XTBF-1 wind tunnel model?

[Apophenia]

"Testing a 1/12th-scale model in the 12 Foot Free-Flight Tunnel, 1940."

http://history.nasa.gov/SP-4305/app-d.htm SP-4305 ENGINEER IN CHARGE Appendix D Facilities

When I first looked at these rather poor images, I thought the model was a SB2A. But the Brewster had an unkinked wing and flaps. This aircraft has flaps more like an Avenger. But the wingtips are rounded. The tailplanes are also rounded and the horizontal tails low set.

I'm not familiar with the early stages of the Model G-40 Avenger? Does anyone know if the first XTBF-1 had tail surfaces more like the Model G-18/XF4F-2 Wildcat prototype? Or did the prototype Avenger have square-cut surfaces like the second Grumman XTBF-1?

There's not much to go by in these wind tunnel photos. The canopy shape looks wrong for either the SB2A or the XSBA-1 (at Langley, Feb. 1939). I've retouched a photo of an Avenger scale model at roughly the same angle. It appears to match.

 

[Hoo-2b-2day]

It may be the Douglas VTB proposal of 1939 which was a competetive proposal to the Grumman TBF.

The Douglas design did have a more rounded fin with "squarish" wings.It also included a tricycle undercarriage which was it's downfall as the USN was not yet ready for this feature.

Ref:McDonnell Douglas Aircraft since 1920 Vol 1, R Francillon.

 

[Apophenia]

That's an interesting supposition, Hoo'. I hadn't thought of the other candidates for the 1939 VTB competition which would do more than just replace the Devastators.

Maybe Jon Carr Farrelly could post his 3-view of the Douglas VTB proposal here?
http://www.whatifmodelers.com/index.php/topic,17162.0/

Descriptions suggest an enlarged, R-2600-powered TBD-1. I guess that wind tunnel model could be any of the 18-odd submissions. Makes sense that those designs would resemble each other -- the XTB-1 and Vought XTBU-1 are essentially similar in layout.

It'd be nice to know more on the other 1939 VTB submissions. The Vultee V-57 (TBV) was a navalized V-85/A-31 Vengence. I'm guessing that Brewster submitted a navalized SB2A (after all, the SB2C-1 was later tested for torpedo launching ... why not the Buccaneer). But it seems that the makers were submitting more than one design.

And somewhere I saw mention of Hall Aluminum being involved as well. I wouldn't be surprised if Martin and Kaiser-Fleetwings were also in.

 

[Tailspin Turtle]

Hmm - It's hard to tell where the nose gear would have gone if there's a torpedo bay unless it was a very unusual retraction arrangement. The tail bumper does seem consistent with a nose gear. Both the BTD (XBTD-2 shown) and the TB2D had nose gears, so it's clear that it was a configuration they were pursuing...

 

[Apophenia]

Excellent stuff, thanks Tommy!

So, we can eliminate Douglas' VTB Proposal as being the wind tunnel model.

The VTB tricycle nose gear is indeed a puzzle. The XTB2D-1 got around it by mounting torpedos off-centre on the wing racks. Clearly, Douglas' tubby VTB proposal had an enclosed, central bay.

 

[hesham]

From Le Fana 442.