Grumman F7F very early model pics?

[frank]

Stumbled upon these pics on eBay. I'm posting a link to only 1 of 5 auctions showing various views. Tho I'm an F7F fan, I've never seen this design before. Very early design? The F7F relative, XP-65?

http://cgi.ebay.com/US-Navy-Grumman-F7F-Tigercat-4x6-B-W-photo_W0QQitemZ280380103243QQcmdZViewItemQQptZUK_Collectables_Aeronautica_MJ?hash=item4147f4da4b&_trksid=p3911.c0.m14

 

[Antonio]

looks XP-65 to me

 

[Stargazer2006]

I thought so too, but the seller states that these are photos from the U.S. Navy.
A mistake on her part? Also, wasn't the XP-65 a later design to the F7F? This looks older.

 

[Apophenia]

... wasn't the XP-65 a later design to the F7F?

The XP-65 and XF7F-1 were developed concurrently. Both were Grumman G-51s.

As to the identity of the model (and acknowledging that it's a photo of a model) . I'm wondering if there may be a clue in the markings.

Asymmetrical wing markings, fuselage cockade, and absense of tail stripes all suggest Army Air Corps sometime after the ACB's July 1940 markings memorandum. On the other hand, photos of F4F-3s in early 1941 show asymmetrical wing markings while later images of F4F-4s show symmetrical cockades. Both Wildcat variants show fuselage cockades and full tail stripes.

Does anyone know when the USN adopted asymetrical wing markings or exactly when the Navy got rid of the red tail stripes?

 

[Hoo-2b-2day]

It would appear to be an early design study for what eventually became the G-51 (F7F) series and could be within the G-46 (XP-65) or G-49 (Proposed export fighter with two R-2600 engines)series. Note that the engines are mid-mounted on the wind of the model, while both the G-46 and G-51 the engines were underslung on the wings.

 

[Stargazer2006]

The XP-65 was indeed the G-46 and therefore it seems only logical that it was developed a little before the F7F, not after as I stated before. Thanks for reminding us!

 

[Apophenia]

And the correction Hoo'!

 

[Tailspin Turtle]

I copied this off the interweb but don't know where:
Grumman Design 51

Grumman submitted its proposal for Design #51 to the U.S. Navy on 24 March 1941 to meet the
sea service's longstanding desire for a twin-engine carrier fighter. That June the Navy
awarded a contract for two prototypes. With Grumman giving priority to development and
production of the F6F Hellcat, work on the new fighter was slow and the first official flight
did not occur until November 1943. Eventually the Navy procured 364 production versions of
the fighter, which was called the F7F Tigercat, including photoreconnaissance and night
fighter versions. They served primarily with the Marine Corps and saw combat in Korea.

Probably the same place I got the pictures...

 

[Stargazer2006]

Same pics, and another source that gives this as the Model G-51 and a proposal for Navy...
Could we have a 3-view of the XP-65 proposal for comparison?
(don't know anything about G-69, so if that exists in planform too, why not?)

 

[Tailspin Turtle]

Same pics, and another source that gives this as the Model G-51 and a proposal for Navy...
Could we have a 3-view of the XP-65 proposal for comparison?
(don't know anything about G-69, so if that exists in planform too, why not?)

According to Corky Meyer's F7F monograph for Steve Ginter, Grumman proposed basically the same airplane—Design 51— to the Army Air Corps and the Navy, the former in January 1941 and the latter in March. The Army bought it as the XP-65 with a pressurized cockpit, and two 37 mm cannon in June but then canceled the procurement in January 1942. The Navy's version was unpressurized with four 20 mm cannon and four .50 caliber machine guns and ordered in May 1941 (Francillon states late June) as the XF7F.

Grumman had been trying to interest the Army in a follow-on to its XP-50 (design 46 and a derivative of the XF5F). This resulted in the Design 49, with two each of Wright R-2600 engines, 20 mm cannons, and .50 caliber machine guns.

Update: According to Baugher, the XP-65 engines were to be turbo supercharged and the XF7F engines, mechanically supercharged and the XP-65 was to also have four .50 caliber machine guns. There is a three-view drawing of the XP-65 in Meyer's monograph (also labeled Model G-45 which was the XP-50) which appears to be identical to the XF7F except for the windscreen.

The model pictured above may be the Design 49 or for the XP-65 proposal.

I'll try to remember to look into this the next time I visit Grumman...

 

[Apophenia]

Great stuff TT! These photos of the model make clear that the wing arrangement (and nacelle position) are much closer to the XF5F/XP-50 than the final XF7F.

 

[Stargazer2006]

To summarize the various aircraft described in this page, we have:

G-34 = U.S. Navy XF5F-1 "Skyrocket"
G-41 = U.S. Army XP-50 "Skyrocket" (sometimes found as the "Tomcat")
G-46 = U.S. Army XP-65 ("Tigercat")
G-51 = U.S. Navy XF7F-1 "Tigercat"

The scale model aircraft that is depicted above is apparently an early portrayal of G-46, perhaps presented by Grumman to the Navy when the replacement of the crashed XP-50 was in order.

