Kawasaki Ki-100

[SpicyJuan11]

The He 100 was designed for dual purpose, record setting and a service fighter. Two sets of wings were designed from the start and even so, the "big" fighter wing was about as small as any service fighter used in WW II. It was almost exactly the same area as the I-16 and the I-16 wasn't trying to house fuel in the wing and use the wing surface as a radiator. They also made the tail more than a little too small to start and it needed serious enlargement after the first few flights. The fans what to take all the good (the high speed and range) and ignore the bad.

A fair amount of work wasput into the 209 to try to turn it into a fighter. an all new longer span wing was designed and then lengthened twice. different leading edges were tried. at least two different radiator set ups were tried (not counting the surface cooling set up). Larger tail surfaces were used than on the record setting plane/s. With each change to make the plane easier to fly (or to stop over heating) the performance dropped till finally it showed little difference forma service 109.

I'm somewhat confused, the Me 209 designed to replace the Bf 109 was a completely different a/c than the racing Me 209.

 

[GrauGeist]

I'm somewhat confused, the Me 209 designed to replace the Bf 109 was a completely different a/c than the racing Me 209.

You're correct...the Me209 V1 through V4 were for speed development and propeganda purposes, the Me209 (sometimes Me209 II) V5 through V8 were two entirely different aircraft.

The 1943 Me209 actually looked more like a Fw190D than anything.

 

[Shortround6]

The Me 209 V4 was the one worked over a number of times before they gave up.

The Me 209 V5 had nothing in common except the number and and some cockpit instruments

 

[GrauGeist]

Me209 V1 through V4 was the speed concept developed in 1938.
V1 (WkNmr 1185) D-INJR: first flight 1 August 1938
V2 (WkNmr 1186) D-IWAH: first flight 2 February 1939
V3 (WkNmr 1187) D-IVFP: first flight May 1939
V4 (WkNmr 1188) D-IRND/CE+BW: first flight 12 May 1939

It might be interesting to note that V4 was actually a planned armed version with two MG17s in the upper cowling and a MK108 motorkannone as well as two MG17s in the wings. The proposed wing MGs simply would not fit in the wing due to lack of space even though V4's wing area had been increased over the previous three airframes.

Me209 (RLM 8-209) V5 through V8 was the designated replacement for the Bf109 developed in 1943.
V5 (WkNmr 16281) SP+LJ: first flight 3 November 1943, powered by a DB603A
V6 and V7 have little additional information aside from the fact that V7 was fitted with a Jumo213E including an annular radiator.
V8 was officially designated Me209H V1 and was said to be equipped with a DB603G for testing and had an enlarged wing. It's first flight was in June of 1944, abouth the same time that the first batch of production Fw190D aircraft went into service with III./Jg54.


*edit*
Well, the server doesn't like my 8-209 three view for some reason...

 

[Shortround6]

You are correct but the V4 used the fuselage of the V1-V3 series married to a new wing to try to develop a service fighter. The wing was modified several times, the radiator/cooling system was modified several times, armament details are sketchy (two mgs in the cowl and some sort of cannon in the prop hub) but performance (speed) plummeted from the V1-V3 (not surprising with around 66-70% of installed power and more drag).

the only worth the V4 had was to show them what NOT to do when they tried again later.

 

[GrauGeist]

You are correct but the V4 used the fuselage of the V1-V3 series married to a new wing to try to develop a service fighter. The wing was modified several times, the radiator/cooling system was modified several times, armament details are sketchy (two mgs in the cowl and some sort of cannon in the prop hub) but performance (speed) plummeted from the V1-V3 (not surprising with around 66-70% of installed power and more drag).

the only worth the V4 had was to show them what NOT to do when they tried again later.

Agreed...the V5 and later offered nothing that the Fw190D series already provided and sooner.

 

[Shortround6]

To be somewhat fair the concept for the 209 II was to try to use about 65% of the parts from a 109G and thus make the change over/replacement easier than tooling up for a new fighter or changing to 190 production. Reality was that only 40% or less of the parts would work and performance was below estimates which meant a lot of effort changing over for marginal results.

 

[GrauGeist]

To be somewhat fair the concept for the 209 II was to try to use about 65% of the parts from a 109G and thus make the change over/replacement easier than tooling up for a new fighter or changing to 190 production. Reality was that only 40% or less of the parts would work and performance was below estimates which meant a lot of effort changing over for marginal results.

