J2M Raiden combat history

[RotBaron]

Requesting information and sources regarding the combat history of the aircraft.

I've seen a lot of the wiki and wiki-like info/data, of course some of it is useful, but most makes no mention of its' actual performance.

I've been browsing a lot of websites and the like, and Icepac I keep seeing your name in various forums. I've also seen your posts here. Do you have any good sources?

My queries don't yield much...I've tried combinations of "J2M combat history, confirmed kills, and so on...to little avail.

I've found a lot of interesting information and the majority of it hearsay and opinion. Looking for more of "just the facts ma'am" type info. 

However, I found a good write up but the source of such info isn't attributed: http://forums.ubi.com/showthread.php/44161-J2M-Raiden?s=8b64310c1064b3279207d732ac398fc7

Thanks.

Rot

[Karnak]

I can't answer your questions, but this was an interesting thread about the J2M a couple of years ago:

http://bbs.hitechcreations.com/smf/index.php/topic,305660.0.html

I'd love to see it added to AH.

[icepac]

I found it as a relatively unused plane in Warbirds circa about 2005 and it flew like a truck........but a fast truck.

Then they found some sort of mistyped variable in the drag and warbirds did a change of the CoFL around that same time which turned it in an uber champion and probably better than it should have been...........so I stopped flying it.

I'm not sure if they adjusted it since then but it should perform much like a KI44 but with a steeper climb and higher top speed and only slightly less maneuverable........but the maneuverability reputation among japanese pilots was in comparison to the A6M, KI27, and KI43 which were turn champions.

This doesn't mean it couldn't turn.

It had a laminar flow wing but I can't find any airfoil profile that has a naca number that is close.

I'd love to find out the exact profile of the wing because it allowed some pretty good slow turning uncommon with that kind of wing size and aspect ratio.

I preferred the J2M2 which gave a little bit of extra speed at the expense of replacing one 99 type 2 with machine guns which I felt ok since the mixture of 99-1 and 99-2 had different trajectories.

Akamatsu had success with it but there are films of them being shot down but..........I think a pilot with the amount of experience that Akamatsu and a few others had could exploit many of it's traits to thier advantage much like Alexander Pokryshkin was able to do with the mig3.

[RotBaron]

I've been reading a lot on the J2M, what is odd is almost all the websites begin with a nearly identical introduction about the aircraft, yet almost all of them differ on things like speed, climb and even in some cases more structural aspects.

I'm finding it very difficult to find "combat" related information, aside from a handful. There is a lot of information I can't do anything with because it's in Japanese (though.)

I wonder what Mitsubishi's records would be, where to find them or if they desired to keep much from this dark chapter of their history.

Also on the J2M5, I see 43 were built and I see 34 were built. Someone was dyslexic or misheard and many are copying the wrong number there.


Anyone know if there is an account of the oblique firing 20mm landing significant damage? I'm having a hard time imagining anyone wanting to get under a B-29, and in 20mm range to try and open fire with it. That would require at one point flying somewhat level under it and doing some serious multitasking whilst the belly gunner has one focus: the J2M.

This is proving to be a difficult plane to find reliable and verified information about.

[icepac]

Necrobump..........what's wrong with this picture?



Didn't think a single picture was worthy of a new thread so I added it to the collective here.

[MiloMorai]

The American required to pilots to flt the airplane.

[DaveBB]

Back in the 90s during the era of Email Newsgroups, we used to chat with a B-17/B-29 bombardier.  He said the J2M was the only high altitude Japanese aircraft that they encountered on any frequency.  So at least we know it had the speed and high altitude performance to intercept B-29s.

[oboe]

Some data from the TAIC's analysis of a captured Raiden is available here:

http://www.wwiiaircraftperformance.org

They show a top speed in excess of 410 mph, however I think that is disputed because the octane rating of the avgas used by TAIC was higher than what Japan was using.

Still, climb rate > 4600 fpm, top speed in the neighborhood of 400 mph and 4x20mm cannon would make it pretty competitive in the MA.

[Krusty]

Some data from the TAIC's analysis of a captured Raiden is available here:

http://www.wwiiaircraftperformance.org

They show a top speed in excess of 410 mph, however I think that is disputed because the octane rating of the avgas used by TAIC was higher than what Japan was using.

Still, climb rate > 4600 fpm, top speed in the neighborhood of 400 mph and 4x20mm cannon would make it pretty competitive in the MA.

I think you'll find that non-TAIC numbers show it was slower than the Ki-84 we already have and had a much lower FTH as well. It would be around 370mph at 16K.

That would put it about par with our Ki-61, which was woefully obsolete in 1944 when the J2M was starting to show up:



Remember that they had been trying to produce it since 1942 after the Battle of Midway. Setbacks, technical issues with the engine/cowling, bombing factories causing delays etc etc meant that the design didn't roll off the line and into the hands of units until (mostly) Feb 1944. By that time, the N1K2 and the Ki-84, the A6M5b, and other designs were already around. It was too little, too late.

So, it wouldn't be any kind of super plane. It would still be quite the underdog. It would be very cool, though.

[oboe]

If wiki data can be relied on in this case, it should be better than the Ki.61 - much more power but lighter airframe = much better climb rate, slightly lower wing loading and better gun package.   I'm guessing it'd have better rear visibility than the Hien also.

It'd be Japan's fastest climbing interceptor, very well-armed at that.   It;d prolly steal flyers from both the Ki.61 and N1K2 ranks...

