Republic AP-54, AP-55 fighters

[overscan (PaulMM)]

Republic AP-54, AP-55, from Aviation Week 5th December 1958, via Tony Buttler.

 

[elmayerle]

AP-54 is clearly derived from the radar-nosed version of the XP-91. Interestingly enough, the last time I saw the remaining one at the USAF Museum, it had the radar nose and the V-tail.

 

[Antonio]

Wow!!!...Today it's Republic's Day at Secretprojects ::

I have been looking for this models for a long time...but now I'm troubled. According to my sources AP-55 was suposed to be Republic's submission against Lockheed Starfighter and Northrop Fang. Am I wrong if I say that AP-55 in the photo doesn't looks very much as a Mach 2 fighter ???

 

[overscan (PaulMM)]

Its wings are highly swept, reminiscent of the F-105, which was Mach 2 capable, so I wouldn't discount the possibility.

 

[elmayerle]

AP-55 's inlets look very similar to the F-105A's inlets. I seem to remember that was a Mach 2 aircraft, so this that wouldn't be out of range for this one.

 

[Tophe]

Thanks for this post of the twin-boom AP-55 that I did not know...
Supersonic twin-boomers have not "existed" but many projects have been designed: a DH-110 derivative, a twin-fuselage in Tony Buttler's English Fighters book, the P.1216 candidate to what became the Typhoon II...

 

[Antonio]

Dear Friends, thanks a lot for the comments.
I'm not an engineer so it was not clear for me that this could be the tipycal shape for a Mach 2 interceptor: rounded nose and no area ruled fuselage...but Northrop's Fang had a similar nose and was a Mach 2 performer.

Please let me show a little comment:

I seem to remember that (F-105) was a Mach 2 aircraft

I thought the same of you, Evan and Paul, but according to "The American Fighter" by Angelucci & Bowers the Thud's max speed at 33,000 ft was 857 mph (1,379 Km/h) which it's below 1.5 Mach.


And the last question: what are this "things" in the wing tips of AP-54?. Too slim to be a fuel tank....

 

[Overkiller]

And the last question: what are this "things" in the wing tips of AP-54?. Too slim to be a fuel tank....



[/quote]

Anti flutter masses?

 

[overscan (PaulMM)]

Pometablava: thats definitely incorrect. An F-105B flew at Mach 2.15 during testing, according to "The Thunder Factory".

 

[Skybolt]

I thought the same of you, Evan and Paul, but according to "The American Fighter" by Angelucci & Bowers the Thud's max speed at 33,000 ft was 857 mph (1,379 Km/h) which it's below 1.5 Mach.

Probably with external loads/tanks? ???

 

[raravia]

Wow!...I´m spechless

Raravia

 

[Antonio]

Pometablava: thats definitely incorrect. An F-105B flew at Mach 2.15 during testing, according to "The Thunder Factory".

Thanks a lot for the info, Paul , and very bad for Angeluzzi/Bowers book because it is a very big mistake

 

[elmayerle]

I thought the same of you, Evan and Paul, but according to "The American Fighter" by Angelucci & Bowers the Thud's max speed at 33,000 ft was 857 mph (1,379 Km/h) which it's below 1.5 Mach.

Probably with external loads/tanks? ???

I'd hazard a guess that it's with maximum external loads/tanks, but in regard to weight and to drag. From what I've read, the F-105 was one of only two aircraft capable of supersonic performance "on the deck", the other was the A/RA-5.

 

[Steve Pace]

The "things" on the wings of AP-54 were to be attachment points for a canceled parasite fighter program.

 

[Stargazer]

A small pic, but it is worth adding here for the sake of completion.

 

[Steve Pace]

I recently found this desktop model image of the Republic AP-55 online. Enjoy! -SP

 

[Stargazer]

I recently found this desktop model image of the Republic AP-55 online. Enjoy! -SP

Brilliant!!! Such a cool design... Thanks a lot for this.

 

[Jemiba]

I second Skyblazer !
The model here http://www.secretprojects.co.uk/forum/index.php/topic,648.msg4880.html#msg4880
seems to show a single seat variant, but this one could well be a two seater, I think. The radom
seems to be bigger, too.

 

[Steve Pace]

Now if only we could find a good AP-54 image... -SP

 

[Steve Pace]

Look at pg 13 in this pdf

 

[lark]

There are two crisp color illustrations -aircraft model photo- about
both the AP-54 and AP-55 in:

Secret U.S.Proposals of the Cold War - Jim Keeshen.
(p.109 & .p.113)

 

[ivran]

Does somebody have a 3 view of AP-54 and AP.55 interesning design

 

[ivran]

Still try to found any new information about this lovely airplane projects, 3 view, pictures or dimensions, AP-54, is very close with F-105, but AP-55, is unknown project,
Great regards for all members

 

[StraGen410]

AP-55 's inlets look very similar to the F-105A's inlets. I seem to remember that was a Mach 2 aircraft, so this that wouldn't be out of range for this one.

AP-54 design might make sense to me. But can anyone explain me the AP-55 tail design? It gave a lot of questions about the reason for designer's choice of this strange twin broom tail. It looks pretty unstable to me and bring a lot of concerns that the tail might break apart itself if travelling at Mach 2 speed. The plane might be in a disadvantage situation if tthe enemy plane damaged it tail.

 

[riggerrob]

All airplanes are at a disadvantage after the enemy shoots off their tails!
Hah!
Hah!

Seriously, inverted V-tails have some handling advantages at lower airspeeds. For example, I was just looking at an American Eaglet light sailplane over on www.homebuiltairplanes.com. Eaglet's pilot sits in a teardrop pod and a single boom extends back to the inverted-V tail. In steep turns (e.g. spiraling in a thermal) most light planes need a bit of inside rudder and some up elevator. Inverted-V tails naturally combine those two control inputs.

 

[Jason Dykstra (Wyvern)]

Can this project trace its ancestry back to the F-84 and F-84F (XF-91 to a stretch)? Does it eventually lead to the F-105?