Beyond The Sprues
Modelling => Ideas & Inspiration => Aero-space => Topic started by: dy031101 on January 28, 2012, 07:12:41 AM
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P-39Q evolution with a motorjet and twin-boom in an attempt to raise the type's performance (Tophe did a version of it before at my behest).
(I was feeling lazy when I made this one, so no nose prop for now.)
(http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/Motorjet-P39.jpg)
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That could also be a turboprop.
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Or a pusher prop
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Oh wow, that is just...right.
Cheers,
Logan
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A couple I did a while back:
Conventional nose engine:
(http://i37.photobucket.com/albums/e68/GTwiner/More%20Creations/3712a18c.jpg)
Push/Pull:
(http://i37.photobucket.com/albums/e68/GTwiner/More%20Creations/e949a3a9.jpg)
Regards,
Greg
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Not quite P-39 or P-63 but definitely Bell-inspired ... these are part of an AltHist piece I'm working up. The gist is: what if Elsie MacGill had sold Canadian Car & Foundry brass and the RCAF on licenced Airacobras instead of Hurricanes for a new 'domestic' fighter in 1941?
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Interesting.
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Bell XFL-2 which would bear the same relationship to the P-63 that the XFL-1 did to the P-39.
A fully developed and "productionized" L-39-2, perhaps upgraded to a Merlin or Griffon for power.
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Diggin' the twin-boom P-39Q! (http://i107.photobucket.com/albums/m309/ChernayaAkula/Emoticons/377.gif) A design that surely warrants further studies in plastic! Soviet Lend-Lease with a 37mm or even N-45 45mm gun per boom for improved ground-attack qualities?
Reminds me a lot of the Saab J-15/21. Not that there's anything wrong with that. (http://i107.photobucket.com/albums/m309/ChernayaAkula/Emoticons/70.gif)
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Soviet Lend-Lease with a 37mm or even N-45 45mm gun per boom for improved ground-attack qualities?
37mm, maybe, but the 45mm is reputed to have massive recoil even with a muzzle brake, and therefore I'm a bit reluctant to have two of them......
My primary motive of cooking up this stuff, admittedly, is the question whether that motorjet is gonna help the twin-boom Airacobra at high altitude...... ;D
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Another option might be to look at scale-o-rama using a 1/48th scale P-39 or P-63 as your 1/72nd scale airframe. Of course there are going to be limitations on what can be achieved or considered practical but with the larger aircraft parts scaled down you would have room for a much larger engine in your fuselage. The upside is that your 45mm gun with massive recoil issues would now be controllable and you would have room for a second or third crew member depending on how you arrange things internally.
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Actually, the more I look at apophenia's CanCar Airabonita, the more I like it.
Title adjusted accordingly. :)
apophenia, your "new fighter" makes me wonder how far we can go in between- a "less-strategically-demanding" land-based Airabonita!
Also...... how big is the Vickers S compared to the Oldsmobile M4? And how possible would it have been that the Canadians would be inspired to copy the magazine design of the latter so more 40mm rounds could be carried, if Vickers S could indeed be mounted in the first place?
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Since the initial pic without the prop did stir up some other imaginations, I'm keeping that one at the top...
... and putting the definitive one with nose prop here.
(http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/Motorjet-P39_withNoseProp.jpg)
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Awesome, the P-39 is my favourite what if subject!
Alvis 3.1
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I always thought the P-39 was an interesting layout, and the more I read about it, the more I become convinced that it's lacklustre reputation is partly myth, partly bad luck and partly due to features other than the mid-mounted engine. Just a few things:
1. The mid-mounted engine forced a relatively long length or fuselage to be rigid, with some weight penalty. However Bell made this much worse by adopting the car-door layout, which denied them the use of the full fuselage depth for strength, thereby forcing the shallow "canoe" underneath it to be heavily reinforced.
2. Adding to the weight problem was the nosewheel, which brought with it a 300lb weight penalty and a number of unneccessary ground accidents when it collapsed. In this respect, the Airabonita is a more logical layout.
3. Much was made of the complicated control runs, but again, the car-door-layout prevented simpler solutions. With solid fuselage sides, the engine controls could have gone "straight back" instead of "forward a bit, down a bit, back a lot, up a bit".
My ideal mid-engined fighter would have the cockpit moved to the forward position (as in the Aircobra trainers), a decent-sized fuel tank between the cockpit and the engine, two synchronised cannons under the cockpit floor with ammo boxes behind it, and two more in the wing roots (FW-190 style) with ammo boxes in the wings.
P.S. - how odd: I've just been considering a scalorama'd 1/48th to 1/72nd Aircobra as the basis of an alternative FAA turboprop fighter to occupy the "slot" of the Wyvern in an alternative timeline....
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Or a pusher prop
This what you have in mind?
(http://i846.photobucket.com/albums/ab22/dy031101/PusherProp-P39.jpg)
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I think the P-39 did so well with the USSR since most of the air battle on the Eastern Front were at low to medium altitude. I wonder how it would have gone as a pure fighter on the Western Front if they had kept the turbo-supercharger of the original XP-39A.
(http://i37.photobucket.com/albums/e68/GTwiner/new%20one/XP-39s.jpg)
Regards,
Greg
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Bell's original conception:
(http://i729.photobucket.com/albums/ww291/joncarrfarrelly/MODEL3-01.jpg)
(http://i729.photobucket.com/albums/ww291/joncarrfarrelly/MODEL3-02.jpg)
Re: the turbo-supercharger, the problems were many and the original as-designed installation
was responsible for a number of the issues, including excessive drag. Realistically, the airframe
was too small to make effective use of the available turbos. However, a two-stage engine-driven
supercharger would have made a big difference rather than the standard Allison engine mounted
blower. The P-63 series used a two-speed/two-stage supercharger that was separate from the engine
and driven via a flex coupling.