[Krusty]

Which wiki numbers? They seem a bit inconsistent. The J2M3, which was really the only real version to consider since nothing after that made it into any real kind of production, had a heavier empty weight than the late-era Ki-61 which we have in-game. Earlier Ki-61s would have been even lighter and more nimble.

The J2M3 also had a very high landing and stall speed, between 100 and 130mph depending on varrying comments I've seen. That means the wings, which had generally the same surface area as the Ki-61, were shorter in span, thicker in chord, but also less efficient in lift. They were high speed wings, not climbing wings.

In general terms, Francillion was noted as saying the N1K was better overall and more maneuverable and had better range and visibility out the back on top of that. TAIC pilot comments indicate the ailerons stiffen up very early even at cruising speeds and rolling is extremely hard as low as even 325mph. The J2M2 didn't even meet the original climb specs of the order, but with the J2M3 it sank further away from that, earning the dislike of pilots for its performance. They appreciated the extra firepower, however, replacing the 2x7mm with 2x20mm, even though they were the older type.

The 4800 fpm climb numbers are from the TAIC captured test which admittedly has much higher performance using better avgas than the Japanese were able to pull off. These are the same folks that got ~430mph out of a Ki-84, remember. Those numbers are also based off the 3-gear-supercharged J2M5 if I recall. Not the actual combat J2M3 version. There were only about 30-something J2M5s built, and those were horribly unreliable per pilot claims. Yet, most numbers you see are so fantastical because they're a perfect-condition TAIC J2M5 with 91+ octane avgas.

They're not realistic numbers, is what I'm getting at.

Would be a nice addition to the game, maybe, but I wouldn't want some fantasy variant that was uber or anything when it was really just kind of "okay" for its time.

[oboe]

Here's specs from the Wikipedia entry for Mitsubishi J2M (https://en.wikipedia.org/wiki/Mitsubishi_J2M#Specifications)

Specifications
Data from Mitsubishi J2M3-21 Raiden
General characteristics
Crew: one, pilot
Length: 9.70 m (32 ft 8 in)
Wingspan: 10.80 m (35 ft 5 in)
Height: 3.81 m (13 ft 0 in)
Wing area: 20 m² (216 ft²)
Empty weight: 2,839 kg (6,259 lb)
Loaded weight: 3,211 kg (7,080 lb)
Powerplant: 1 × Mitsubishi MK4R-A Kasei 23a 14-cylinder two-row radial engine, 1,379 kW (1,850 hp)
Performance
Maximum speed: 596km/h （370 mph, 322kt） (@5450m)
Range: 560 km (302 nmi, 348 mi)
Service ceiling: 11,430 m (37,500 ft)
Rate of climb: 1402 m/min (4,600 ft/min)
Wing loading: 174 kg/m² (35 lb/ft²)
Power/mass: 0.42 kW/kg (0.26 hp/lb)

And for the Ki.61:  https://en.wikipedia.org/wiki/Kawasaki_Ki-61#Specifications_.28Ki-61-I-KAIc.29
Specifications (Ki-61-I-KAIc)
Data from Japanese Aircraft of the Pacific War
General characteristics
Crew: 1
Length: 8.94 m (29 ft 4 in)
Wingspan: 12 m (39 ft 4 in)
Height: 3.7 m (12 ft 2 in)
Wing area: 20 m2 (220 sq ft)
Airfoil: NACA 2R 16 wing root, NACA 24009 tip
Empty weight: 2,630 kg (5,798 lb)
Gross weight: 3,470 kg (7,650 lb)
Fuel capacity:
Internal 550 l (150 US gal; 120 imp gal)
External 2x 200 l (53 US gal; 44 imp gal)
Powerplant: 1 × Kawasaki Ha40 inverted liquid-cooled V-12 piston engine, 864 kW (1,159 hp)
Propellers: 3-bladed variable pitch propeller
Performance
Maximum speed: 580 km/h (360 mph; 313 kn) at 5,000 m (16,000 ft)
Range: 580 km (360 mi; 313 nmi)
Service ceiling: 11,600 m (38,100 ft)
Rate of climb: 15.2 m/s (2,990 ft/min)
Time to altitude: 7.0 min to 5,000 m (16,000 ft)
Wing loading: 173.5 kg/m2 (35.5 lb/sq ft)
Power/mass: 0.25 kW/kg (0.15 hp/lb)

I think that's our Ki.61, and it apparently sourced from Francillon.  Not sure about the J2M3 specs

[oboe]

I followed a reference in the wiki J2M article and its from a TAIC document.  Odd though, the text lists top speed as 370 mph, which is inconsistent with what I thought we know about the TAIC numbers - but the TAIC document referenced lists the top speed @ 407mph.   So I take your point about inconsistency in the data.

Either way, the requirements for a successful interceptor should be a fast climb and hard hitting gun package - which I think the J2M3 possesses.   1850 hp engine on a 7,080 lb (loaded) airframe indicates to me it should climb very well, and 4600 fpm seems reasonable.  If the 4600 fpm number is dubious due to TAIC testing with higher octane gas, even if you knock down the climb rate by the same percentage as the speed discrepancy, you still get 4100+ fpm, which is still pretty dang good.   Disappointed to learn about the pilot comments regarding low roll rate at high speed though.

[AAIK]

Even if you knock down the climb rate by the same percentage as the speed discrepancy, you still get 4100+ fpm, which is still pretty dang good.

Agreed! I was just thinking about how good it would be in that respect; *drool*!

[icepac]

LOL.....many of you still don't understand that simply putting higher octane gas in a plane designed for low octane gas will do nothing to improve the performance.

That only works on cars that have knock sensors in their digital fuel injection systems.

Didn't any of you read the recent thread about this?