Grumman D-71/G-71

[KJ_Lesnick]

Actually, the design had no external tanks but a main tank and auxiliary tank

[KJ_Lesnick]

Good looking, similar to a P-80, and much better looking than a few of the early US navy jets.

It wasn't as fast as the P-80 unfortunately... still it's a spiffy design

[Captain Canada]

Cool !

[ennobee]

Looks to me like a F9F panther version with a coaxial jet engine instead of a centrifugal one, and with the tailplanes of a bearcat. I wonder if in an eventually production version the tail would look more triangular?

[KJ_Lesnick]

You know, an interesting note: This design could potentially produce a lead-on swept-wing version.

• If this design was developed, it would have likely flown in 1946 (The request came in 1944, and the FJ, F6U, and so on flew in 1946)
  
• The projected performance was pretty good compared to the FH-1 (though projected and actual isn't the same) at altitude (though it was less than the F2H)
  
• It still would have probably found itself obsolescent, and much like how the FD/FH lead to the F2D/F2H; this design could have been a similar concept
  
• If this version was at all like the pattern for the FH -> F2H, two years would pass, producing a design that would fly in 1948
  
• If swept wings were incorporated, transonic performance could be achieved: With an engine such as the J35 or J47; the design could actually potentially be more powerful even if it got larger (10,000 to 16,000)
  
• It would be a hell of a lot better than the F7U
  

.

Librarian

New to me too. I'd venture that being a Grumman product it would probably have done what it says on the box.

Well, according to what American Secret Projects: Fighters & Interceptors says, the designs projected performance was as follows

• Sea-Level Top Speed: 533 mph / 463 kts / Mach 0.7
  
• Top Speed Above 10,000 feet: 535 mph / 465 kts; this is a little short of mach 0.73 at 10,000 feet; a little over mach 0.74 at 15,000 feet; a between mach 0.75 and 0.76 at 20,000 feet; slightly over mach 0.77 at 25,000 feet, and provided mach limits didn't kick in to 30,000-35,000: This would provide a maximum level mach of just under mach 0.79 to about halfway between mach 0.80 to 0.81 (speculation)
  

I'm not sure how good they were at predicting jet performance in this era, and mach effects.  I'm curious what the FH Phantom's projected performance was (I know what it's actual was -- I want to compare)

[KJ_Lesnick]

Anybody have any T/C data on this thing?  The best I can do is basically use a ruler across an image which is a small image so errors result.  I got around 12.7% T/C