Thoughts on the Nakajima Ki-84 and Kawasaki Ki-100

[GregP]

Thanks MiTasol!

The Horsemen was / is Steve Hinton Sr.

Steve Hinton Jr. could fly with them anytime he or they wanted him to, but it takes some time commitment that he might have trouble with ... and might not. I'm not too sure when the Horsemen last flew at this time. Probably pre-pandemic. There haven't been many airshows for awhile.

 

[DarrenW]

I'm always left shaking my head when I see the horsepower ratings of Japanese engines. Does anyone know of a reference dealing primarily/solely with Japanese aircraft engines?

Here's a thread which has some details you are looking for. The TAIC manuals are historically significant but I'm not sure how accurate they are.

Japanese engine manuals and technical drawings (blueprints)

Following a link provided by Shinpachi to the Japanese archives I found a number of Japanese engine and aircraft manuals so I will post all here by providing links as this is a site that should never disappear. The basic link is http://dl.ndl.go.jp/info:ndljp/pid/ (If that link does not work...

ww2aircraft.net

 

[BlackSheep]

NAA sure built pretty airplanes.

Isn't that the truth? I've read several pilot's accounts stating that Sabres were a pleasure to fly, even now.

 

[DarrenW]

An F4U-4 comes in at 9,200 lbs empty and 14,670 lbs gross. It has 314 square feet of wing area. The engine has 2,380 hp WER. That is 6.16 lbs/hp.

A Ki-84 I-a comes in at 5,864 lbs empty and 7,940 lbs gross. It has 230 square feet of wing area. The engine has 2,041 hp at sea level. That is 3.89 lbs/hp. It also has 3 feet more wingspan than a Corsair. It SHOULD be a bit better at higher altitude due to better span loading.

Just a few corrections here: the COMBAT weight of the F4U-4 was 12,405 lbs, which would lower the weight to power ratio (5.21 vs 6.16 lbs/hp). And we must remember that HA-45-21 was de-rated to 1800 hp early on so this increased the ratio to 4.41 lbs/hp. Even so, this rating too was difficult to reach by operational aircraft given the state of the JAAF during 1944-45.

Secondly, the Corsair actually had four more feet of wingspan than the Hayate (41 vs 37 feet). Better at higher altitude? I highly doubt this, as the Homare engine didn't run all that much boost even at maximum settings and it didn't have enough supercharger (single stage) to really compete.

 

[GregP]

I'm just going by reported spans for the models I looked up. I also doubt seriously that a 2,000 hp engine would be accepted for flight if it only out out 1,800 hp. You'd notice it in the way it ran. Perhaps they never used the full military power setting at rated manifold pressure and rpm?

The Allies had a LOT of disparaging things to say about the A6M5 Model 52 Zero but, having seen one running very close up, having seen it through a major overhaul, and having worked on it, I can tell you it was as well-built in general as any other warbird I have seen flying, and that takes in a LOT of warbirds. So, my doubting Thomas hat in on and running when people run down Japanese airplanes in general. I've also seen the J2M Raiden up close and personal, and it, too, is quite well-built. If these two aircraft and the only Betty bomber (crashed but recovered)I've ever seen are anything to go by, then Japanese aircraft were very nicely built devices indeed.

The Planes of Fame Zero was the one flown in the 1944 Fighter Conference and, if you go check it out, It was the ONLY fighter out of some 29 - 30 airplanes that ran the entire time with no maintenance glitches. This is noted several times in the report. Again, I doubt the truth of claims about bad-running engines after have experienced several live and in person.

 

[DarrenW]

I also doubt seriously that a 2,000 hp engine would be accepted for flight if it only out out 1,800 hp. You'd notice it in the way it ran. Perhap

The HA-45-21 was known to have cooling issues. It ran at a greater rpm and compression ratio than other high-power radials of the day and keeping the back row of cylinders at safe operating temperatures for more than just a short period of time was problematic. Being comparatively small by standards of the day (and very compact) overheating can be expected hence the derating. I'm sure lower than expected octane fuel played a role as well.

