to add that the paneling pattern and cannon inserts are my own invention. I believe since I mostly used an actual drawing of the project, this is okay for inclusion here... Only the name and designation are bogus... [EDIT: removed that bit from the picture]

Of course the background is just a photograph found on the web... :

Hope you guys like it!

 

[lark]

This is welldone already...but why a bogus name and designation?

 

[Stargazer]

This is welldone already...but why a bogus name and designation?

Ha! Because this was first published on the What-If Modelers forum... a place which is used to that sort of stuff... "Skyfighter" follows Douglas' standard practice of naming many of their aircraft by names begining with "Sky" (Skytrain, Skymaster, Skywarrior, Skyray, Skylancer, Skyhawk...) while "fighter" is an evocation of the mission of the aircraft, which went beyond that of a simple P- for pursuit aircraft. "YP-48A" indicates that this is a different type than the original XP-48 proposal, in the same way that the YP-59A differed from the original twin-boom XP-59 project.

Actually I didn't think of mentioning that it was a bonus designation and name because I thought this was obvious from the above posts... Now if this imaginary identity poses a problem here I can modify the file, no problem. [EDIT: I HAD actually mentioned it in the initial post! But anyway, I've modified the picture to lift all ambiguity]

 

[smurf]

Actually I didn't think of mentioning that it was a bonus designation and name because I thought this was obvious from the above posts... Now if this imaginary identity poses a problem here I can modify the file, no problem.

Yes, please modify. Someone will copy your beautiful drawing but not take the rest of the posts with it. 5 years on ... ...some other thread will be discussing whether it is real or not.

 

[Stargazer]

Done.

 

[Apteryx]

Sweet. This plane would be a good subject for a 3D modeling app--it's got intriguing and strange proportions. My skills in this department aren't adequate to the task, but maybe someday...

Actually, that's probably the secret wish of most of this site's posters...

 

[ACResearcher]

Does anyone have dimensions for the Douglas DS-312A pusher project?

Thanks in advance.

AlanG

 

[Stargazer]

Here is a picture that gives a good notion of the size:

 

[ACResearcher]

Thanks. I have that drawing as well as some others. I was hoping someone had the specific dimensions rather than having to do a "best guess" assumption.

AlanG

 

[Jemiba]

... rather than having to do a "best guess" assumption.

Well, that's a problem, I'm facing relatively often. Maybe somebody has found a chart or table giving
the avearge body height of men over the last, say 80 to 100 years ? Could be helpful for at least better
estimations from such drawings.

 

[ACResearcher]

The standard pilot/crew height used in every GA I've seen has been 6'. So if I use that as a basis (and hope that whomever did that drawing did the same), then I can come up with a fairly close approximation.

Or....

I could send an email to Pat McGinnis at the Douglas Archives and pray to the Aviation Research Gods that I get a response.

Better get out my ruler...

 

[Jemiba]

... and hope that whomever did that drawing did the same...

Very true ! That somewhat reminds me to one of our profs at the college, who marked results
for dimensionings of electric/electronic circuitries given with fractional digits simply as "wrong".
There was no such precision in reality. Think, it's pretty much the same here, so you're quite right.
But it gives the feeling of having done whatever was possible and at least in more recent drawings
the increased body height nowadays should be considered.

 

[Justo Miranda]

Allison V-1710-13 (pusher) width:744 mm.
fuselage width approx:750 mm.
proportional wingspan:10250 mm.
proportional lenght:7360 mm.
pilot:Myckey Rooney (1452 mm.) ;D

 

[ACResearcher]

LOL

Brilliantly done, Justo!

This makes me wonder if I should look at the fuselage diameters of the P-40 and the P-39 as a starting place. All the Mickey Rooney-types were being saved to be ball gunners!

Wink wink nudge nudge nudge

Alan

 

[Justo Miranda]

LOL

 

[Jemiba]

"Reconstruction of dimensional data" could be a worthwhile theme here on its own ! Justos example
shows the problems very well and assuming, that the draftsman always used the "standard pilot"
can be leading into the wrong direction. Especially when we think of cases, where even professional
models of ships probably were equipped with helicopter models in the wrong scale !
(http://www.secretprojects.co.uk/forum/index.php/topic,10313.msg167198.html#msg167198 #41)

 

[ACResearcher]

I finally took the 3-view drawings that have been floating around and measured the pilot. Assuming the pilot is 6 feet tall, he is almost exactly 1 inch in height, making the drawings 1/72 scale. Using that as an assumption I then proceeded to measure certain areas (wing tip to wing tip, horizontal stab tip to tip and nose to propeller tip - using the outside of the line thickness as my baseline).

Before sharing those numbers, I also took into consideration a variety of then-current design preferences shown by Douglas at the time. The first thing is the long, thin high-aspect wing. One sees this same general wing on DS-312, the A-26, the XB-31 the A/B-42 and the B-43. Indeed, one could even stretch to the point to include the C-124.

Good so far. Second, the general fuselage layout with the counter-rotating props at the tail, the shape and layout of the horizontal and vertical stabilizers, the placement of the engines and the placement and design of the main landing gear would all appear again on the A/B-42.

Finally, the "actual" wing span was comfortably within the range of other fighters of the time, even given the small chord of the wing.

So here is what I came up with for the general dimensions of the DS-312A:

Length: 31ft 10in (9705.6mm)
Wing Span: 42ft 8in (13004.64mm)
Tail Span: 13ft 3.75in (4057.92mm)

I'm certainly comfortable with both the assumptions and the final results. Now, having redone the drawings to my satisfaction I can expand the drawings into 1/48 or even 1/32 scale (or even 1:1) with no problems.

And there you have it - an enjoyable and informative - if mildly tedious - exercise. I hope you've enjoyed following it along.

AlanG

 

[Stargazer]

Topic split from an old "US piston fighters" topic.

 

[sienar]

Found a blurb on the NTRS, notable for listing the weight;
[/size]

[/size]In 1939, Douglas proposed to the Army a small, high-altitude fighter designated XP-48. Gross weight was 3400 pounds,
[/size]aspect ratio was 11, maximum wing loading was 37 pounds per square foot. The [/size]airplane was never built.
[/size]
[/size]http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19830018514_1983018514.pdf

 

[Stargazer]

Topics merged.

 

[leaded50]

been a subject in modellers/ airplane intertersting ones in some years..... and all scetches with minor changes. Even at the UK/Gertman model.

 

[leaded50]

here is my model build......

https://www.secretprojects.co.uk/threads/douglas-ds-312-a.39284/

I used the 3D drawing view here to build it.