IJAF v.s. the B-29

[ShVAK]

Haven't really studied the PTO very much, so I'm curious to hear you folks' opinions on this: Which late-war IJAF fighter had the best chance of successfully intercepting the B-29 Superfortress?

I know that while some of their best fighters like the Ki-84 Hayate, Ki-100 and N1K Shiden managed to achieve some level of parity with the F6F and P-38 (though perhaps not the much faster F4U and P-51D), none of them seemed to do much to stop the B-29 on its high altitude sorties. Was there a type we know of that could do the job or was the Boeing just that unstoppable?

 

[TheMustangRider]

To the conclusion I could arrive (open to scrutiny and corrections of course ) regarding the USAAF strategic bombing campaign against Japan is that the greatest Achilles' heel for the IJAAF was not its late-war fighter designs which were quite capable in terms of performance and armament but the poorly manner in which its assets were deployed to defend the Japanese home islands.

While the LW, aware of the increasingly prowess of the Allied CBO, concentrated its forces to defend the Third Reich; the IJAAF on the other hand kept its forces widely scattered throughout the Asian mainland, the Philippines and the Southwest Pacific and thus confronted the B-29 menace with fewer assets and a smaller impact of what it could have been possible.

Radar capability was IIRC on a much smaller scale and a less developed state of what Germany fielded and suffered heavily once Iwo Jima and Okinawa were taken by US forces.

 

[Shinpachi]

I recommend the Ki-45.
It was a twin-engined powerful IJA fighter.

 

[MikeGazdik]

Shinpachi: Awesome picture!!!

 

[Shinpachi]

Thanks Mike!
My regret is that I can find little time to work on CGI now.
Please enjoy my older work.

 

[GregP]

If you go digging into it, you will find the real reason for such poor performance against the B-29 was the B-29 itself. While the B-29 cruised at about 220 mph, it could also cruise at 31,000 feet. Its top speed was 357 mph and if it arrived at 220 mph and 31,000 feet, it could accelerate and perform a shallow dive at the same time to transit the target area at 340+ mph, very nearly the top speed of most Japanese fighters, and bomb from 20,000 feet or so. Also, the Japanese had a relatively poor detection system which meant the B-29s were fairly near the target before the IJA or IJHN scrambled to intercept.

From ground level, the best Japanese fighters could get to 20,000 feet in about 5.5 – 6.0 minutes or so, but were traveling at best-climb speed when they got there. Best-climb speed was probably about 180 – 200 mph. The target B-29s were in a shallow dive from altitude and were probably traveling at 320 – 340+ mph when the Japanese fighters got to 20,000 feet, and the fighters then had to accelerate from 200 mph or so to 350 mph or so, and had an overtake speed of zero to 10 – 15 mph.

If it took the fighter just 5 minutes to get to altitude AND to accelerate to 360 mph (it really took way longer), then at 340 mph, the B-29 had covered more than 28 miles in that 5 minutes. So successful interception required VERY careful coordination since the speeds were very high, the ability to turn around and catch the B-29 was VERY slight. They'd typically run out of fuel or blow or overheat the engine before catching a B-29 that went past. Therefore, most interceptions were kills on the first firing pass, and these were very infrequent.

Basically, the B-29, when attacking from altitude, could usually simply stay in front of any attacking Japanese fighter force with a small turn and the fighter would need a half hour or so to catch them, IF it could do so at all. If a determined Japanese fighter pilot locked onto a B-29, the B-29 could, if it were aware, simply steepen the dive a bit and accelerate to the top speed of the fighter or beyond and get away easily. The planes that were shot down by fighters over Japan were usually a combination of Japanese fighters that were already airborne and were already at altitude and at speed due to anticipating the attack or fortuitous early warning, and they were positioned so as to have a good attack situation.

The B-29 was that hard to intercept and shoot down! ... at least over Japan with the ocean approach we had.

It might have been different over Europe where the B-29 could not approach at high altitude and enter a shallow dive to accelerate because the Germans could start the intercept from a distance much farther away from the target than any shallow dive would allow for due to radar warning in advance that the Japanese did not usually have. Therefore, the B-29 in Europe would probably be intercepted at 30,000 feet while cruising at 220 - 250 mph, WITH enough advance warning for the Luftwaffe to be at altitude and airspeed for an intercept with knowledge of the probably attack path.

 

[msxyz]

The Ki-44 was quite succesfull in its role as interceptor against b-29. At the beginning it was maligned by the aircrews simply because it did't follow the usual design approach of Japanese fighters. Had it been used by western pilots, trained to fight in planes like the Fw-190 or the Hellcat, it would have gained wider recognition for its qualities.

Also, unlike the Ki-84, N1k or even the J2m, it wasn't plagued by temperamental engines. The ha-109 put up a honest 1500hp output with standard aviation fuel and was a tried and true design.