So, my doubting Thomas hat in on and running when people run down Japanese airplanes in general.

Stating well established facts about an aircraft doesn't equate to "running it down." Are you saying that, unlike the Germans, the Japanese weren't experiencing both manpower and raw material shortages late in the war? And even though quality may be satisfactory in a number of areas there could still be certain aspects of an airplane which suffers and thus affect it's performance.

The Planes of Fame Zero was the one flown in the 1944 Fighter Conference and, if you go check it out, It was the ONLY fighter out of some 34 - 35 airplanes that ran the entire time with no maintenance glitches

Interesting. I don't doubt your claim but without knowing the total flight hours of each aircraft present it's very hard to make an apples-to-apples comparison of reliability during the conference. Do you happen to have this data per chance?

 

[GregP]

It may or may not be in the minutes of the Fighter Conference, but I remember that aircraft flown were selected from relatively good-condition, relatively low-time stateside units. If I recall correctly, they put a total of about 160 hours on the A6M-5 during the conference. The Report of the Joint Fighter Conference is NOT very well indexed and finding something you read a few years back is problematic, to say the least, without extensive re-reading.

But, the Allied planes flown for the conference were NOT "war weary" units by any means.

I came away VERY impressed with the reliability of the A6M-5 they flew and, after seeing it in person and working on it, I am even more impressed. It isn't "better than ours," so to speak, but it also isn't worse in workmanship. The build quality, if you will, is pretty good but not outstandingly better or worse than other fighters. Looks pretty typical to me, workmanship-wise.

 

[SaparotRob]

Hey GregP, how original is the J2M you mentioned above?

 

[GregP]

The J2M is VERY original. It COULD be restored to flight status, but the Planes of Fame has a policy of not flying airplanes for which they don't have a spare engine. The engine in the J2M is a Mitsubishi MK4R-A Kasei, but it not a "normal" Kasei. The Kasei in the Raiden has a LONG driveshaft and the likelihood of finding a spare is about nothing. See the pic below ... the exhaust collector is short and is near the rear cylinders, so you can see that it has a long prop shaft on it.

So, while it COULD be restored to flight status, there are no current planes to do so as far as I know at this time. The aircraft as it is now has modern tires on it of the correct size, but almost everything else is original as-built. It is an impressive machine and is NOT a small airplane ... it is much bigger than the Zero.

Altogether a nice-looking fighter.

 

[BiffF15]

The J2M is VERY original. It COULD be restored to flight status, but the Planes of Fame has a policy of not flying airplanes for which they don't have a spare engine. The engine in the J2M is a Mitsubishi MK4R-A Kasei, but it not a "normal" Kasei. The Kasei in the Raiden has a LONG driveshaft and the likelihood of finding a spare is about nothing. See the pic below ... the exhaust collector is short and is near the rear cylinders, so you can see that it has a long prop shaft on it.

So, while it COULD be restored to flight status, there are no current planes to do so as far as I know at this time. The aircraft as it is now has modern tires on it of the correct size, but almost everything else is original as-built. It is an impressive machine and is NOT a small airplane ... it is much bigger than the Zero.


View attachment 656861

Altogether a nice-looking fighter.

Greg,

Do you guys have any history on your J2M?

Cheers,
Biff

 

[SaparotRob]

Darthtabby

Perhaps this will help?


Eagledad

Thanks for that post. Very interesting read. I liked the line "plane will not stall in this configuration".

 

[BlackSheep]

Most of the WWII sims are just games. They have very little to do with reality. It's been a LONG while but, as I recall in Il-2, the aircraft almost always crash if you land them off-airfield. In reality, real WWII airfields were just off-airport fields and many were quite rough.

Perhaps I misremember ...

