N1K, J2M and Ki-44 vs. 1941 and 1942 vintage Bf 109

[Wild_Bill_Kelso]

This originates with a N1K2 vs. Bf 109 "of 1941 vintage", but I'll expand it to include any (non floatplane) version of N1K, and maybe later we can layer in J2M and Ki-44.... vs Bf 109F2, F4, G2, or G4, and G6 if they have some before the end of 1942. I don't think they were in the Med that early but I don't know the production history that well so willing to learn that they were available.

I still put the N1K2 on top of any of those. Why?

N1K2 is, at least if what I can find online is accurate, is faster than an F-4, and I think faster than a G-2 or G-4 though I'm not certain.

This says the following about N1K1

Speed: 408 mph / 656 kph at 20,000 ft., 360 mph at ~4,000 ft, 340 mph at sea level. I don't know the maximum dive speed.

Climb: 3875 fpm at sea level, 4065 at 5,900 ft

Gross Weight 7717 lbs / 3500 kg
Wing Area: 253 sq ft.
Span: 39.4'
Engine: Homare 21, 1975 HP takeoff, 2050 at WEP (2500') 2 speed supercharger
Fuel: 125 gal internal + 87 gal drop tank, total 212 gal
Range 1085 miles at 167 with external tank, 830 miles at 237 mph

Power to weight: .25 for takeoff, .26 at WEP
Wing loading: 30

Has maneuvering flaps. Armor and self sealing fuel tanks. Roll rate is reported as 82 degrees per second at 240 mph. (I don't have the source for that though)

So I say this outruns (at all altitudes), out-climbs, and definitely out turns a Bf 109F2 or F4, likely out rolls it too, while carrying twice the fuel and heavily outgunning it.

I'm not sure on the speed of a G-2 or G-4, maybe somebody can clarify. Some versions of the G-6 are a bit faster than 408 mph, but the N1K1 seems to stilll have the edge in climb and for sure turn rate.

 

[PAT303]

Everything I have read about the Homare has been negative, it was difficult to make, difficult to service and didn't meet it's rated power.

 

[Wild_Bill_Kelso]

Ok so let's assume that's true, give it a 40% less availability rate. Let's say 5% less power. 10%? I think it's still running rings around a Franz

 

[tomo pauk]

This originates with a N1K2 vs. Bf 109 "of 1941 vintage", but I'll expand it to include any (non floatplane) version of N1K, and maybe later we can layer in J2M and Ki-44.... vs Bf 109F2, F4, G2, or G4, and G6 if they have some before the end of 1942.

This was how it started:

N1K2-J - a bit better, but still worse in performance vs. the best what the West was making. The German fighters of 1941 will give it a good run for it's money, and then some.

N1K2 is, at least if what I can find online is accurate, is faster than an F-4, and I think faster than a G-2 or G-4 though I'm not certain.

This says the following about N1K1

Speed: 408 mph / 656 kph at 20,000 ft., 360 mph at ~4,000 ft, 340 mph at sea level. I don't know the maximum dive speed.

Japanese say ~380 mph top speed.

 

[PAT303]

Ok so let's assume that's true, give it a 40% less availability rate. Let's say 5% less power. 10%? I think it's still running rings around a Franz

Japan's top brass obsession with the Homare

How many airplane designs where ruined, delayed or not brought by their fullest potential by the Japanese's top brass (both IJA and IJN were equally guilty) obsession with the Homare? I can think of a few of them, but this is not a 'what if post' but rather an attempt to understand why the...

ww2aircraft.net

 

[wuzak]

According to Wiki, the first flight of the N1K1-J was December 1942 and had a top speed of 408mph.

The first flight of the N1K1 was May 1942.

The first flight of the N1K2-J was the last day of 1943.

Production of the N1K1 started in August 1942 and 3 were completed by the end of 1942, 12 by the end of July 1943.

Production of the N1K1-J started in July 1943, and the first production N1K2-J was December 1943 (only one for 1943).

The N1K1 entered service in 1943, but was a float plane.

The N1K1-J entered service in 1944.

So I doubt that any N1K variants were troubling much of anything in 1942.