Now whether having a better supercharger would have made the P-39 a better mid-to-high altitude
fighter is another issue, as you'd still have the relatively small and thick wing attached to an
aircraft that was intended more as a bomber interceptor than a pure fighter.
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Re: the turbo-supercharger, the problems were many and the original as-designed installation
was responsible for a number of the issues, including excessive drag.
I remember that someone suggested a Merlin-inspired supercharger but could no longer find that discussion or remember the details. :icon_crap:
EDIT: No turbocharger for Merlin, either, it seems. That's what fragmented memory does for ya.
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Actually, the more I look at apophenia's CanCar Airabonita, the more I like it.
Thanks dy! I think that the S gun would've been a non-starter for Canada. The Vickers didn't emerge until almost a year after the RCAF began formulating its 'domestic fighter' requirment. Besides, I doubt that the RCAF would've welcomed a new weapon that would need transport across the North Atlantic. After all, RW CCF-built Hurricanes were adapted to Packard engines and US machineguns, radios, etc.
BTW: the original winner of that RW contest was the Airacobra but it was dropped due to RCAF concerns about mechanical complexity and worries over potential speed of construction. Instead, home RCAF fighter squadrons received imported Kittyhawks and CCF Hurricanes and Sea Hurricanes surplus to overseas requirements.
In the AltHist scenario, CCF builds Canadianized Airacobras at Fort William and Hurricanes for overseas use in the East (components from their Turcot QC and Amhearst, NS plants assembled at an enlarged Dorval facility).
The Vidal components began as a reduction in strategic materials for the in-production CCF Cobra before being taken further in the front-engined design.
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Jon: Thanks for those Model 3 images! Attached is a real old-timer of mine -- boy I wish that I'd seen your drawings first! For starters, the canopy on the real concept was waaay nicer than mine. Oh well ... ;D
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By all accounts, the Kingcobra wasn't much better than the Airacobra, although the Russians used them quite happily in their theatre. I think the flaws that made the P-39 ordinary were more than just myth, to say nothing of the propellor's drive shaft sitting between the pilot's legs!
Regards,
John
I didn't say they were all myth, I said they were partly myth, partly bad luck and partly other factors that the mid-engined layout which is often blamed for all the Aircobra's woes.
Under "myth" I'm classing such "factors" as "the engine will squash the pilot in a crash" and "if the drive shaft comes loose it'll mince the pilot". My understanding is that there are NO recorded instances of either of these things actually happening.
Under "bad luck", I'd put the fact that US experience with the Aircobra started at a time when the average Japanese pilot was MUCH more experienced that the average American one, and the Aircobras in question were suffering from poor logistic support and maintenance. In other words, those squadrons would have had a thin time of it flying anything... The P-39 was then withdrawn from front line service and used predominantly for training in the States, which meant that a lot of even more inexperienced pilots got to fly them as their first high-performance mount and a quite a few died as a result. In other words, the P-39's reputation took the hit for the crashes that would have happened anyway, whatever aircraft the rookies were flying under that training regime.
"Other factors" are the car doors, the nosewheel and the missing turbo/supercharging, none of which were integral to the mid-engined layout.
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By all accounts, the Kingcobra wasn't much better than the Airacobra, although the Russians used them quite happily in their theatre.
The only reason why the US didn't take the P-63 is that they already had the P-51 (which was by then displacing every other fighter in the USAAF anyway)......
The Soviets, on the other hand, sure wouldn't mind a bigger P-39 with none of the Airacobra's weaknesses.
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Donny, the P-63 was inferior to the P-51 pure and simple. That's why it wasn't accepted into the USAAF inventory. To suggest otherwise is an insult to the capabilities of the Mustang.
I don't think he was trying to say that the P63 was superior to the P-51. What think what he was trying to say was that if the Mustang hadn't been available at all then the P-63 may well have been accepted into a greater frontline roll by the USA.
Speaking of which, that does bring some enticing possibilities - P-63s in the same shemes as worn by the various P-51 operated.
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According to both Birch Matthews' Cobra!: The Bell Aircraft Corporation 1934-1946 and
Pelletier's Bell Aircraft since 1935, the performance of the sole bubble-top, 1,425hp
V-1710-109 engined P-63D was roughly identical to that of the P-51D. So as the P-63D was no
improvement on the performance of the, all ready in mass production, P-51D, the USAAF
passed on ordering it in quantity.
This may be what Donny was thinking of.
An interesting unbuilt proposal was the XP-63B with 1,400hp Packard Merlin V-1650-5.
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Hmm..P-63D with RR Griffon engine and contra props... :icon_music:
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According to both Birch Matthews' Cobra!: The Bell Aircraft Corporation 1934-1946 and
Pelletier's Bell Aircraft since 1935, the performance of the sole bubble-top, 1,425hp
V-1710-109 engined P-63D was roughly identical to that of the P-51D. So as the P-63D was no
improvement on the performance of the, all ready in mass production, P-51D, the USAAF
passed on ordering it in quantity.
This may be what Donny was thinking of.
An interesting unbuilt proposal was the XP-63B with 1,400hp Packard Merlin V-1650-5.
