AF-86 Ground Attack Project

jackehammond

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Folks,

I remember in the early 1960s there was a project by North American for a cheap ground attack aircraft for our Asian allies which used the F-86 airframe where the engine was removed and replaced with armored fuel cells, the air inlet frames over with and propulsion was provided by two jet engines, with one slung under each wing. Anyone have any drawings of this project. I am looking through my pile of Flying Reviews hoping to find that drawing.

Jack E. Hammond
 
This reminded me no end of the Skyfox CT-133 rebuild. That was reinforced when I read the following:

"Canadair CL-76 -- Low-level tactical bomber. 1958. Used F-86 [CL-13] components. Two 2,900 lb (1,317 kg) st Pratt & Whitney JT-12s. Span 37 ft 1 in (11.3m); length 43 ft 7 in (13.28 m); height 14 ft 9 in (4.59 m)."

Source: p510 KM Molson & HA Taylor, Canadian Aircraft since 1909, Canada's Wings, 1982

Unfortunately, there is no image or further description.

Seeing the JT12 mentioned made me think of the Sabreliner. If this was a North American-insired design, would it not have been more logical to follow the Sabreliner layout (then on the drawing board) rather than redesigning the Sabre wing for engine mounts?
 
If this was a North American-insired design, would it not have been more logical to follow the Sabreliner layout (then on the drawing board) rather than redesigning the Sabre wing for engine mounts?
As I see it, mounting the new engines on the Sabre rear fuselage
1, moves the cg quite a way aft, meaning you either have to move the wing aft, or lengthen the nose, both involving major redesign,
2,means you have to get the tailplanes out of the way of the jet efflux, more redesign, and
3,You'll have to put in new structure to carry the engines anyway, again more design work.
So you might as well just redo the wing, which already has wet hardpoints incorporated...


cheers,
Robin.
 
Considering the timespan, I guess that the project might have been inspired by the German Me 262 somehow... (same configuration).
 
Don't forget if you're attaching two engines to the rear of the fuselage, you probably have removed the single engine that was back there so it should be that big of a CG shock. Look at the previously mentioned Skyfox. I think for the most part, adding two engines two the wings is not that hard. tWhile light airplanes, there are a number of single engine types that have been modded to twins, such as the Twin Navion and there is a twin-engined conversion to the old V - tail Bonanza that I can't recall the name of. As for as others, like some Beeches and Pipers, there isn't "that much" of a design change to go from single to twin configuration. ISTR there was a similar proposal for the F-84 as well and I think the drawings are here somewhere.

robunos said:
If this was a North American-insired design, would it not have been more logical to follow the Sabreliner layout (then on the drawing board) rather than redesigning the Sabre wing for engine mounts?
As I see it, mounting the new engines on the Sabre rear fuselage
1, moves the cg quite a way aft, meaning you either have to move the wing aft, or lengthen the nose, both involving major redesign,
2,means you have to get the tailplanes out of the way of the jet efflux, more redesign, and
3,You'll have to put in new structure to carry the engines anyway, again more design work.
So you might as well just redo the wing, which already has wet hardpoints incorporated...


cheers,
Robin.
 
Don't forget if you're attaching two engines to the rear of the fuselage, you probably have removed the single engine that was back there so it should be that big of a CG shock
Hmm, I dunno, look at the attached image below, the engine in the F-86 is mounted quite a way forward, and the rear fuselage is basically just a hollow fairing for the jetpipe.


Image source :- http://up-ship.com/blog/wp-content/uploads/2011/05/f-86-3.jpg found via Google Image search.


cheers,
Robin.
 

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Moonbat, this was stated by the OP :-
the engine was removed and replaced with armored fuel cells
Famvburg was stating that replacing the F-86's single engine with two new, rear fuselage mounted ones wouldn't alter the cg that much, as the existing engine was rear mounted. I was pointing out that the F-86's engine was, however, mounted quite far forward, hence there would be a large cg change...


cheers,
Robin.
 
While I think that Me-262/Meteor config is more plausible, I also think that Sabrliner's one is possible too: just think in Sabreliner itself which is similar size as AF-86.
 
ysi_maniac said:
While I think that Me-262/Meteor config is more plausible, I also think that Sabrliner's one is possible too: just think in Sabreliner itself which is similar size as AF-86.

I just came across this discussion, but this reminds me a bit of the Skyfox T-33 conversion http://en.wikipedia.org/wiki/Boeing_Skyfox as a possible analogy for a Sabreliner like configuration, also with respect to the CoG aspects.

Martin

P.S.: Oops - I saw Apophenia pointed that similarity out already, but at least now there's a link with pics.
 
Having two modern engine near the tail might not move the CG as far back as you might think. Two 2nd? 3rd ? generation engines might weigh only about 1/3 the weight of the J47 originally installed.
J47 = 2700 pounds per Wikipedia, JT12 = 430 pounds per engine from 1959 issue of Flight magazine on the web.
 
"Canadair CL-76 -- Low-level tactical bomber. 1958."

I would appriciate seeing a drawing or artist impression of this CL-76 design if anyone could ablidge me :)

Regards
Pioneer
 
Pioneer said:
I would appriciate seeing a drawing or artist impression of this CL-76 design if anyone could ablidge me :)

You're welcome, question still is the engine mounting. At the rear like the Sabreliner, or on/under the wings ?

This is a valid argument, I think :
Apophenia said:
...would it not have been more logical to follow the Sabreliner layout (then on the drawing board) rather than redesigning
the Sabre wing for engine mounts?

So I would use the middle fuselage, wings and cockpit section of the Sabre and a new nose and tail with engines.
But maybe there are more plausible propossitions.
 
Stargazer2006 said:
Wouldn't it have been easier to just start from the YF-93 variant?
No, not if you are starting with existing surplus F-86F airframes. And putting the engines under the wings would be a non-starter - you would lose existing external stores stations.
 
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