 

[Vincenzo]

The alone available in 1942 would be the Ki 44

 

[MikeMeech]

This originates with a N1K2 vs. Bf 109 "of 1941 vintage", but I'll expand it to include any (non floatplane) version of N1K, and maybe later we can layer in J2M and Ki-44.... vs Bf 109F2, F4, G2, or G4, and G6 if they have some before the end of 1942. I don't think they were in the Med that early but I don't know the production history that well so willing to learn that they were available.

I still put the N1K2 on top of any of those. Why?

N1K2 is, at least if what I can find online is accurate, is faster than an F-4, and I think faster than a G-2 or G-4 though I'm not certain.

This says the following about N1K1

Speed: 408 mph / 656 kph at 20,000 ft., 360 mph at ~4,000 ft, 340 mph at sea level. I don't know the maximum dive speed.

Climb: 3875 fpm at sea level, 4065 at 5,900 ft

Gross Weight 7717 lbs / 3500 kg
Wing Area: 253 sq ft.
Span: 39.4'
Engine: Homare 21, 1975 HP takeoff, 2050 at WEP (2500') 2 speed supercharger
Fuel: 125 gal internal + 87 gal drop tank, total 212 gal
Range 1085 miles at 167 with external tank, 830 miles at 237 mph

Power to weight: .25 for takeoff, .26 at WEP
Wing loading: 30

Has maneuvering flaps. Armor and self sealing fuel tanks. Roll rate is reported as 82 degrees per second at 240 mph. (I don't have the source for that though)

So I say this outruns (at all altitudes), out-climbs, and definitely out turns a Bf 109F2 or F4, likely out rolls it too, while carrying twice the fuel and heavily outgunning it.

I'm not sure on the speed of a G-2 or G-4, maybe somebody can clarify. Some versions of the G-6 are a bit faster than 408 mph, but the N1K1 seems to stilll have the edge in climb and for sure turn rate.

Hi
The only book I have found that has a top speed near 408 mph is 'Aircraft of the Fighting Powers' Volume VI, 1945 (published just after the end of the war). Page 51 has the Maximum Level Speed as 407 mph (651 Km./hr.) at 20,000 ft. Maybe, like the March 1945 document in your post, it was still awaiting revised performance details because later publications tend to have a reduced max speed.
'Japanese Aircraft of the Pacific War' by Francillon, page 329 has N1K1-J as 363 mph at 19,355 ft, N1K2 as 369 mph at 18,375 ft.
'War Planes of the Second World War Fighters Volume Three' by Green, has on page 6, N1K1-J as 362 mph at 17,715 ft, page 9, N1K2-J as 369 mph at 18,370 ft.
'Concise Guide to Axis Aircraft of World War II' by Mondey, has on page 140, N1K2-J as 370 mph at 18,370 ft.
'The Fighter Aircraft Pocketbook' by Cross, has on page 178, N1K1-J as 362 mph at 19,360 ft.
'Fighters 1939-45, Attack and Training Aircraft' by Munson, has on page 48, N1K2-J Model 21 as 369 mph at 18,375 ft.
'The Complete book of Fighters' by Green and Swanborough, has on page 315, N1K1-J as 362 mph at 17,715 ft, and N1K2-J as 369 mph at 18,370 ft.
I am sure there are plenty of other print sources, but it appears if published after 1945 the maximum top speed is nowhere near 408 mph.
To do comparisons with other fighters then more in depth research may be necessary.

Mike

 

[MikeMeech]

Hi
Additional to my previous post, I thought I would have a look at my 1954 print of the OH of the RAF 'Royal Air Force 1939-45, Volume III, The Fight is Won' by Hilary St. George Saunders. Page 411 has Appendix X that gives the performance figures for Japanese aircraft. For George 11 it gives a maximum speed of 416 mph at 19,000 ft. However, a previous owner (Sqn. Ldr. A D Burt, if I have his name right from his signature inside the front cover) has amended the figures in pencil as 369 mph at 18,370 ft. sourcing the revised figures as from 'Flying Review, Feb. 1961', so I assume there was a rethink on Japanese aircraft performance during 1960/61 time period. The original performance figures are said to have be taken from "official Japanese sources, but the nature of the trials under which the performances quoted were attained, is unknown."

