He 100 in service, but with caveats

[tomo pauk]

Be careful when you list the performance of prototype aircraft. It takes years to go from flying prototype to production and lots of aircraft in service.

Were the He-100's performance figures done with full armament, a full load of ammunition and fuel, and contemporary armour? Ernst Heinkel was into high speed flights.

Rest assured, I have no intention of listing Heinkel's performance figures - these will be unobtainable on same HP and 'classic' cooling system. As one can see, I'm trying to find the performance figures of actual combat aircraft that are of comparabe size and streamlining, like the VG33, B.135, D.520, Yak-1, MC.202, and then try to see how well a similar He 100 (= same or similar power, 'classic' cooling) might compare.

The He-100's armament was inadequate. How do you increase it? The He-100 was a tiny airplane. There was nowhere to stuff a pair of MG151/20s.

MG 151/20 was not be-all end-all weapon set up. One MG FFM or indeed MG 151/20 should fit as a motor-cannon. Install MG 131s in the wing roots and in the wing, now that it does not have steam running around.
However, there is two years of ww2 before we stumble upon the MG 151/20.

What happens if some other manufacturer develops a high performance aircraft that uses BMW801 radials instead of the DB601s reserved for Messerschmitt?

Then the Allies have a problem, not Luftwaffe.

Are the engines shrunk to be able to fit somewhat smoothly to the airframe in the above two drawings? They seem it to, as the He 100 airframe was "small".

I can talk about my ... brainchild. Note that cooling system protrudes well under the fuselage - than it was not the case with 'donor' aircraft (Avia B.35/135).
Unfortunately, I'm not aware of a model of such an aircraft.

 

[Shortround6]

You can pretty much forget the H-S engine. You are down about 200hp. You cannot make up the difference with simple tweaks.

Install MG 131s in the wing roots and in the wing, now that it does not have steam running around.
However, there is two years of ww2 before we stumble upon the MG 151/20.

You also have about 2 years or more before the MG 131 shows up in quantity.
There was a mockup or prototype with four 7.9mgs in the wing roots so that isn't that big a problem.

 

[tomo pauk]

You can pretty much forget the H-S engine. You are down about 200hp. You cannot make up the difference with simple tweaks.

Simple tweaks for the Czech HS 12Y would've probably involved retrofit of a bigger and/or more efficient S/C from on it - the original S/C was underwhelming (as noted in France). Reduces difference to 10% above 4 km vs. DB 601? Keep it still 1-speed drive.
(more comprehensive tweaks might be installation of the fuel injection + cams for the greater valve overlap, for 1000 HP and improved fuel economy)
A 840-920 HP engine on the He 100 still leaves a fighter as fast as the Bf 109E (had a lot to do with 109E having lumps and bumps everywhere), and more importantly, able to deal with any Allied A/C until Spitfire. Add fuel to the place where the oil cooling system was (just behind the pilot) or in front of the main spar for greater range/radius.

 

[Shortround6]

Simple tweaks for the Czech HS 12Y would've probably involved retrofit of a bigger and/or more efficient S/C from on it - the original S/C was underwhelming (as noted in France). Reduces difference to 10% above 4 km vs. DB 601?

the main problem with the big Hispano is that it dates from 1928 if not before (early versions were not supercharged) and while Hispano did a good job keeping up during the early/mid 30s the engine was just getting too long in the tooth for WW II.
The basic engine was already being pushed to it's limits, which is why all of the big Hispano modifications, Swiss modifications and Soviet modifications gained weight, more valves, new superchargers/drives, and often sacrificed engine life.
The Soviets had tweaked it somewhat just to get the M-103 versions which started showing up in 1936, The M-103A introduced the bore reduction to 148mm to strengthen the cylinder walls. Among other things the M-105 changed from 2 valves per cylinder to 3 valves per cylinder (two intake, one exhaust).

RR didn't change the Buzzard from 1140lbs to over 1700lbs (Griffon) simply putting a bigger supercharger on it.