The obvious thought that comes to mind is crossing the XP-61B and the P-63D.
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how about an Airacobra derived Soviet VTO. ...
http://www.unicraft.biz/on/kit1/kit1.htm (http://www.unicraft.biz/on/kit1/kit1.htm)
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Indeed P-63 at its best offers no improvement over the P-51. And no, what makes the Mustang shine (such as, first and foremost, range) isn't lost to me.
Floatplane fighter or racer derivatives?
(http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/daydreamerbis.jpg)
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Well there were real world racers...But not as snazzy looking as that one!
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Which all kind of makes the point: "only as good as a P-51" is hardly a condemnation given that the P-51 was such an exemplary machine. That means that if you didn't have P-51s, you'd be as well off with P-63s! The only reason the US didn't buy the P-63 in numbers was that they simply didn't need it, not because there was anything wrong with it.
Much the same could be said of the Martin-Baker MB.5, which was, by all accounts, a superb fighter, but there was no point complicating matters with another type when Tempests and Spitfires were pouring off the lines, the end of the war was in sight, and jets were just around the corner. Yet no-one tries to use the RAF's rejection of the MB.5 as "proof" that it was inferior in the way that some do with the P-63...
Anyway, Airacobra ideas. I have a few stashed away with the intention of doing some or all of these at some point:
1. Airacobra Autogiro. Cockpit moved forwards, pylon in original cockpit position with rotor that be clutched to the engine for start up. Clipped wings with gun pods on the ends.
2. Twin turboprop Aircobra. Co-axial, counter-rotating props, one small turbine in the nose bay, the other in the engine bay. Front engine has intake and exhaust on the same side, rear engine has them both on the opposite side: this is the only way to stop the rear intake from breathing the front engine's exhaust AND keep the exhaust thrust symetrical. Needless to say, the side doors are abandoned!
3. Scaleorama a 1/48th Airacobra to 1/72nd to make a big turboprop strike fighter that takes the same place in an alternative timeline that the Wyvern takes in the real one. This is part of a half-formed idea for Southsea Aircraft Ltd: a ficticious but hauntingly familiar company based in Dorset who's products included a high-winged STOL Army liason aircraft, a twin-engined single-seat fighter, a turboprop strike fighter for the Navy, and an awful lot of helicopters...
BTW, that floatplane P-63 is gorgeous! :-*
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Which all kind of makes the point: "only as good as a P-51" is hardly a condemnation given that the P-51 was such an exemplary machine. That means that if you didn't have P-51s, you'd be as well off with P-63s!
To be fair though, then the Allies would have needed something else to escort the Flying Fortresses all the way on bombing missions, to say the least (which might have hastened the advent of the P-47N?).
P-63 is still one of my favourite WWII fighters, nonetheless.
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(http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/p63d_longRange.jpg)
P-63D with new wings. So where did I take the wings from...... >:D
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([url]http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/p63d_longRange.jpg[/url])
P-63D with new wings. So where did I take the wings from...... >:D
A P-47N, obviously.
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Tempest?
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Weaver's #2 and #3 concepts in reply 29 are what I would like to see in Styrene. Cool stuff 8)
Bill
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Now whether having a better supercharger would have made the P-39 a better mid-to-high altitude
fighter is another issue, as you'd still have the relatively small and thick wing attached to an
aircraft that was intended more as a bomber interceptor than a pure fighter.
Does the XFL-1/2 use the kind of wing? Or is the Airabonita more of a general-purpose fighter?
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Does the XFL-1/2 use the kind of wing? Or is the Airabonita more of a general-purpose fighter?
Airabonita wing was essentially that of the P-39 with the main gear moved to the front spar and twin radiators replacing the Airacobra's buried rads.
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A P-47N, obviously.
elmayerle got it right. Although I was wondering if I was onto something......
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I want to do something to the XFL...... but don't know what to do.
In the end, just nose guns (don't know what apophenia puts in his, but mine is as the P-39Q; Wikipedia claims that production Airabonita can be so equipped), four-blade propeller, and elimination of arrestor hook (which apophenia also did with his). I didn't bother with wing gun pods because I also heard that many P-39Q pilots chose to get rid of those to save weight.
I assume a Merlin-inspired supercharger wouldn't be externally-visible?
(http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/Bell_Model17.jpg)
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Since the P-39 had a large wheel bay in the bottom of the nose, you've got to wonder what the Airabonita had there? I wonder if there was enough space for a third 0.50 cal MG?
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Since the P-39 had a large wheel bay in the bottom of the nose, you've got to wonder what the Airabonita had there? I wonder if there was enough space for a third 0.50 cal MG?
Good question. With some revision of that lower 'chassis' structure, I'm sure that you'd have room for that 0.50 in the centre and another pair on either side of the lower fuselage (P-51A-style).
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Airabonita wing had increased span, chord and dihedral; the fuselage was shortened; cockpit raised
and vertical tail surfaces revised in shape. It wasn't just a tail-dragger Airacobra.
;)
The 37mm gun was intended as main armament.
Vought won the "contest" with what became the Corsair.
The XP-39E was powered by the two-stage Allison V-1710-E9 (similar to the engine that powered the P-63)
and the fuselage was 20 inches longer. So, if when speaking of a 'Merlin-inspired' supercharger one means
the two-stage/two-speed type as equipped the Packard-Merlin V-1650, then yeah, it'll be visible as you
couldn't fit it into the P-39 airframe and retain a useful load, a stretch would be sensible. Yes, the Cobra I & II
air racers had P-63 engine shoe-horned into P-39 fuselages, however these aircraft were stripped to the bone,
and weight/balance issues that would be critical in a service aircraft, were just part of the fun.