Willy also tried that with the Me309 (and the proposed Me509)

 

[kool kitty89]

Well, they should have moved the landing gear outward. It was done in experiments. Thye should have fitted a good bubble canopy. That was also done in experiments. They should have made an effort to make the Bf 109 G series lighter, and that, too, could have been done. I think they should have changeds the wing mount to be a 4-poiont rather than a 3-point. They should have made provision for more internal fuel, at least in a tank that could be used or not used as the mission required.

Willy should have worked on making the controls easier to use at higher speeds, and should have fuitted trim to the rudder at least, if not the aileron, too. None of these were majot changes except the 3-point to 4-point wing mount bolts.

I'd have though seriously about a slightly larger, scaled-up Bf 109 ... maybe 10%. There are other changes, but many could be done with little difficulty.

There are more, but you get the idea. There was nothing that could NOT have been made better or lighter. The real need was to settle on an improved design and BUILD it.
No reason THAT couldn't have been incorporated.

Agreed, particularly something better than the existing 109 (better in the operational sense not just raw performance) yet retaining production/cost advantages compared to just switching to more 190/derivatives.

I also believe the control issue was both aerodynamic and structural (heavy controls to avoid overstressing the airframe).

The 109F itself incorporated a good deal of refinements, but most were for improving speed and not other operational aspects. More compromises to allow improved landing gear would be good, perhaps along with a larger wing closer to the 109T but also working towards modifications to allow MG 151s to be mounted in the wings rather than deleting the wing guns entirely or relying on pods. (switching to MG 131s should have been structurally simpler and still allowed removing cannon MG FF bulges, but aiming at eventually getting 151s inside the wings would be really useful) Probably delete the cowl guns entirely. (redesigned wings allowing wing root guns might have been useful, though that also seems like a space well suited for expanded fuel tankage)

Improving the canopy for visibility and reduced drag would certainly be important too. (and fuel capacity)

If the 109 had been made into a reasonably well performing plane that was all around EASIER to fly than the Fw 190 as well as cheaper and easier to mass produce, it certainly would have had more merits to keep in production.


Working on a more conservative (but comprehensive) modifications to the 109 rather than all new machines like the 309 seem far more reasonable and better suited to available resources. (better than the amount invested in the Me 210 program as well) Sort of like the Me 209-II later did but starting in parallel with (or in place of) the 109F developments and focusing on the DB 601 (maybe considering the 211F as an alternative).

The He 100 seems to be something of a sacred cow among Luftwaffe fans. It just missed being a world class fighter but miss it did and nothing short of a new plane was going to "fix" it. The He 100, like some other Heinkel aircraft, was biased a bit too much to the record breaking side of the balance and not quite enough to the service fighter side. Messerschmitt spent a lot of time and effort trying to turn their 209 record setter into a service fighter. Being even more extreme than the He 100 it went nowhere.

The He 111 seems to be one of the better examples of Heinkel balancing the record setting aspects with a useful civil and military aircraft. Applying a similar balance to the He 100's development should have seen it faring much better. The He 112 seemed a lot more reasonably conservative in a number of areas too, and for a design supposedly aiming at succeeding where the 112 had failed (supposedly including lower cost/complexity/parts count) the He 100 seems to have done a pretty poor job of it.

Something designed to be more adaptable to alternate powerplants and armaments would have helped too. (I wonder if the He 111's nacelle/radiator design would have been useful to adapt to a fighter)

 

[SpicyJuan11]

...supposedly including lower cost/complexity/parts count...

In that the He 100 did not:

In comparison, the 112 had 2,885 parts and 26,864 rivets, while the P.1035 was made of 969 unique parts with 11,543 rivets.

 

[GregP]

Good points Kool Kitty.

The Bf 109's weaknesses could all have been addressed. including control forces and throws. It would have been a significant change to go from 3 wing mount locations to 4, but it also would have made the Bf 109 stronger. I'm not sure it would have resulted in a major weight gain, but would have been a bit heavier by a small amount. I've seen more than a few videos where the lower wing attach point was hit by fire and the wing just folded up around the fuselage. 4 mounts would have helped stop this in a lot of cases. You can't eliminate them all.

Considering everything, the Bf 109 was great design overall that could have been significantly improved rather easily. If they didn't do anything else, adding something as seemingly insignificant as rudder trim would have been a real boon to pilots.

 

[windswords]

To get back to the topic at hand, my take is that if you were a novice Japanese Army Air Force pilot and going to fight at low to medium altitudes then the Ki-100 would be the best choice for you. If you were a veteran and going to fight at higher altitudes, longer ranges (escort duty etc), and perform in an air superiority role, then a (well maintained) Ki-84 would be the better choice. I believe later versions were equipped with 30 mm cannons to combat the B-29's.