 

[tomo pauk]

the main problem with the big Hispano is that it dates from 1928 if not before (early versions were not supercharged) and while Hispano did a good job keeping up during the early/mid 30s the engine was just getting too long in the tooth for WW II.
The basic engine was already being pushed to it's limits, which is why all of the big Hispano modifications, Swiss modifications and Soviet modifications gained weight, more valves, new superchargers/drives, and often sacrificed engine life.

I'll admit that Hs 12Y in front of the He 100 is a way to have the He 100 in series production without too much of rocking the boat while still having an useful fighter. It took a workaround via A-36 to have P-51 design to survive and became an over-perfomer, so I'm not that cheeky.
Even with nip and tuck, the HS 12Y will probably be limited to under 1100 HP (low altitude figure; 1000 HP at higher altitudes) judging by what French did before the 12Z model. Should be enough to have a 600 km/h He 100.
(the 1000 HP low-altitude Y-51 was with HS supercharger, impeller of 225mm - vs. 240 mm on the 'normal' fighter engines; it turned at 10 times the crankshaft speed, same as HS 12s on their fighters)

Granted, the Jumo 211 will be a better choice.

 

[Zipper730]

How did anybody conclude the He100 would be a combat reliable aircraft? Sure, I can see how it'd make a good racer, but there's so many areas where you could ventilate the cooling system.

 

[tomo pauk]

How did anybody conclude the He100 would be a combat reliable aircraft? Sure, I can see how it'd make a good racer, but there's so many areas where you could ventilate the cooling system.

Are you referring to what Heinkel was saying, or to the premise of this thread?

 

[GrauGeist]

How did anybody conclude the He100 would be a combat reliable aircraft? Sure, I can see how it'd make a good racer, but there's so many areas where you could ventilate the cooling system.

The production model had a conventional cooling system with a radiator.

 

[tomo pauk]

The production model had a conventional cooling system with a radiator.

There is no German source that confirms this.

 

[Shortround6]

The production model had a conventional cooling system with a radiator.

There is some dispute about that. Yes a rather large radiator was fitted

Under the cockpit and about the full width of the fuselage. It was retractable for different flight conditions.
However it does not seem to have replaced the surface cooling system but supplemented it.
Other pictures of these "He 113s" in bogus markings show alcohol filling sites for the oil cooler and for filling the cooling system (that one is in the front of the cowl on the other side.) And it is supposed to need distilled water.

If we stop and really think about the He 100 we can see a number of flaws as an operational aircraft. A number of other fighters and bombers had cooling problems while warming up, taxiing and take-off. Most of those (all?) had the prop blast blowing through the radiators or engine cowl/ducts. The HE 100 had a fair amount of the cooling surfaces in the wing outside of the prop disk. Once you are up to cruising speed everything may be wonderful but until then?

 

[GrauGeist]

There is no German source that confirms this.

Plenty of photos existing that show the radiator in place.

An evaporative system is not compatible with a conventional system - it could not have both.

 

[Shortround6]

Plenty of photos existing that show the radiator in place.

An evaporative system is not compatible with a conventional system - it could not have both.

And yet the He 119 is supposed to have had both.

 

[Zipper730]

GrauGeist
My memory seems to conform to what you said, that the aircraft was to have surface evaporative cooling but depended on a retractible cooler for lower speed flight.

Regardless, most information seems to indicate that the operational aircraft used surface-evaporative cooling while at high speed, and that brings me back to what I said to begin with: I'm amazed they ever thought such a system could be suitable for combat.

S Shortround6
I never knew that the aircraft was to have a surface evaporative cooling system with an auxiliary extendible cooler for low-speed flight.

D Deleted member 68059
The He 100's cooling system used pressurization correct? If you have any further information: Do you have any information as to what pressures were used?

 

[tomo pauk]

Plenty of photos existing that show the radiator in place.

An evaporative system is not compatible with a conventional system - it could not have both.

That was a pop-out auxiliary radiator, deployed until aircraft was at sufficient forward speed.