Here are two 3-view drawings of the XP-50 and XP-65 taken from Model Designation Army Aircraft, Twelfth edition (Report number TSEST-A7), published by Chief of Engineering Division, June 1946. In that official USAAF document, the former is clearly named as "Skyrocket", while the latter has no name.

 

[joncarrfarrelly]

According to Grumman Aircraft since 1929 by Francillon, the XP-65 and F7F-1 were both Design 51, which was a single design that incorporated most features of Designs 46 and 49.

page 223: "Grumman's efforts were soon rewarded; the Army Air Forces ordered two XP-65 prototypes on 16 June, 1941,
and, two weeks later, the Navy awarded a contract for two F7F-1 prototypes. Sunsequently, however, both Services
concluded that a single design would not meet their specific requirements, and on 16 January, 1942, the Army dropped
out of the program to enable Grumman to optimize the design to satisfy naval requirements for twin-engined fighters
intended to operate from soon-to-be-ordered 45,000 ton Midway-class carriers and from land bases. Changes made
during the ensuing months were incorporated in the mock-up, which passed inspection in September 1942, and included
a switch from mid-mounted to shoulder-mounted wings."

Jon

 

[Stargazer2006]

If it were so, then the scale model would probably be G-46, right?

I don't know what to make of these authors writing contradicting information. Some of them have to be wrong! Francillon is usually reliable, though... Thanks anyway.

 

[Jos Heyman]

In my experience it is very common that the 'classic' books by Rene Francillon and others of the same respectable caliber, have minor inaccuracies as, since they did their research, a lot of new information has come to light. You will agree that this is especially as the internet and forums like this, allow the sharing of information, including the June 1946 source that has been mentioned. Since the 1946 source pre-dates Rene Francillon work and seems to be an authentic source, we have therefore discovered and matched another piece of history. So I would agree, XP-65 = G-46.
But are we 100% clear that the model represents the G-46?

 

[Stargazer2006]

The June 1946 source does NOT indicate G-46 as the Model number... It says this: "Aircraft was to replace the XP-50 and was similar to Navy XF7F model. Project cancelled." The diagram I reproduced above was next to the text. We'd have to see the dates of the contracts and documents binding the USAAC and Grumman to see which predates which... If the XP-65 predated the F7F by a few weeks/months, chances are they are not quite the same model... but if XP-65 was indeed "similar to" the F7F, and fashioned after it, chances are they are just two instances of G-51. The statement that XP-65 and XF7F-1 incorporated the most favorable features of the previous G-46 and G-49 designs now makes me lean in this direction... We have to investigate further...

And as for mistakes and inconsistencies in supposedly authoritative, talk to me about it! Alain Pelletier committed a series of Minidocavia books on USAAC types, and they are literally ripe with mistakes and typos! I even made a long list once that I set out to send to him, but I dare not...

 

[joncarrfarrelly]

In my experience it is very common that the 'classic' books by Rene Francillon and others of the same respectable caliber, have minor inaccuracies as, since they did their research, a lot of new information has come to light. You will agree that this is especially as the internet and forums like this, allow the sharing of information, including the June 1946 source that has been mentioned. Since the 1946 source pre-dates Rene Francillon work and seems to be an authentic source, we have therefore discovered and matched another piece of history. So I would agree, XP-65 = G-46.
But are we 100% clear that the model represents the G-46?

Francillon worked directly from Grumman records at the Grumman History Center in Bethpage and the book was published in 1989,
which was not very long ago.

 

[joncarrfarrelly]

Personally I'm leaning towards the model being the G-46/49 due to its fitting the description of an enlarged R-2600 powered aircraft
similar to the XP-50.

Now based on other info in Francillon, preliminary Grumman estimates for an aircraft designated XP-65 that is slightly larger than the Design 51 XP-65/F7F-1, it is possible that the design in the photos could have received a preliminary designation of XP-65. This is not without precedent in the numbering of USAAC/AF projects vis. the P-47.

As I quoted from Francillon previously, the XP-65 order date was 16 June, 1941 and the F7F-1 was ordered two weeks later,
which would be 30 June, 1941.

Jon

 

[RyanCrierie]

Not sure where to post this. But while looking through naval aeronautical organizations for 30 JUNE 1944; I found this:

Was it actually considered at one point to "farm out" the F7F production to a secondary production line in the same way the F4F = FM, F8F = F3M, and TBF = TBM?

EDIT: While looking at a copy of

RECORDS OF THE BUREAU OF AERONAUTICS (RG 72)
CONFIDENTIAL GENERAL CORRESPONDENCE, 1922-44
Entry 67

I found a box labelled:

Box 1497: VFR1/F23 -- VFT1/F1-1

So... what was the FT-1? We need to find out!