US Navy specification SD 112 : Grumman F7F competition

[Antonio]

Does anybody know enything about the competition that led to the USN. I realized that I have nothing but the Boeing Model 374 rival design.

Name and details of the request for proposals, contenders?

Anything will be welcomed

Antonio

 

[hesham]

My dear Pometablava,

all I know,that Navy want a twin engined fighter to Midway aircraft Carrier,
and the F7F was developed from XP-65 for future Convoy Fighter,in cancelling of
the earlier Grumman F5F,and for the Boeing Model 374,here it is;

 

[Tailspin Turtle]

More later (Note: the F4U was on the list as a size/performance reference, not a candidate.)

 

[Tailspin Turtle]

The Wallace-Martin huff-and-puff...

 

[hesham]

More later (Note: the F4U was on the list as a size/performance reference, not a candidate.)

Hi Tailspin,


do you mean,the aircraft in that list was the contenders of this competition ?,
here is from Stargazer,the McDonnel Model 6.

 

[Stargazer]

Fascinating list, Tommy, thanks for sharing.

A few thoughts:

• The Bell Model 22 is described here as a single-engine pusher aircraft with counter-rotating propellers. This likely makes it a close parent to the Models 19 and 20, but contradicts other information on the Model 22 which gave it as an early twin jet proposal...
• Brewster's design P-33A is well-known and appears elsewhere on the forum.
• The McDonnell Model 6 is probably the aircraft depicted in the above advertisement (hesham beat me to it!)
• The Vultee Model 79-C is a surprising designation because the Model 79 was the BT-13B VALIANT while the Model 79A was the Navy's similar SNV-2. I can't see the VALIANT being turned into a pusher aircraft... so why reuse the "79" number at all?
• Never heard of Wallace-Martin before... Any relation to J. V. Martin? Or (less likely) to Glenn L. Martin?

 

[Tailspin Turtle]

Hi Tailspin,

do you mean,the aircraft in that list was the contenders of this competition ?,
here is from Stargazer,the McDonnel Model 6.

My understanding is that those were the contenders except for the F4U, of course.

 

[Stargazer]

You've made my day, Tommy, this is beautiful!

Could the McDonnell Model 8 pusher proposal with counter-rotating propellers be the same as the elusive McDonnell "Manta" design?

 

[hesham]

Thank you Tailspin,


that means the competition which led to Grumman F7F was a huge,
and here is the Brewster 33.

 

[Stargazer]

Another picture of the design shown two posts above as the McDonnell "Manta", described here is as the "Bat" in a wartime German magazine.

Definitely corresponds to the description of McDonnell's Model 8 and to the general spirit of that competition.

 

[Stargazer]

From the same German magazine (Der Deutsche Sportflieger, September 1942), I believe the Snipe makes perfect sense as the Brewster 33E: the date fits, and the design is the same as the 33A except for the twin fins and counter-rotating props.

 

[Stargazer]

Okay, just found the (meager) description of the Bell Model 22 from the excellent Cobra! Bell Aircraft Corporation 1934-1946 by Birch Matthews (Schiffer) and realized that I actually had photos of that aircraft's mockup, mislabeled as the very similar Model 19... so here goes:

Model 22 was another proposal to the Navy for a modified Model 20 (XP-59). It was basically the same airplane and designed to use a submerged R-2800 engine, but structurally modified for carrier landings. The Navy apparently showed no interest.

If we consider that the Vultee proposal was very likely a navalized Model 78 Shrike (which evolved into the Model 84 Swoose Goose), what emerges from the whole set of designs is a strong twin-boom pusher pattern. We don't have the tractor proposals all depicted, but it would seem that the Tigercat and Boeing Model 374 seem quite different. So my question is: could it be that the Boeing Model 352 and the other submissions in the list could have been submitted to an early version of the tender, with perhaps and early and different G-51 design, and that the Model 374 and the G-51 Tigercat as we know it were submitted later to a modified tender?

 

[Antonio]

OMG, that's SPF style

Thanks everybody for the help.

 

[Tailspin Turtle]

Thank you Tailspin,


that means the competition which led to Grumman F7F was a huge,
and here is the Brewster 33.

You're welcome. Here are four of the five Brewsters. A three view of the 33E was not in the file.

 

[hesham]

Thank you Tailspin,


are there anythings about NAF Type A and Type B ?.

 

[Stargazer]

Please also see the following topic for the Boeing Model 368, a design that was a likely intermediary stage between Models 352 and 374:
http://www.secretprojects.co.uk/forum/index.php/topic,17481.0

 

[Tailspin Turtle]

The drawing for the NAF B was missing from the file

 

[hesham]

Excellent Tailspin,


the first time in my life to see a NAF project,and if there is a drawing to
Bell Model 22 proposal,that's great.