A note on terminology, there was and is no 'Merlin' supercharger per se, the various engine driven centrifugal
superchargers used on R-R engines were based on what had become fairly standard supercharger design
principles that had been worked out by engineers and designers in several countries. BTW the French stuck with
a less efficient, and more complicated, home-grown design for the Hispano-Suiza engines after just about
everyone else had adopted simpler, cleaner designs.
Also Allison, if GM had been willing to spend the money to hire enough designers and pay the development cost,
could have come up with a better two-stage design than the one use don the P-63 and P-82 engines, Hell, they
could have adopted elements of Pratt & Whitney's two-stage designs that worked so well on their radials.
:icon_fsm:
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Great exploration of this type. I once toyed the idea of the Russians license copying the P-39 fuselage onto a Parabola wing with rudderlets at the tips, but built my Revell 144th cobra stock and standard like a wuss', -----made up some karma by building the car doors open and a instrument panel detail level that would rival a 1/48th kit. The original kit had a look-through from the cockpit down through the front gear doors!
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Since the P-39 had a large wheel bay in the bottom of the nose, you've got to wonder what the Airabonita had there? I wonder if there was enough space for a third 0.50 cal MG?
Good question. With some revision of that lower 'chassis' structure, I'm sure that you'd have room for that 0.50 in the centre and another pair on either side of the lower fuselage (P-51A-style).
Not sure about that: the P-39 was built around a very strong structural "keel box" that had to be full-width to keep the engine and gearbox aligned, so there was room for a full-width gun bay above it, but nothing to either side of it. The nosewheel bay was in the middle of it.
Good cutaway:
(http://www.fiddlersgreen.net/aircraft/Bell-P39-Airacobra/IMAGES/Bell-P-39-Airacobra-Cutaway.jpg)
From here: http://www.fiddlersgreen.net/aircraft/Bell-P39-Airacobra/IMAGES/Bell-P-39-Airacobra-Cutaway.jpg (http://www.fiddlersgreen.net/aircraft/Bell-P39-Airacobra/IMAGES/Bell-P-39-Airacobra-Cutaway.jpg)
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The XP-39E was powered by the two-stage Allison V-1710-E9 (similar to the engine that powered the P-63)
and the fuselage was 20 inches longer. So, if when speaking of a 'Merlin-inspired' supercharger one means
the two-stage/two-speed type as equipped the Packard-Merlin V-1650, then yeah, it'll be visible as you
couldn't fit it into the P-39 airframe and retain a useful load, a stretch would be sensible.
If I'm using XFL-1 as a base, would the new engine alone be enough to "make it good"?
IIRC, XP-39E was unsuccessful because other aerodynamic changes made it inferior at lower altitudes to stock P-39s.
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I wonder...a dedicated tank buster AP-39...ancestor of the A-10/competitor to the Il-2?
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If re-engining the XFL-1, why not go all in and make it an air-cooled version of the V-1710?
Air-cooled and inverted air-cooled versions were made of the Liberty engine, so why not the V-1710?
A compact two-speed/single-stage blower would probably give the required low to mid-altitude
performance required of a fleet air defense fighter.
:icon_fsm:
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If re-engining the XFL-1, why not go all in and make it an air-cooled version of the V-1710?
Because I don't know how to make visual representations thereof ;D
(http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/Bell_Model17E.jpg)
Land-based FL-1 with stretched fuselage to accommodate two-stage-supercharged V-1710.
Is "Model 15" already occupied within the Bell company designation?
(Wondering if I can use it as a what-if designation for a land-based XFL-1......)
EDIT: As per jcf's suggestion below, the pics are now named "Model17".
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Model 15 = P-39D
7,8,9 and 17 - 25 inclusive are not on the list in Pelletier's Bell Aircraft since 1935.
Now that I've said that, Stephane will probably be along with the missing numbers. ;D
Air-cooling means you need air-intakes and exhausts, so eliminate the radiator housings
under the wings and add some inlets and outlets on the fuselage, perhaps something
resembling the side-scoops of the XP-39.
The Piaggio P.119 had an air-cooled radial buried mid-fuselage, so perhaps look at it
for inspiration on your vents.
http://www.airwar.ru/enc/fww2/p119.html (http://www.airwar.ru/enc/fww2/p119.html)
(http://www.airwar.ru/image/idop/fww2/p119/p119-3.jpg)
:icon_fsm:
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If re-engining the XFL-1, why not go all in and make it an air-cooled version of the V-1710?
Air-cooled and inverted air-cooled versions were made of the Liberty engine, so why not the V-1710?
A compact two-speed/single-stage blower would probably give the required low to mid-altitude
performance required of a fleet air defense fighter.
The engine technology advances from the Liberty to the V1710 would make an air-cooled version of the V1710 much more difficult than air-cooled versions of the Liberty. With the engine buried like that, it would take some interesting cooling scoops, cooling air exhaust ducts, and engine baffling to properly cool an air-cooled engine.
dy, IMHO using a R2800 would yield just as portly an airframe as the Piaggio.
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dy, IMHO using a R2800 would yield just as portly an airframe as the Piaggio.
Might there have been a radial with a better balance of size and output for the "air-cooled" Airabonita? Or would the R-2800 have been perfectly good anyway?
