Grumman Concept - VFAX?

[circle-5]

Here's a Grumman concept model with no reference on the base. I'm guessing VAX or more likely VFAX, though it's a single-seater. Any documentation would be appreciated.

 

[Pioneer]

Here's a Grumman concept model with no reference on the base. I'm guessing VAX or more likely VFAX, though it's a single-seater. Any documentation would be appreciated.

Very nice!!
And very compact for a VG-wing design
I wonder if Boeing's TFX design had an influence on the over fuselage intake arrangement??

Any chance of more pics from different directions???

Regards
Pioneer

 

[circle-5]

Any chance of more pics from different directions???

Here's one more, with wings swept back.

 

[Triton]

Thanks circle-5!

 

[blackstar]

One wonders if they did any wind tunnel tests of that design at all. It looks like even a modest angle of attack would block airflow into the engines and cause an engine stall.

 

[elmayerle]

One wonders if they did any wind tunnel tests of that design at all. It looks like even a modest angle of attack would block airflow into the engines and cause an engine stall.

I don't know, there were some Northrop wind-tunnel studies that appeared in Journal fo Aircraft showing that proper intorduction of vortices made such inlets quite practical at high AoA. These appeared in the late-70's/early-80's time frame.

 

[blackstar]

Well, the B-2 has inlets that are far back above the wing like that, so it makes sense that Northrop was looking at the issue. Still, a fighter does a lot more high-AOA maneuvering, and that just looks like a bad idea on a fighter.

 

[elmayerle]

The wind tunnel studies reported on in those AIAA paers were clearly of fighter aircraft. I do know that at least one configuration in Northrop's ATF studies usde data from those tests.

 

[blackstar]

The wind tunnel studies reported on in those AIAA paers were clearly of fighter aircraft. I do know that at least one configuration in Northrop's ATF studies usde data from those tests.

Okay. Thanks. I'd only add that in the past thirty years, we haven't seen any fighter aircraft designed that way, even though it seems like putting the inlets above the wing would be good from a stealth standpoint.

 

[Sundog]

Okay. Thanks. I'd only add that in the past thirty years, we haven't seen any fighter aircraft designed that way, even though it seems like putting the inlets above the wing would be good from a stealth standpoint.

An early design study for the Gripen had a dorsal inlet, but once again, SAAB most likely didn't think it was worth the risk
It's the SAAB P.2107 design study.

As for the design in question above to meet the VFAX requirement, I think it most likely would have been fine. It wasn't going to hit alpha as high as our modern fighters do, and the highly swept glove in front of the inlet would have caused the creation of vortices, as on most strakes, which actually serve to re-energize the flow heading toward the inlet as alpha increased. Where these inlets would tend to get in trouble would be in sideslip conditions where the inlet could possible ingest part of that vortex. It might have been fine, it might not have been fine. I don't know. But the designers probably took that into consideration and decided that at the moderate sideslip angles this aircraft was likely to encounter, it wouldn't have been a problem.

 

[overscan (PaulMM)]

Here's a Grumman concept model with no reference on the base. I'm guessing VAX or more likely VFAX, though it's a single-seater. Any documentation would be appreciated.

Observations - it is small, essentially a scaled down TFX. Single seat. The top mounted intakes are F-111 style, putting them on top of the wing appears to have been done to free up the belly for a significant bombload. Clearly primary mission is attack.

These features make me think 1962 VAX (supersonic A-4 replacement) not VFAX. Just my thoughts.

 

[allysonca]

This was a wood Grumman model in my collection that was unmarked. Any ideas as to design number.

 

[overscan (PaulMM)]

Allyson - we already have a topic for this Grumman design but have not yet reached a conclusion on designation or even requirement. Do you have any information like date of manufacture?

 

[Manuducati]

From https://www.chadslattery.com/X-Plane-Models/132

Identified as Grumman Model G-310 VFAX factory model.

 

[dan_inbox]

Identified as Grumman Model G-310 VFAX factory model.

Surprising.
AFAIK the G-310 was the TFX/F-111.
And this model carries USAF tags, not Navy. Something doesn't add up IMO.

 

[Manuducati]

Identified as Grumman Model G-310 VFAX factory model.

Surprising.
AFAIK the G-310 was the TFX/F-111.
And this model carries USAF tags, not Navy. Something doesn't add up IMO.

That's how the model owner refers to it, not my identification.

As far as the TFX/F-111 is concerned, correct Grumman designation should be G-273 as explained here: https://www.secretprojects.co.uk/threads/grumman-project-list.568/post-93242

Maybe a Grumman proposition in case the USAF rejected the F-111 as well?

 

[overscan (PaulMM)]

VFAX covers the combined strike and fighter studies which predated the VFX F-14 (1966-67ish?) or the 1974-75 competition for a naval fighter which led to the F-18. Can't see it being the latter unless it was a strawman design to sell F-14s.

Other VFAX designs were presented to the USAF as well for the early "tactical fighter" stages of FX - McDonnell-Douglas Model 199 studies were done to VFAX as well as FX for example. So it could conceivably by a G-310 as proposed to VFAX, in a USAF version.

We could always ask Chad how it was identified.

 

[aeropix]

Chad here. Late to the party here, sorry. I ID'd this model based on the photos from a folder John Aldaz labeled < Grumman G-310 VFAX >. John was a stickler for accuracy. So though none of the photos show a positive nameplate or illustration labeled as G-310, I have to assume he ID'd it correctly somehow.