Heinkel He-121 Stratospheric Fighter

[dumaniac]

looks fantastic - love the outline of the wings - looking forward to the next stage

[rickshaw]

Looks interesting.  The 40mm Ho 301 is an unusual choice.  Not a terribly efficient weapon.  It had quite a short range IIRC - about 250 yards.  Muzzle drop was also quite significant because of the very low velocity (about 250 m/sec).  Basically you could watch the rounds as they were fired. 

[Stargazer]

What an interesting project! The kind of unusual yet believable aircraft I love... I'll be watching this thread closely!

[sequoiaranger]

rickshaw: >The 40mm Ho 301 is an unusual choice.  Not a terribly efficient weapon.  It had quite a short range IIRC - about 250 yards.  Muzzle drop was also quite significant because of the very low velocity (about 250 m/sec).<

I "chose" that particular weapon because it was a "large-caliber" aerial weapon already in use on some "Shoki" fighters, but I had no idea of the characteristics of the weapon. I certainly would rather feature a more efficient weapon, whether 37mm, 50 mm, or otherwise. My "alternate history" scenario supposes German-licensed 30mm cannon in use, too, so I could install them instead, but I wanted something with a little more punch--37mm or 40 mm.

I am equipping my He-121 with some "mortar"-type pulk-zerstorer weapons, but I am open to suggestions for a "bomber-destroyer" gun to go along with them!

GTX--thanks.

Stargazer2006: >What an interesting project! The kind of unusual yet believable aircraft I love<--I try to keep my whifs in the realm of reality, generally making them "extrapolations" rather than wholly new designs.

In my research of German high-altitude fighters, I am a little taken aback that the Germans got on the high-altitude bandwagon so late. That is, they did foster high-altitude BOMBING and recon aircraft early on, but never thought of high-altitude FIGHTERS until late in the war. My scenario supposed an early initial interest (mainly for world prestige in holding records), with flagging subsequent development until late in the war.

[The Wooksta!]

Their high altitude fighter developments were on the go from mid-late 1942.

Interestingly, this has made me think about that Novo Bristol 138 that's sitting in the stash anda set of wrecked Blenheim bits...

[sequoiaranger]

The Monogram Bf-110 is a beautifully done model, and comes with the "up-and-down" exhausts so characteristic of its type. Originally, I had envisioned twin exhausts for my He-121 like my previous Hawker Henley project (somewhat similarly-configured engine). Instead of simply exhausting directly into the air, I had my pipes "Y"-ing into a single pipe heading down to the turbocharger. Then I stumbled upon, and adopted, this dual arrangement of "down-and-up" exhaust headers to be collected into a SINGLE manifold. "My" engine is an X-16, so the original six-exhaust manifold (held by my fingers) was cut to four apiece, then "collected" into a shaped piece of sprue. The sprue will be shaved down to "half" and run along the fuselage "half-in and half-out" in a simulated metal trough to the scoop below (see the Focke-Wulf 190 V-18 boxtop deeper in this thread--the pipe ran whole on the outside of the fuselage inside a fillet).

[sequoiaranger]

Wooksta: >Their high altitude fighter developments were on the go from mid-late 1942.

Interestingly, this has made me think about that Novo Bristol 138 that's sitting in the stash anda set of wrecked Blenheim bits...<


Höhenjäegers (High-altitude fighters) might have been started in 1942, but that was a two-year lag from the bomber/recon aircraft (Ju-86P flown in 1940). One would have thought they would have been contemporary.

Bristol 138, eh!! Go for it! My "backstory" for the He-121 will say something like, "though other countries were flying RESEARCH planes higher and beyond German efforts, Germany saw the potential to "militarize" the lower stratosphere with sturdy planes capable of payloads (weapons or ordnance). Like many of Germany's ostensibly civilian aircraft, they were overbuilt, with an eye to future military applications."

[jcf]

Craig, another actual heavy gun option used by the IJA is the 37mm Ho 204 used in the Ki 46 III kai.
It was the largest calibre Browning action gun built (it looks like a monster M2) and had a muzzle velocity
of 450m/s and a rate-of-fire of 400 rpm.


http://gunsight.jp/b/english/data/ja-gun-e.htm

The guns page is from a good Imperial Japanese aircraft equipment reference page:
http://gunsight.jp/b/

Jon

[sequoiaranger]

I decided to primer-spray my Heinkel to find out all the ugliness that needs beautification, and of course there were plenty! However, attaching temporarily some pieces for the photo, you can get an idea of how it will turn out. The turbo-pipes are there (one side), but not the armament (cannon in the wing projections, and underwing mortar tubes). You can see the outlines of the cabin module that can eject with the pilot inside. The small canopy reminds me of the high-altitude Tachikawa Ki-74 "Patsy" (bomber). I'm excited! But there is a LOOOOONG way to go, actually.



This rear-quarter view exposes the huge ventral scoop that will eventually tie all the plumbing together.



>Craig, another actual heavy gun option used by the IJA is the 37mm Ho 204 <

Funny you should post that JUST as I was about to put this post up---I had been looking at Japanese aircraft cannon and decided on the H0-204 for my Heinkel!

[jcf]

>Craig, another actual heavy gun option used by the IJA is the 37mm Ho 204 <

Funny you should post that JUST as I was about to put this post up---I had been looking at Japanese aircraft cannon and decided on the H0-204 for my Heinkel!

Great minds and all that. 

[frank2056]

Craig,
If this is a tail sitter, the pilot's going to have a fun time lining up on the runway and taking off. With wings that big, the takeoff run would probably be short, though.

FRank

[GTX]

Looks great!!!

Regards,

Greg

[TallEng]

It Just shouts PRU Blue! (or the Japanese equivalent) 
or is that just me?
O.K. I'll go quietly
Nice job

[GTX]

Re the guns, say they were chosen so as to fire large explosive shells thus ensuring maximum impact upon the target.

regards,

Greg

[sequoiaranger]

>It Just shouts PRU Blue! (or the Japanese equivalent)<

Kind of. The BOTTOM of the plane will be a dark blue, as the blue "sky" at high altitudes is VERY dark. The top will be a hazy, light blue-gray, with some landscape elements. I want the "bandages" around the Hinomaru on the sides and bottom (to protect against itchy trigger fingers on Japanese AA guns), but a dull Hinomaru on top. I'll have the "Chrysanthemum/River" motif on the tail. Three pointing-down "Bombers" kill markings, plus a red star (for a Russki kill). Maybe a plane number.

But...I am getting ahead of myself. I still need to clean up a whole lot of gaps and rough spots (the time-honored PSR), fabricate the exhaust-driven turbo setup, fabricate and install armament, and figure out the landing gear (heights, wheel diameters, wheel cover configuration, and the outrigger wheels) before I get to "decorate".

>If this is a tail sitter, the pilot's going to have a fun time lining up on the runway and taking off. With wings that big, the takeoff run would probably be short, though.<

I think the cockpit is positioned far enough forward to see over the nose, especially if the pilot is standing up while lining up on the runway. And yes, the plane will lift off quickly--this bird can CLIMB!

>Re the guns, say they were chosen so as to fire large explosive shells thus ensuring maximum impact upon the target.<

Yes! We are talking BIG BOMBERS here, so puny 7.7's aren't going to cut it. The underwing mortars are three-chambered for ripple-firing or single. I have the mortars configured three horizontally (cut down from a "Screaming Mimi")---a recent Me-262 whif had three mortars in a triangular formation---more "advanced".
I need to put pointy rocket heads in one end, and tailfins in the other, but here they are:



>Looks great!!<

I would have to agree