Mike

 

[Vincenzo]

imho the 362 and 369 mph or better the 315 and 321 kts are the speed as the japanese manual,
we know that japanese manual do not report the max speed for the max power but for... i don't remember if it is military power or rated power

 

[JoblinTheGoblin]

imho the 362 and 369 mph or better the 315 and 321 kts are the speed as the japanese manual...

I can't entirely parse your sentence, but the manual, as shown in this thread, lists a different speed for the N1K2-J, 330kt at 6000m with a weight of 3800kg, and powered by a de-rated Ha-45-21, apparently due to issues with reliability. Not 321 kts or 315 kts, the latter the N1K1-J's speed.

 

[Vincenzo]

very good, i've forget that the manual speed were shown so the trouble on the speed is over, someone misinterpreted the number 315 and 321 as the speed for the 1-J and the 2-J and not the the actual real test speed, with not full working engine, and calculate speed for full working engine

 

[Wild_Bill_Kelso]

According to Wiki, the first flight of the N1K1-J was December 1942 and had a top speed of 408mph.

The first flight of the N1K1 was May 1942.

The first flight of the N1K2-J was the last day of 1943.

Production of the N1K1 started in August 1942 and 3 were completed by the end of 1942, 12 by the end of July 1943.

Production of the N1K1-J started in July 1943, and the first production N1K2-J was December 1943 (only one for 1943).

The N1K1 entered service in 1943, but was a float plane.

The N1K1-J entered service in 1944.

So I doubt that any N1K variants were troubling much of anything in 1942.

You missed the premise of the thread, see Tomo's post. Nobody was claiming N1K were flying combat missions in 1942.

 

[Wild_Bill_Kelso]

Hi
The only book I have found that has a top speed near 408 mph is 'Aircraft of the Fighting Powers' Volume VI, 1945 (published just after the end of the war). Page 51 has the Maximum Level Speed as 407 mph (651 Km./hr.) at 20,000 ft. Maybe, like the March 1945 document in your post, it was still awaiting revised performance details because later publications tend to have a reduced max speed.
'Japanese Aircraft of the Pacific War' by Francillon, page 329 has N1K1-J as 363 mph at 19,355 ft, N1K2 as 369 mph at 18,375 ft.
'War Planes of the Second World War Fighters Volume Three' by Green, has on page 6, N1K1-J as 362 mph at 17,715 ft, page 9, N1K2-J as 369 mph at 18,370 ft.
'Concise Guide to Axis Aircraft of World War II' by Mondey, has on page 140, N1K2-J as 370 mph at 18,370 ft.
'The Fighter Aircraft Pocketbook' by Cross, has on page 178, N1K1-J as 362 mph at 19,360 ft.
'Fighters 1939-45, Attack and Training Aircraft' by Munson, has on page 48, N1K2-J Model 21 as 369 mph at 18,375 ft.
'The Complete book of Fighters' by Green and Swanborough, has on page 315, N1K1-J as 362 mph at 17,715 ft, and N1K2-J as 369 mph at 18,370 ft.
I am sure there are plenty of other print sources, but it appears if published after 1945 the maximum top speed is nowhere near 408 mph.
To do comparisons with other fighters then more in depth research may be necessary.

Mike

I've seen that ~360 mph claim for many years, and in many books too. Twentieth century aviation books copied from one another or from the same not very rigorous sources many times, in the process often repeating myths and tropes with little bearing on reality.

The 410-415 mph estimates seem to be more recent (including on the Wiki page though that means very little). I think this comes from wartime documents, or postwar testing, but I'd love to see more actual sources, all I could find is the link I already posted from WW2aircraftperformance. Which shows the 408 mph / 353 knots at 20,000 ft, and an (also very impressive) speed of 355 mph / 308 knots at sea level. That form looks to me like a postwar US form. I don't know what their source as, though it seems pretty detailed.