I am just barely old enough to have seen some of the auxiliary fields surrounding Luke AFB, Arizona leftover from WW2 and you are correct, most could have and probably did double for fair,festival, flea market sites and parking. One, I believe was even turned into a dirt race track , when Maricopa County Sheriffs were looking the other way, that is. Alas, housing developments have taken over these sites.

 

[GregP]

Greg,

Do you guys have any history on your J2M?

Cheers,
Biff

It was manufactured in Nagoya, Japan and was delivered in March 1944. It was the 14th J2M3 produced at Mitsubishi Airframe Works No. 1, and eventually served with the 302nd Kokutai (Squadron) at Atsugi Aerodrome in Japan. Following the Japanese surrender in Sep 1945, it was sent to the U.S.A. for performance tests. It was later acquired by the Frank Wiggins Trade School in Los Angeles as an instructional airframe. By 1952, the aircraft was an attraction at Travel Town in Griffith Park, California. It was donated to the Planes of Fame Museum (then called simply "The Air Museum") by the Los Angeles Recreation and Parks Department.

It is the sole J2M survivor and, as stated above, is a J2M3 variant.

The Planes of Fame does a very good job of maintaining authenticity, as they do with many things, and the aircraft is painted as it was when it was captured, as is the A6M5 Model 52 Zero.

 

[GregP]

I am just barely old enough to have seen some of the auxiliary fields surrounding Luke AFB, Arizona leftover from WW2 and you are correct, most could have and probably did double for fair,festival, flea market sites and parking. One, I believe was even turned into a dirt race track , when Maricopa County Sheriffs were looking the other way, that is. Alas, housing developments have taken over these sites.

I lived in the Phoenix area for 23 years and am very familiar with the old airports and airparks around there. I got my pilot's license out of Scottsdale airport and flew into most of the airports around Phoenix and the surrounding area, including a few private dirt strips. In our club, we weren't supposed to land "off airport," but I figured a private dirt strip WAS an airport. I didn't land anywhere that wasn't a designated airstrip. Later, they changed that to "off pavement," and I didn't do that anymore, but DID land on old Route 66 (it is paved) at an old ghost town in Northern Arizona. We were there for an hour or so just looking around and didn't see even one car.

I didn't have to worry about density altitude since Route 66 is MUCH longer than any runway at an airport. It was warm and we took awhile to get airborne in a C-172 with 3 of us aboard. We landed at Sedona on the way home for lunch.

 

[BlackSheep]

I lived in the Phoenix area for 23 years and am very familiar with the old airports and airparks around there. I got my pilot's license out of Scottsdale airport and flew into most of the airports around Phoenix and the surrounding area, including a few private dirt strips. In our club, we weren't supposed to land "off airport," but I figured a private dirt strip WAS an airport. I didn't land anywhere that wasn't a designated airstrip. Later, they changed that to "off pavement," and I didn't do that anymore, but DID land on old Route 66 (it is paved) at an old ghost town in Northern Arizona. We were there for an hour or so just looking around and didn't see even one car.

I didn't have to worry about density altitude since Route 66 is MUCH longer than any runway at an airport. It was warm and we took awhile to get airborne in a C-172 with 3 of us aboard. We landed at Sedona on the way home for lunch.

The strips I am referring to were around the northern end of the White Tank Mountains, west of Luke AFB (my place of birth, cost my dad 35 cents! Lol), if you remember the area. Once, when exploring the hills, I found the remains of what I can only imagine was a target glider. It had some aluminum framework and a wing of honeycombed material.
In the '60s and '70s, there was a C-47/DC-3 parked in the middle of a large farm with a dirt strip. It belonged to some end of the world group/survivalists and was supposedly packed and ready to flee Phoenix should the missiles be on the way. Puts preppers bug out suvs to shame, lol.

 

[GregP]

I used to ride trials motorcycles in and around White Tanks and am quite familiar with the area. There are still a few places where you can see the old airstrips from the air, but I'd not want to land MY airplane there. You might buy a prop getting out when you land and look at the nicks caused from gravel and other FOD. Nobody has done a FOD walk since WWII!