It was the only japanese fighter experimentally equipped with a 40 mm autocannon, even if this was closer to what we would consider today an automatic grenade launcher due to the slow velocity of the shells fired.

 

[GregP]

The Ki-44 was said to be a real joy to fly by the TSAIC pilots who flew captured units. Seems as though WE liked it better than the Japanese did.

It would be great to return a unit to the air, wouldn't it? Even if you can't find a restorable engine, the engine was of conventional employment, unlike our J2M Raiden with the engine mounted far back and driving the prop via an extension shaft, and you COULD run another type of radial if you could get your hands on an airframe.

 

[msxyz]

The Ki-44 was said to be a real joy to fly by the TSAIC pilots who flew captured units. Seems as though WE liked it better than the Japanese did.

It would be great to return a unit to the air, wouldn't it? Even if you can't find a restorable engine, the engine was of conventional employment, unlike our J2M Raiden with the engine mounted far back and driving the prop via an extension shaft, and you COULD run another type of radial if you could get your hands on an airframe.

unfortunately, not a single airframe survived. Even the engines are rare, the only intact specimen surviving, that I know of, being buried somewhere in a crate at NASM: a shame for an engine with a long career powering two generations of IJAF medium bombers, a torpedo bomber, a transport and even an interceptor.

If someone could build a replica of the airframe, I think any engine with a diameter of less than 50" and weight around 700 kg could be used instead. The original ki-44 used an engine with a single stage turbocharger with critical altitude of 3700m, the ki-44-ii went for a two stage supercharger that pushed the plane to 5000m in less than four minutes when clean... Not bad for a propeller driver airplane!

 

[krieghund]

My friend's dad flew in WW Korea and gave me a B&W photo of a Ki-44 the USAF had placed up as a gate guard. What a Ki-44 was doing in Korea is anyone's guess. Unfortunately that photo is in storage at the moment. So there might be one kicking around in Korea. Can't remember the base's name but it is written on the back with the date. Next time I rotate back I'll try and fetch it out.

 

[krieghund]

delete please duplicate

 

[msxyz]

My friend's dad flew in WW Korea and gave me a B&W photo of a Ki-44 the USAF had placed up as a gate guard. What a Ki-44 was doing in Korea is anyone's guess. Unfortunately that photo is in storage at the moment. So there might be one kicking around in Korea. Can't remember the base's name but it is written on the back with the date. Next time I rotate back I'll try and fetch it out.

Well, Corea was part of the possessions of Japan till '45. Some ki-44s based in Taiwan were used by Chinese indipendentists against Maoists, so the plane career didn't end with ww2.

 

[ColesAircraft]

The Ki-44 would have been a common sight in Korea until scrap drives wiped them out after the war. Both the Japanese Army and Navy moved their training schools to Korea late in the war to be further out of range of American bombers.

A Ki-44 wing was recently put on display by the Chinese, who every now and again pull similar rabbits out of their hat without much explanation as to their origins. I haven't heard of anyone who's been able to get any more information from the Chinese regarding how much more, if anything, they have of the aircraft.

A friend of mine went on an expedition to Manchuria a few years ago, and onward into Mongolia, in search of aircraft like the Ki-44 that might still be uncovered in those areas - but found nothing substantial.

The Ki-44 was indeed a great aircraft, though! Certainly underrated by its pilots for the reasons previously described. Turned like a truck, but had a wicked rate of climb and was everything that the lighter Zeros and 'Oscars' were not.


- R

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[davebender]

B-29 was that hard to intercept and shoot down! ... at least over Japan with the ocean approach we had.

Why didn't Japan employ radar equipped patrol boats 200 miles out from the coast? That would give Japanese interceptors plenty of time to climb to altitude and maneuver to optimum attack position.

 

[RpR]

Was a Ki-44 what a Siamese pilot used to down a B-29?

 

[msxyz]

@ColesAircraft: most account says it turned like a truck but, judging from its wing loading ad the presence of combat flaps it shouldn't have been less maneuverable than any contemporary high performance aircraft. Maybe to the Japanese pilots accustomed to Oscars it seemed a lead sled, but the pilots with less combat experience sent directly to units equipped with Ki-44 didn't encounter any major problem with it. This is a sign that the problem lied in the humans, to stubborn to change their tactics and habits to conform to a machine that required a different approach.

The same, more or less, happened with the J2M in the navy. But the J2M was also plagued by reliability problems and a somewhat rushed design phase which left the aircraft with several minor quirks.

When the Allied finally got their hands on these fine aircrafts, they didn't find anything fundamentally wrong with them; in fact both the Ki-44 and the J2M received positive (sometimes even enthusiastic) reviews from the American test pilots who evaluated them post war.