 

[Tailspin Turtle]

Bell 22

 

[hesham]

It's my lucky day,thank you very much Tailspin,


and finally,if you have a drawings to Boeing Model-352,McDonnell Model-7 & Model-8
and Vultee 79C,I am very grateful to you.

 

[Stargazer]

Tommy, this is fantastic, I'm really grateful to you.

Thanks to the Bell Model 22 plan, we now know the number of the Navy's specification: SD-112!

 

[Tailspin Turtle]

It's my lucky day,thank you very much Tailspin,and finally,if you have a drawings to Boeing Model-352,McDonnell Model-7 & Model-8
and Vultee 79C,I am very grateful to you.

I'm not sure why the file included a three view of the Vultee 79A since it isn't listed in the summary.

 

[lark]

The Early Aircraft Projects Department
is alive and kicking...
Thanks so much gents !

 

[hesham]

I can't believe,I am in a nice dream,


thank you Tailspin,you made my day.

 

[Stargazer]

Here are the enhanced three-view arrangements of the McDonnell Models 6, 7 and 8.

So after all the so-called "Bat"/"Manta" design was not one of these, but thanks to the great work of people like Tommy, I'm sure we'll eventually identify it...

 

[Tailspin Turtle]

It turned out that there was an NAF B in the file but I took a picture of it instead of scanning it. I took out some of the keystoning but I might have changed the relationship between the height and the width of the original in the process.

 

[klaud3]

Really great pictures!
Btw - do we know anything about arrester devices on Midway class at the time of the contest - maybe something non-traditional was planned? Vultee design (and possibly McD) shows that coupling traditional hook with pusher prop leads to pretty clumsy design, but I cannot imagine anything better for that layout... Could that be, that this requirement for the hook was initially not there, and only adding it later on threw all the pushers / pull-pushers out of the game?

 

[sienar]

It turned out that there was an NAF B in the file but I took a picture of it instead of scanning it. I took out some of the keystoning but I might have changed the relationship between the height and the width of the original in the process.

Could you post the original unaltered photo?

 

[hesham]

Very great work,well done Tailspin.

 

[Tailspin Turtle]

It turned out that there was an NAF B in the file but I took a picture of it instead of scanning it. I took out some of the keystoning but I might have changed the relationship between the height and the width of the original in the process.

Could you post the original unaltered photo?

The side view of my correction is slightly longer than the fuselage length on the top view. I didn't checked for overall squareness but it looks about right. If you come up with a better correction, please post it.

 

[Orionblamblam]

Here's my ten-second take on straightening it. Fixing the geometry of photographed drawings is easy; evening out the tone over the surface of the drawing is labor intensive, and I'm just too lazy.

 

[Tailspin Turtle]

Here's my ten-second take on straightening it. Fixing the geometry of photographed drawings is easy; evening out the tone over the surface of the drawing is labor intensive, and I'm just too lazy.

You got the side view length the same as the top view length so it's a better correction than mine. Thanks.

 

[famvburg]

Thanks for all of these, but I have a question. Were these single engine designs actually submitted for a twin engine proposal? I would think if the USN requested twin engine proposals the single engine stuff would be thrown right out. What's the scoop?

 

[Tailspin Turtle]

The number of engines was not specified. The strawman was a single-engine airplane, the F4U Corsair. Not only that, but liquid-cooled engines were not discouraged.

 

[Sundog]

Isn't the Manta shown on the first page the Davis Manta?

 

[lark]

Please take a look in the - Davis Manta - thread Sundog
and you will find answer perhaps..

 

[Antonio]

Time to choose a better name for the topic

 

[Steve Pace]

The USAAF was very interested in the Tigercat - XP-65. -SP

 

[Tailspin Turtle]

The USAAF was very interested in the Tigercat - XP-65. -SP

It was briefly a "joint" program but the Navy and Army requirements were incompatible and the Army withdrew.

 

[Tailspin Turtle]

A synopsis based on my research in the Grumman archives:

Grumman won an early 1941 Navy fighter competition with a twin-engine proposal, the G-51. Grumman was successful in establishing a joint Navy/Army program to develop it as the F7F for the Navy and the P-65 for the Army. On 30 June 1941, Grumman received a contract for two XF7F-1s to be powered by Wright R-2600 engines, which were subsequently changed to P&W R-2800 engines.

As often happened in these instances, the Army and Navy specifications differed in detail, with the Army requiring a pressurized cockpit, turbo supercharger, bigger tires, fuel system changes, and different armament. The Navy was unwilling to compromise and the Army cancelled the P-65 in January 1942 before Grumman had made much progress on detail design.