 

[BlackSheep]

I used to ride trials motorcycles in and around White Tanks and am quite familiar with the area. There are still a few places where you can see the old airstrips from the air, but I'd not want to land MY airplane there. You might buy a prop getting out when you land and look at the nicks caused from gravel and other FOD. Nobody has done a FOD walk since WWII!

I believe it was at a strip called Luke auxiliary #5 near Bell rd and Grand Ave, I was walking around and found an awesome brass (?) compass under a tree, it was in perfect shape for something that had probably been there for decades. The old parking fields for Luke Days were a metal detectors heaven. Lol .. I even found a Browning Hi-Power there, but, someone had kicked it out of their car when parking and considering Airforce security was about 10 yards away, I didn't want any part of having a gun on base.

 

[spicmart]

The J2M is VERY original. It COULD be restored to flight status, but the Planes of Fame has a policy of not flying airplanes for which they don't have a spare engine. The engine in the J2M is a Mitsubishi MK4R-A Kasei, but it not a "normal" Kasei. The Kasei in the Raiden has a LONG driveshaft and the likelihood of finding a spare is about nothing. See the pic below ... the exhaust collector is short and is near the rear cylinders, so you can see that it has a long prop shaft on it.

So, while it COULD be restored to flight status, there are no current planes to do so as far as I know at this time. The aircraft as it is now has modern tires on it of the correct size, but almost everything else is original as-built. It is an impressive machine and is NOT a small airplane ... it is much bigger than the Zero.


View attachment 656861

Altogether a nice-looking fighter.

The Raiden fuselage had a diameter about 20 cm bigger than the Zero'S, yet it is said to have been more aerodynamic than the Zero, afaik.

 

[GregP]

The Raiden fuselage is MUCH bigger than 20 cm larger than a Zero's fuselage. The cockpit of the Raiden is larger than even the cockpit of a P-47 razorback! You can take evasive action by jumping around inside it.

The A6M has a span of 36 ft. 1 in. with 241.5 sq. ft. of wing area. Length is 29 ft 11 in. Gross weight is 6,047 lbs. Empty weight is 4,175 lbs.

The J2M has a span of 35 ft. 5 in. with 215.8 sq. ft. of wing area. Length is 32 ft. 8 in. Gross weight is 7,079 lbs. Empty weight is 6,259 lbs.

So, the J2M, with a slightly smaller wing, is longer than the Zero and comes in more than a ton heavier in empty weight. That weight doesn't come from being smaller overall than a Zero. If you see than side by side (I have, several times), the J2M jumps out at you as larger and a cursory look at the cockpits will make the J2M's cockpit seem twice a big and the Zero's.

You can EASILY get inside a J2M. Not so, the A6M.

 

[spicmart]

The Raiden fuselage is MUCH bigger than 20 cm larger than a Zero's fuselage. The cockpit of the Raiden is larger than even the cockpit of a P-47 razorback! You can take evasive action by jumping around inside it.

The A6M has a span of 36 ft. 1 in. with 241.5 sq. ft. of wing area. Length is 29 ft 11 in. Gross weight is 6,047 lbs. Empty weight is 4,175 lbs.

The J2M has a span of 35 ft. 5 in. with 215.8 sq. ft. of wing area. Length is 32 ft. 8 in. Gross weight is 7,079 lbs. Empty weight is 6,259 lbs.

So, the J2M, with a slightly smaller wing, is longer than the Zero and comes in more than a ton heavier in empty weight. That weight doesn't come from being smaller overall than a Zero. If you see than side by side (I have, several times), the J2M jumps out at you as larger and a cursory look at the cockpits will make the J2M's cockpit seem twice a big and the Zero's.

You can EASILY get inside a J2M. Not so, the A6M.

Sorry, not sure but it could be the engines which has 20 cm diference in diameter...
You know why they made the cockpits so large? I mean the average Japanese pilot was smaller than their Allied counterparts.