 

[wrenchedmyspanner]

I'll admit that Hs 12Y in front of the He 100 is a way to have the He 100 in series production without too much of rocking the boat while still having an useful fighter. It took a workaround via A-36 to have P-51 design to survive and became an over-perfomer, so I'm not that cheeky.
Even with nip and tuck, the HS 12Y will probably be limited to under 1100 HP (low altitude figure; 1000 HP at higher altitudes) judging by what French did before the 12Z model. Should be enough to have a 600 km/h He 100.
(the 1000 HP low-altitude Y-51 was with HS supercharger, impeller of 225mm - vs. 240 mm on the 'normal' fighter engines; it turned at 10 times the crankshaft speed, same as HS 12s on their fighters)

Granted, the Jumo 211 will be a better choice.

Is a radial out of the question?

 

[Steve Hnz]

Is a radial out of the question?

Can't see why it should be. Japan turned the Ki 61 into the Ki 100 in short order & came up with a better aircraft. Minimal airframe mods afaik, other than from the firewall forward.

 

[Shortround6]

Japan turned the Ki 61 into the Ki 100 in short order & came up with a better aircraft.

In practice the Ki-100 performed better but that was due to the Engines in the Ki-61 not performing as they should.
One book (could be wrong) says max speed for the Ki-100 was 360mph at 6,000 meters. Time to 5,000 meters 6 minutes
Ki-61 I-KIA-Hei was supposed to do 360mph at 5,000 meters. Time to 5,000 meters 7 minutes

Problem with this is that the Ki-100 was not a replacement for the Ki-61 I-KIA-Hei with it's HA-40 engine that offered 1100hp at 4200 meters.
The Ki-100 was built because the HA-140, which was supposed to give 1250hp at 5,700ft was a failure.

The engine in the Ki-100 gave 1250hp at 5,800 meters.

When the HA-140 engine ran correctly (rare) the Ki-61 II could do 379mph at 6000 meters and climb to 5,000 meters in 6 minutes. A bit off from predictions by 8 and 6 percent respectively.
The Japanese couldn't keep the HA-140 running long enough to equip service squadrons with them (or not very many) so the Ki-61 II KIA (about 99 built and 1/3 of them destroyed in an air raid) never established a combat record.

The narrative that the Ki-100 with it's radial engine was superior to the Ki-61 (type not given) tends to gloss over that. One would hope that a 1944/45 radial was better than a 1941-42 licensed V-12. Production of the Ki-61 was painfully slow but it was a 1941-42 design.

 

[tomo pauk]

Is a radial out of the question?

I have no problems with a radial in the nose. It serves a purpose if the country making He 100s has a questionable supply of good V12s, but their radials work and are readily available. Japanese can fit here, Swedish (with R-1830, so they make this instead of the J22). Yes,it will gain some drag, but it produces a workable and useful fighter.
For the Japanese, He 100 paired it with Zuisei or Sakae should've worked the best. Result would've been a much faster fighter than the Zero or Oscar, probably in the ballpark of the Tojo?
Radial engine installation by default removes all the volume requirements in the wing for the steam and water, thus the gain in internal volume is substantial. Also the oil system is a conventional one, that means the volume just behind the pilot is now available for fuel.

 

[GTX]

What if Heinkel followed the Focke-Wulf example and offered a version with a air-cooled radial instead thus avoiding the whole DB 601 supply and evaporative cooling issues:

View attachment 693347

At the risk of repeating myself...

 

[GTX]

I have no problems with a radial in the nose. It serves a purpose if the country making He 100s has a questionable supply of good V12s, but their radials work and are readily available. Japanese can fit here, Swedish (with R-1830, so they make this instead of the J22). Yes,it will gain some drag, but it produces a workable and useful fighter.
For the Japanese, He 100 paired it with Zuisei or Sakae should've worked the best. Result would've been a much faster fighter than the Zero or Oscar, probably in the ballpark of the Tojo?
Radial engine installation by default removes all the volume requirements in the wing for the steam and water, thus the gain in internal volume is substantial. Also the oil system is a conventional one, that means the volume just behind the pilot is now available for fuel.

View attachment 700857

The benefit of a radial engined version would have been more the availability of engines such as the BMW801. This is the same reason the Fw190 got ahead - it offered a new fighter that didn't cause more pressure on the DB601/605 production capacity.