Nevertheless, I tried an intellectual exercise with R-2800.
(http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/FL1_r2800.jpg)
What do you think?
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Hmm, I'd love to see the frontal view of that one. The profile definitely looks interesting.
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I did try to keep the nose and cockpit to the same scale as the engine when I pasted together the sideview, but the result might still look rather like the Piaggio P.119 (3-view here (http://www.aviastar.org/air/italy/piaggio_p-119.php)) frontally.
Actually that's where the chin intake idea (as suggested by jcf) comes from. The control surfaces of the XFL-1 were scaled up.
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Ah, I see. I wonder if a newer wing derived from that of the P-63 would help performance? For more fun, the wings and tail surfaces of the L39-2 but with retracting gear.
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Skip the R-2800 and use the 21-cylinder R-2300 Triple Wasp Jr.* ;)
It's 44" diameter would mean that the airframe would'nt be as porky.
Anyhow effectively cooling a buried radial is not any easier than cooling an air-cooled V-12,
and there is no reason that Lawrance type air-cooled cylinder design (the basis of all Wright and P&W
air-cooled radials) could not be successfully applied to the V-12 format. Wright built the air-cooled
V-1460 and V-1560 engines in the late-twenties and there is actually no technological reason that
development of high-powered air-cooled V engines couldn't have continued, if so desired.
:icon_fsm:
* of course such an engine never existed in the 'real-world', but when did that ever stop us? ;)
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An X or H engine would be a good compact choice too. Sabre-Cobra anyone?
Some of the Fairey designs that eventually lead to the Gannet had two Merlins, one behind the cockpit and one under it, driving co-axial counter-rotating props. It struck me that the design might be compact enough for a fighter (as opposed to an attack aircraft) if the engines were smaller capacity flat-12s, i.e. total engine power is about 2 x 1000 hp as per a conventional late-war fighter but you have the advantages of two engines, smaller prop diameter etc....
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(http://i846.photobucket.com/albums/ab22/dy031101/Parallel%20World%20and%20What-if/FL1_r2800_lateModel.jpg)
R-2800-powered FL-1 with P-63-derived wings and four-blade propeller.
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Anyhow effectively cooling a buried radial is not any easier than cooling an air-cooled V-12,
and there is no reason that Lawrance type air-cooled cylinder design (the basis of all Wright and P&W
air-cooled radials) could not be successfully applied to the V-12 format. Wright built the air-cooled
V-1460 and V-1560 engines in the late-twenties and there is actually no technological reason that
development of high-powered air-cooled V engines couldn't have continued, if so desired.
Well, actually, cooling a long row of cylinders gets to be a bit more of a chore than cooling a radial, especially when you get to the cylinders farthest from where the cooling air enters (one reason Lycoming's IO720 isn't/wasn't as popular as it might have been, that fourth row of two cylinders needed extra cooling scoops since air coming in the front of the cowling really wasn't reaching them, even with good baffling directing the flow). The same applies to multiple rows in a V or IV configuration.
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Anyhow effectively cooling a buried radial is not any easier than cooling an air-cooled V-12,
and there is no reason that Lawrance type air-cooled cylinder design (the basis of all Wright and P&W
air-cooled radials) could not be successfully applied to the V-12 format. Wright built the air-cooled
V-1460 and V-1560 engines in the late-twenties and there is actually no technological reason that
development of high-powered air-cooled V engines couldn't have continued, if so desired.
Well, actually, cooling a long row of cylinders gets to be a bit more of a chore than cooling a radial, especially when you get to the cylinders farthest from where the cooling air enters (one reason Lycoming's IO720 isn't/wasn't as popular as it might have been, that fourth row of two cylinders needed extra cooling scoops since air coming in the front of the cowling really wasn't reaching them, even with good baffling directing the flow). The same applies to multiple rows in a V or IV configuration.
Operative term is buried i.e. like the Piaggio P.119, and I'm quite familiar with the ins & outs of air-cooled
engines in their various permutations, in the real world. The Armstrong-Siddeley inline cylinder radials had
cooling problems, thus the big scoop arrangement on the Whitley testbed for the Deerhound. The air was
brought in behind the spinner and then ducted over the cylinder banks from the rear, exiting at the
forward end of the cowling.
The Gypsy-12 powered D.H. 91 and D.H.92 used a similar reverse-flow ram-air cooling system.
So as we are talking about fantasy aircraft, why not a buried air-cooled V-12 naval fighter with reverse-flow
ram-air cooling? No one has said it would have to be a successful design.
;)
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Actually, I'd probably use scoops feeding air in between the cylinders from both from and back, further pressuring that area and getting the cooling flow across the cylinder fins and out through exit louvers or flaps (I like louvers myself, but flaps might give you a smidgeon of thrust) on each side of the aircraft (at least that way you don't have hot air from both sides meeting in the middle, as reversing this concept would do, and going out, depending on V or IV configuration, louvers in the top or bottom of the fuselage). I can certainly see where they'd try it to get a more streamlined air-cooled fighter; how successful it would be is another question indeed.
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You could perhaps see an arrangment almost like a cetrifugal-jet-engined type, with a fan behind the prop forcing air through ducts around the cockpit to the engine, and then venting it through a long tube to the rear. Alternatively, the fan could sit on the front of the engine (as opposed to the gearbox), which would have the advantage of it running faster, sucking air in through wing-root intakes and blowing it out through wing-root exhausts, a bit like a Seahawk.
