Hehe, that’s not a P-39 that’s a pre-WWII Bell Model 3 interceptor, progenitor of both the Airacobra and the XP-77.
WWII replica plans available in 2021?
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Hehe, that’s not a P-39 that’s a pre-WWII Bell Model 3 interceptor, progenitor of both the Airacobra and the XP-77.
Take a look at this cutaway and 3-view, the pilot is already very close to sitting on the main spar, it’s totally doable with a light engine and/or a prop extension. Cheat the cockpit a little aft and the wing a little forward and you’re all good. Maybe use a 100 hp Aeromomentum AM13 or other small Suzuki conversion? I’ve even got my color scheme all picked out.
And with the liquid cooled engine you could even put the radiator under that scoop aft of the canopy. The exhausts from the front mounted engine will have to be hidden somewhere.
I think I'd rather fiddle with the wing and the tail volume to move the CG. Maybe a little more chord towards the aft end, a little change in stabilizer size, a little different sweep...lots of ways to move CG around without getting away from the general proportions of the original. Still, it's a replica, so a certain amount of liberty has to be figured in.
If you need weight up front, what about a beefy metal (tubular?) bathtub from the back of the cockpit forward for pilot protection. Something along the lines of the A-10 bathtub though it doesn't have to be solid nor made from Titanium.
You'd want something to prevent the engine from ramming forward in the event of a crash anyway.
Make the entire structure from the back of the cockpit to the prop one solid, very strong cage that survives even if the wings and tail are mashed.
You'd want something to prevent the engine from ramming forward in the event of a crash anyway.
Make the entire structure from the back of the cockpit to the prop one solid, very strong cage that survives even if the wings and tail are mashed.
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Just for grins, I'm going to put a P39 canopy on my H5 build. Rework the turtle deck and do a molded 3 piece canopy. This drawing is of the conventional gear, so maybe an Airabonita instead, or build it tri gear and reshape the rudder/V-stab for a more 40s outline. Tack on some fake exhaust stacks and a little custom fiberglass cowling, who knows, it might be cute!
Remote avionics, dual batteries, hydraulic pumps for the gear, beefy nosegear, landing lights, antennae, oxygen bottle, air vents for the pilot and attendant tubing - all up front.
Put everything you can think of up front.
Put everything you can think of up front.
That doesn’t really define aerobatic capability. Almost any airplane can do that with the right pilot.
BJC
Yeah, maybe the inverted oil setup and fuel pumps can help with the CG issues! I do need to reckon on the right camera setup to capture the glorious exploits!Gotta pull loops and immelmans and split S-s or it's just not worth it
If one insists on the rear / mid mounted engine, look again at the cutaway drawing. The original P-39 (and P-63) had the radiator cooling ducts mounted at the roots of the wings. Using this, one could mount an opposed air cooled engine low and behind the pilot and duct the cooling air through the wing spars and back to the engine. OR a Subaru conversion or even Rotax opposed 4 stroke could be used. Dennis
Are you reading my mind? I thought about using a Corvair conversion mounted in the original spot, using the wing root ducting for the cylinder and oil cooler air flow. Still have to figure out the drive shaft vibe dampening. And the redrive, though I shouldn't need any reduction with the Corvair.
Great minds think alike . Back in the day, I've owned about 25 Corvairs (the cars, pickups, vans). A few years back I completely rebuilt the engine in a 65 Greenbriar van that a friend's wife had bought. Corvair + P-39. Nader would hate it. Dennis
. Back in the day, I've owned about 25 Corvairs (the cars, pickups, vans). A few years back I completely rebuilt the engine in a 65 Greenbriar van that a friend's wife had bought. Corvair + P-39. Nader would hate it. Dennis
flitzerpilot
Well-Known Member
Based on the 'proposed ' XP-77/P-39 hybrid and the later question whether an early Yak type was similar; in fact the early Yaks right up to the Yak-9 T tank-buster all had relatively forward located cockpits. But the closest long-nosed production Russian fighter of the day was the MiG 3. I've looked at this for a Jabiru flat 6 installation but the Aeromomentum or even a Rotax could be buried within the nose behind the relatively large spinner. Indeed, due to the bilateral supercharger intakes, even a Corvair could work. I did design a fixed gear monoplane 'fighter trainer' around a Corvair and built a small model to see how such an installation might look. As the Corvair only measures 29" across the rocker covers (compared to about 32" for a VW) i think is looks OK if these are considered to be similar to the intakes on the MiG 3. I attach some speculative drawings of this, the 'Baturin SK35', and of the MiG 3 to 60% scale with a close-up of the MiG nose included for ref. (The 'kink' in the frontal aspect of the Baturin drawing wing is an illusion.)
Incidentally one Yak 1 (or 3) example was built with large flame-damping exhaust covers which look exactly like the fairings for an air-cooled flat 4 or 6 installation. Unfortunately it was a one-off, so if built as a scaled-down fighter with a Corvair, most people would think it was a failed attempt at authenticity.
Incidentally one Yak 1 (or 3) example was built with large flame-damping exhaust covers which look exactly like the fairings for an air-cooled flat 4 or 6 installation. Unfortunately it was a one-off, so if built as a scaled-down fighter with a Corvair, most people would think it was a failed attempt at authenticity.
Attachments
Lynn, that Baturin "fighter trainer" is great, definitely captures the spirit of the Soviet designs of the era without being a replica of any one aircraft. Presumably a Suzuki conversion might also work, something like the Aeromomentum AM13 or AM15 or the equivalent AirTrikes models. The asymmetry of the canted, low-profile models (AM13 below) would not scream "there's a flat engine under here".
Take the lower cowl off and you might scream, "there's a LOT of plumbing under here!" Look at that exhaust system! I wonder what it weighs?
flitzerpilot
Well-Known Member
Yes, Matt. The Aeromomentum opens up a new field for water-cooled scaled fighter types in its 'inclined' form and in upright mode will serve well for WW1 machines. The exhaust system and silencer could be avoided and just stubs emerge from one side for the inclined motor with mock-up pipes (and exhaust stains) on the opposite side the nose. That would suit an inverted 'V' simulation, such as on an Me 109.
ScaleBirdsScott
Well-Known Member
The AM engines could be setup with all sorts of intake and exhaust confabulations as needed for a variety of warbirds.
I'm more and more a fan of wanting to build a little Yak-3. After seeing the Czech-made replica on Youtube, it looks so appealing.
I'm more and more a fan of wanting to build a little Yak-3. After seeing the Czech-made replica on Youtube, it looks so appealing.
I’ve already got my Yak paint scheme picked out! The perfect canvas for those fake exhaust stains….
Yak-1B « 44 rouge »
Sous-lieutenant Marcel Albert
3e Groupe de Chasse « Normandie »
Mars 1943
Yak-1B « 44 rouge »
Sous-lieutenant Marcel Albert
3e Groupe de Chasse « Normandie »
Mars 1943