The discrepancy as I see it, could be down to three things:

De-rated engine running at 85-90% of what it was supposed to produce
Tests at military power rather than WEP + methanol (maybe they didn't have the methanol mix available at the time, or didn't want to risk it)
Tests with external fuel tank

If the max speed, with methanol injection, was ~365 mph at 20,000 ft, then I concede it was an inferior aircraft. If, as this government document states, it was 408 mph at 20,000 ft, I don't think it's so inferior and it is certainly competitive with a Hellcat, or with any 1941 or 1942 vintage German fighter including both Me and Fw 190.

I would say given the weight and dimensions of the aircraft, and the reported power of the engines, I would expect the higher speed is more likely, unless they were having major problems with the engine that they couldn't resolve. If that was the case though I kind of wonder if they would continue to develop it.

 

[Shortround6]

I would note that the documents on WWIIaircraftperformance seem to intelligence briefings?
Most of them seem to be 'dated' March of 1945 or DEc 1944 and reprinted in March 1945 and make no references to actually test flights or a particular captured aircraft.
Some do but they are different in layout.
Many make reference to Methanol but aside from power (?) make no reference to manifold pressure.
Some of the speed curves look a little strange. Like War emergency power levels offering improvement at all altitudes up to 35,000ft or so for the Oscar 2 and rating the Oscar at 347mph at 20,000ft? Also using Methanol on the Tojo 2?

Most of War Emergency ratings are given at altitudes where the engine would be in low blower and several thousand ft lower than the normal full throttle height, which is entirety consistent with how most engines operate. If the fuel (or methanol/water injection) allows it you can get more pressure from the blower at lower altitude, it doesn't do much for power above FTH. though. US Navy tried it on the F6F and F4U and they got something due to the cooling effect but nowhere near the effect below FTH.
Japanese didn't have the higher octane fuel but it they were setting up their engines to have extra supercharging capacity that they weren't/couldn't use is seems counter productive.
See Merlin 46 which made about 100hp less than Merlin 45 until it got near 20,000ft. over 20,000ft it was better.

I agree that the Japanese figures/information in western books is a mess and is often copied form old book to old book.
But some of these intelligence estimates may not be correct either.

 

[Snautzer01]

Perhaps of intrest. Ebay: Japanese airplanes and other hardware.

 

[MikeMeech]

I've seen that ~360 mph claim for many years, and in many books too. Twentieth century aviation books copied from one another or from the same not very rigorous sources many times, in the process often repeating myths and tropes with little bearing on reality.

The 410-415 mph estimates seem to be more recent (including on the Wiki page though that means very little). I think this comes from wartime documents, or postwar testing, but I'd love to see more actual sources, all I could find is the link I already posted from WW2aircraftperformance. Which shows the 408 mph / 353 knots at 20,000 ft, and an (also very impressive) speed of 355 mph / 308 knots at sea level. That form looks to me like a postwar US form. I don't know what their source as, though it seems pretty detailed.

Hi
While there can be problems with details in books, especially repeating what has been in other publications without checking (even Professors of History are not free from this vice), we also need to be careful of wartime publications. Your posted document dated March 1945 is problematic as page 2 mentions that:

"A new performance sheet will be issued shortly on GEORGE. Recent findings have made some variations in the above figures."

It would be of interest to see a copy of the revised performance sheet to see what the "variations" were.

Mike

 

[qaz]

Very high speed values for Japanese planes are usually pulled from the TAIC calculations of wartime, and those shouldn't be taken at face value. Usually these planes never actually demonstrated such performance.

However, in terms of Homare/Ha-45, Japanese speed values are often in a de-rated condition.
i.e. the 321kt (594km/h / 369mph) official figure of Shiden Mod 21 is certainly with a de-rated Homare. It was restricted in service.

The realistic top speed is hard to establish for these reasons, it will be somewhat north of 600km/h, but not nearly at the Allied calculation.
I think probably around 620-630km/h based on numbers that are put out in Japanese sources, and relative to Ki-84's performance.

 

[SaparotRob]

Didn't the avgas used in these tests positively affect the performance of the Japanese aircraft?

 

[Wild_Bill_Kelso]

Well I know in some of the tests of A6M types the War Dept was having trouble with fuel or spare parts or something, and were heavily lowballing what we later found out to be the actual performance figures.