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I have a P-63 in bits in storage that I will complete someday as a R-2800 engined variant. It will have semi-annular air inlets on either side of the fuselage, putting the increased frontal area from the engine's bulge to good use. I had given thought to venting the now hot air at the aft end of the bulge, making it all something of a mid-mounted Townend Ring/NACA cowling!
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Random idea: thermojet P-39/P-63
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The more I think about it, the more I like the idea of a turboprop P-63. Engine still behind pilot and still driving prop via shaft. Could prove an interesting platform in the late '40s/early '50s.
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Greg, that would work very very well methinks.
With all the Lend-lease P-39s sent over and the general Soviet approval of the airframe, they continue to develop the aircraft a bit and export it, along with the MiG-15/17 to African and West Asian nations. Serves well into the 1980s with a few even arriving in South America. Never quite becomes a P-63.
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One of my coworkers at Bell is a modeller and looks to combine a P-63D with the wings of the L-39-2. That should look quite striking.
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With all the Lend-lease P-39s sent over and the general Soviet approval of the airframe, they continue to develop the aircraft a bit and export it, along with the MiG-15/17 to African and West Asian nations. Serves well into the 1980s with a few even arriving in South America. Never quite becomes a P-63.
I like the thinking. I would use the P-63 as the basis though.
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One of my coworkers at Bell is a modeller and looks to combine a P-63D with the wings of the L-39-2. That should look quite striking.
I've got two L-39-2's in the stash and was thinking something similar with the second kit Evan. Mind you the Fireball with Sabre wings will get done first ----
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The more I think about it, the more I like the idea of a turboprop P-63. Engine still behind pilot and still driving prop via shaft. Could prove an interesting platform in the late '40s/early '50s.
How about a ASM.3 Mamba? It's in the right timeframe and roughly the same dimensions as the V-1710. Of course, it only weights about half as much as the Allison. Good chance to push the powerplant rearward and sneak in a c/g fuselage fuel tank.
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How about a ASM.3 Mamba? It's in the right timeframe and roughly the same dimensions as the V-1710. Of course, it only weights about half as much as the Allison. Good chance to push the powerplant rearward and sneak in a c/g fuselage fuel tank.
You wouldn't be able to move it very much ap', mid-engined aircraft have the engine almost right on the cg point. It's the reason Rolls Royce started their 'Private Venture' fighter with a mid-engine, they reasoned that if they wanted to install another bigger, heavier, more powerful engine, they wouldn't have to do much changes to the airframe because the cg would still be in the same position.
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Good point kit'. Don't want to turn her into a tail-sitter!
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The more I think about it, the more I like the idea of a turboprop P-63. Engine still behind pilot and still driving prop via shaft. Could prove an interesting platform in the late '40s/early '50s.
Or there's this variation I thought of:
2. Twin turboprop Aircobra. Co-axial, counter-rotating props, one small turbine in the nose bay, the other in the engine bay. Front engine has intake and exhaust on the same side, rear engine has them both on the opposite side: this is the only way to stop the rear intake from breathing the front engine's exhaust AND keep the exhaust thrust symetrical. Needless to say, the side doors are abandoned!
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Turboprop P-63:
(http://i37.photobucket.com/albums/e68/GTwiner/More%20Creations/BellP-63KingcobraAJ-Press0068.jpg)
Maybe even as a counterpart to the Turboprop Mustang?
Note that I envisage this as having a reverse flow turbine akin to the PT6.
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P-51 is fine and gets much attention. Like seeing P-39/63 getting attention as a turboprop :)
Worthy of doing in plastic.
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Turboprop P-63:
Note that I envisage this as having a reverse flow turbine akin to the PT6.
Great idea, there's even a resin Wyvern exhaust replacement set available in 1/72 to do just that:
http://www.hannants.co.uk/product/QB72015 (http://www.hannants.co.uk/product/QB72015)
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http://alternathistory.org.ua/nesostoyavshiisya-naslednik-aerkobry-ili-alternativnyi-palubnyi-bombardirovshchik-torpedonosets-bell (http://alternathistory.org.ua/nesostoyavshiisya-naslednik-aerkobry-ili-alternativnyi-palubnyi-bombardirovshchik-torpedonosets-bell)
Is this one of Aircobra kin? Or could have been.
(http://alternathistory.org.ua/files/resize/ad/s-470%5B1%5D-700x656.jpg)
(http://alternathistory.org.ua/files/resize/ad/s-403%5B1%5D-700x629.jpg)
Just wondering.
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[url]http://alternathistory.org.ua/nesostoyavshiisya-naslednik-aerkobry-ili-alternativnyi-palubnyi-bombardirovshchik-torpedonosets-bell[/url] ([url]http://alternathistory.org.ua/nesostoyavshiisya-naslednik-aerkobry-ili-alternativnyi-palubnyi-bombardirovshchik-torpedonosets-bell[/url])
Is this one of Aircobra kin? Or could have been.
([url]http://alternathistory.org.ua/files/resize/ad/s-470%5B1%5D-700x656.jpg[/url])
([url]http://alternathistory.org.ua/files/resize/ad/s-403%5B1%5D-700x629.jpg[/url])
Just wondering.
Hmm, a turbo-prop version with a PT6T?
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Made up by the artist.
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Though admittedly attractive and certainly worth someone having a go at modelling. ;)
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Thanks for the feed-back.
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Does anyone know if you can get kits or conversions of the twin seat P-39/P-63...preferably in 1/48:
(http://mig3.sovietwarplanes.com/lendlease/tp-39/us8.jpg)
(http://mig3.sovietwarplanes.com/lendlease/tp-39/us7.jpg)
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Does anyone know if you can get kits or conversions of the twin seat P-39/P-63...preferably in 1/48:
([url]http://mig3.sovietwarplanes.com/lendlease/tp-39/us8.jpg[/url])
([url]http://mig3.sovietwarplanes.com/lendlease/tp-39/us7.jpg[/url])
there was a resin & vac conversion a few years ago .... not sure what scale or manufacturer.
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How about, as we are doing a Scalorama build, a 1/48 Airacobra done as a 1/72 attack bomber, torpedo bomber, or dive bomber?
Most of the naval types, Devastator, Dauntless, Avenger, Barracuda etc. were about 50% larger than the P-39. Using the Griffon, Sabre, Vulture or even some of the radial option suggested earlier in the topic for the required extra power, you could possibly also incorporate an internal bomb bay and maybe a 57mm Mollins gun in place of the 37mm Oldsmobile cannon. A bubble canopy or glass house and one, two or three crew. Maybe if its done as a tail dragger there could be a bomb aimers position in the nose.
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(https://ww2aircraft.net/forum/attachments/oi-2-jpg.304243/)
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(https://ww2aircraft.net/forum/attachments/1613246142379-png.612520/)
(https://ww2aircraft.net/forum/attachments/1613246178835-png.612522/)
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(https://ww2aircraft.net/forum/attachments/02f-jpg.381846/)
(https://ww2aircraft.net/forum/attachments/p-63-skis-jpg.353421/)
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Random ideas:
Mexican or Brazilian P-63s.
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I saw a pic of a P-39 with the front removed from the cockpit forward. All I could see was the start of an attack helicopter. Two cockpits stacked like a Hind. I’ll have to find a couple Monogram kits and see what happens.
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That RAF trials P-63 aircraft looks more than doable -----
And the Twin Cobra has peaked my interest too, maybe with King Cobra fins though, or even the extended P-63 fin that you can/could get from Obscureco (got one in the stash too)
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Carrier based anyone?
(http://www.forgottenprops.warbirdsresourcegroup.org/images/airacobra/p-39_airacobra_42-19490_WRG-000040164.jpg)
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I saw a pic of a P-39 with the front removed from the cockpit forward. All I could see was the start of an attack helicopter. Two cockpits stacked like a Hind. I’ll have to find a couple Monogram kits and see what happens.
The infamous TP-39 may be a useful guide. ;)
https://massimotessitori.altervista.org/sovietwarplanes/pages/lendlease/p-39/tp-39/twoseaterp-39.htm
(https://massimotessitori.altervista.org/sovietwarplanes/pages/lendlease/p-39/tp-39/tp39q.jpg)
(https://massimotessitori.altervista.org/sovietwarplanes/pages/lendlease/p-39/tp-39/us5.jpg)
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His Areocobra had a nosewheel normally attached. It wasn't a lashup.
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Does anyone know of a 1/48 P-63D kit or conversion?
(http://www.aviation-history.com/bell/p63d-25a.jpg)
(http://www.wunderwaffe.narod.ru/Magazine/AirWar/28/Draw/17.jpg)
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Does anyone know of a 1/48 P-63D kit or conversion?
The old MPM 1/48 P-63A/'C Kingcobra kit came with a P-63D canopy conversion (and a resin P-63F tail conversion set). The kit itself said to be rather poor ... but m aybe someone out there built an 'A, 'C, or 'Pinball', and chucked the canopy conversion into their spares box?
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Does anyone know of a 1/48 P-63D kit or conversion?
The old MPM 1/48 P-63A/'C Kingcobra kit came with a P-63D canopy conversion (and a resin P-63F tail conversion set). The kit itself said to be rather poor ... but m aybe someone out there built an 'A, 'C, or 'Pinball', and chucked the canopy conversion into their spares box?
These?
(https://www.scalemates.com/products/img/2/1/8/1220218-51927-40-1440.jpg)(https://www.scalemates.com/products/img/5/4/7/281547-13796-29-pristine.jpg)
I have the one with the RP-63A Pinball conversion bits in the stash but am not sure if it had the Bubble Canopy bits there as well.
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Does anyone know of a 1/48 P-63D kit or conversion?
([url]http://www.aviation-history.com/bell/p63d-25a.jpg[/url])
([url]http://www.wunderwaffe.narod.ru/Magazine/AirWar/28/Draw/17.jpg[/url])
I wonder about combining that with a retractable-gear version of the L-39-2.
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I have the one with the RP-63A Pinball conversion bits in the stash but am not sure if it had the Bubble Canopy bits there as well.
Ah, so it sounds like the conversion bits were offered either/or ... not both :(
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Off topic posts removed
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Fine Greg but I did actually have some on-topic content that managed to get lost in the noise. Let me try again.
Westinghouse J30 or J34 engined TurboCobra. Sort of a coming together of a P-63 and a McDonnell FH-1. Although on further thought, I'd model it with bits from an Airfix F2H for ease.
ETA: Of course that leads to thoughts of a mid-V-1710 engined McDonnell fighter in exchange....
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I've always wondered why they picked the P-63 for swept wing testing. I always thought they used the wrong aircraft. I've got a project of using the L-39 wings and attaching them to a Ryan Fireball. I'm putting a R-2800 on the front, stretching the fuselage some, and other things ---
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I've always wondered why they picked the P-63 for swept wing testing. I always thought they used the wrong aircraft. I've got a project of using the L-39 wings and attaching them to a Ryan Fireball. I'm putting a R-2800 on the front, stretching the fuselage some, and other things ---
Cool-sounding project :smiley: Your concept has powerplant similarities with Grumman's G-57 design study - 1 x R-2800 + 1 x Halford H.1 (later DH Goblin) turbojet.
The BuAer looked at a number of swept-winged research aircraft proposals. AFAIK, none of them came from Ryan. Grumman submitted two concepts - one a Wildcat with new swept wing panels; the second a completely new design (the G-77). [1] I'm rather surprised that the BuAer didn't choose the modified Wildcat - its retractable undercarriage would give the option of relatively high-speed wing testing as well.
That the BuAer didn't accept Grumman's F4F-based proposal suggests that their choice was based on available design staff time and shop floor space. Grumman was, of course, occupied with getting production Bearcats into service. Had Ryan actually submitted a swept-wing proposal, I suspect they'd have been told to focus on fixing the XFR-1's problems first - like making sure that the wings didn't fall off anymore!
Weirdly, the Bell Model 39 used modified P-63 outer wing components somehow rearranged into that swept form. The Kingcobra also had the advantage of having a really narrow centre section - maximizing how much swept span you got. By comparison, the FR-1 had a much wider centre section. That wouldn't stop you from applying sweep to the Ryan's outer wing panels but with a reduced swept span. Of course, your whif gets around that if you adopted the entire L-39 wings ;)
The Kingcobra fuselage break point also proved fortuitous when the L-39's tail moment arm was found wanting. The FR-1 had a similar construction break but any rear fuselage extension would be somewhat complicated by that break being linked to turbojet engine access. Again, with your whif, the R-2800 would balance c/g for any rear fuselage extensions required.
_______________________________
[1] The low-winged G-77 was to have ground-adjustable wing-sweep angle (kind of like the Messerschmitt P.1101 jet). It would have been powered by a modest 450 hp P&W R-985. I'm not sure about the model number of the swept-wing F4F proposal. Since the full-span flap Wildcat was the G-53, I'd guess that the swept-wing modified F4F proposal Model number was in the 54-to-57 range.
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The USN L-39 was used for low-speed handling research on swept wings, it wasn't about
exploring performance improvements. They had other projects in hand for that work.
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The USN L-39 was used for low-speed handling research on swept wings, it wasn't about
exploring performance improvements. They had other projects in hand for that work.
Yeah, I know that Jon, I was thinking along the lines of an 'in-service' derivative ----
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Weirdly, the Bell Model 39 used modified P-63 outer wing components somehow rearranged into that swept form. The Kingcobra also had the advantage of having a really narrow centre section - maximizing how much swept span you got. By comparison, the FR-1 had a much wider centre section. That wouldn't stop you from applying sweep to the Ryan's outer wing panels but with a reduced swept span. Of course, your whif gets around that if you adopted the entire L-39 wings ;)
The Kingcobra fuselage break point also proved fortuitous when the L-39's tail moment arm was found wanting. The FR-1 had a similar construction break but any rear fuselage extension would be somewhat complicated by that break being linked to turbojet engine access. Again, with your whif, the R-2800 would balance c/g for any rear fuselage extensions required.
Stephen, while matching up parts and comparing things on another project of mine, I found that if you angle back a P-51H wing, it has the same plan form and size as the swept wing F-86A wing. All it needed was the leading edge extended (towards the fuselage) or trailing edge extended (towards the wing tip).
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A delta wing L-39 could be interesting. Either tailed or tailless.
Another notion was a continuation of the pursuit-biplace series (at least a little bit further). Basically a P-63 with the 2nd seat where the Allison used to be, either with the engine up front or perhaps a twin (using Westland Whirlwind wings as I have those spare). The Curtiss V-1570 should fit in a Peregrine's dimensions. Could be developed into a nice little light attacker later.
Sorry for waffling on.
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The USN L-39 was used for low-speed handling research on swept wings, it wasn't about
exploring performance improvements. They had other projects in hand for that work.
Yeah, I know that Jon, I was thinking along the lines of an 'in-service' derivative ----
There'd be no advantage to having swept-wings on a P-63 or Fireball based aircraft,
neither could fly fast enough.
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... either with the engine up front or perhaps a twin (using Westland Whirlwind wings as I have those spare). The Curtiss V-1570 should fit in a Peregrine's dimensions...
Yeah, that Conqueror was a compact little puppy, wasn't it! The Peregrine (and Kestrel) had a smaller displacement, but was a smidge wider and longer. Dry weight for the GV-1570 was about the same - 1,015 lb (so in between the Kestrel and Peregrine).
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Direct Drive Conqueror.
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Nice :smiley: Now I'm imagining that Conqueror dropped into an ur-Airacobra (or maybe a mid-engined Consolidated A-11?).
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I may have asked before but does anyone know of a 1/48 conversion kit to make the original XP-39:
(https://upload.wikimedia.org/wikipedia/commons/b/b9/Bell_XP-39.jpg)
(https://ww2aircraft.net/forum/attachments/xp-39-paper-jpg.468582/)(https://ww2aircraft.net/forum/attachments/xp-39-paper-jpg.468581/)
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Bell Model 3 "conventional".
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Different
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Realistically an XP-39 would be better done as a full kit rather than a conversion kit as you'd
need an entire new fuselage to do it correctly. They made a lot of changes to make it into a
usable production aircraft.