Best Japanese B-29 'Killer'

[drgondog]

it starts at what alt?


Kris

Typically at 20-30K but there was no fixed bandwidth.. like currents in the ocean, multiple layers fueled by rapidly changing pressures associated with moving frontal weather systems.. Pacific well noted for the monsters, although 'jet streams' exist everywhere..

 

[Civettone]

thank you !


Kris

 

[Washing Machine Charlie]

I'm looking for the source, but, I remember reading an interview with a Russian MiG-15 pilot stating that the gunners on B-29s were quite good and a definite danger for intercepting Migs..

16 Superfortresses were lost to Mig-15s during the Korean War. Their loss rate was 1 per 1000 sorties...

 

[Washing Machine Charlie]

Thanks!

For the newbies, I have a thread called "All Things B29"

B-29 Engineering Flight book

Lots of interesting info there.

 

[FLYBOYJ]

I'm looking for the source, but, I remember reading an interview with a Russian MiG-15 pilot stating that the gunners on B-29s were quite good and a definite danger for intercepting Migs..

"According to Far East Air Force Bomber Command records, Superfort crewmen were credited with shooting down 33 enemy fighters, 16 of them MiGs. Another 17 MiGs were listed as probably destroyed, with 11 damaged."

https://www.historynet.com/superforts-vs-migs.htm

 

[Kevin J]

Damn and only 80-100 were brought down by fighters in over 10,000 sorties. That sucks if you are Japanese.

Hey, but the end of the war, flying an Il-2 on the Eastern Front, you were likely to survive 93 sorties as opposed to 7 or 8 in the first few months of the war.

 

[CORSNING]

Well for what its worth (since you all reopened the thread), Wikipedia lists
the Ki.61-II as having shot down the majority (a greater number than any
other fighter) of B-29s. .., but the Ki.61-II, when compared to other late
war Japanese fighters, does have one of the best high altitude performances.
Its speed and climbing ability easily exceeded the Ki.100 at very high
altitudes.
We are talking a bomber interceptor, not a 1-on-1 fighter vs. fighter.

 

[Shortround6]

Well for what its worth (since you all reopened the thread), Wikipedia lists
the Ki.61-II as having shot down the majority (a greater number than any
other fighter) of B-29s. .., but the Ki.61-II, when compared to other late
war Japanese fighters, does have one of the best high altitude performances.
Its speed and climbing ability easily exceeded the Ki.100 at very high
altitudes.
We are talking a bomber interceptor, not a 1-on-1 fighter vs. fighter.

1st step in intercepting high flying bomber.................reach the same altitude as the bomber if not higher.

 

[PAT303]

The biggest problem with the Japanese was their technology, or lack thereof. Both the British and German forces in particular had well organised air defence systems from ground observers to low medium and high radar coverage with light medium and heavy AAA to match, not to mention aircraft far ahead of anything the Japanese air forces could field. The fact LeMay stripped the B29's of guns and had them fly at low altitudes speaks volumes of the quality of the japanese home defences.

 

[CORSNING]

1st step in intercepting high flying bomber.................reach the same altitude as the bomber if not higher.

TAIC A/C @ 9,000 m. (29,527 ft.) using 92 octane:
Aircraft: Speed / Climb rate / Combat ceiling (1,000 fpm)/ Armament
Ki.61-II: 417 mph/2280 fpm/37,400 ft./2 x 12.7 mm/200 rpg. + 2 x 20 mm/150 rpg.
Ki.84-1a: 403 mph/1720 fpm/33,755 ft./2 x 12.7 mm/350 rpg. +2 x 20 mm/150 rpg.
N1K2-J: 375 mph/1445 fpm/32,480 ft./ 4 x 20 mm/220 rpg.
J2M3m21: 383 mph/1850 fpm/33,800 ft./4 X 20 mm/200 rpg.
Ki.44-II: 345 mph/1190 fpm/30,715 ft./2 x 12,7 mm/250 rpg/2 x 40 mm.
Ki.45-KAIc: 322 mph/1005 fpm/29,580 ft./1 x 37 mm/16 rds.+2 x 20 mm/1 x 7.92/1000 rds.

There were two major problems with these figures, that I know of. The first was these
figures being reach required good workmanship in manufacturing. The second hurdle
was that 92 octane fuel was required. By the time the B-29 raids began, there
was problems with both. Unskilled labor and tree sap 85 octane fuel.
There was other major problems but they did not have to do with these aircraft reaching
these figures. There just wasn't enough of them and no good early warning system.

I do not have a TAIC report on the Ki.100 but it is safe to say that at altitudes of 30,000 ft.
only military ratings would be used. with that in mind the following figures would be
close.
Ki.100-I: 337 mph/~800 fpm/~28,000 ft./2 x 12.7 mm/250 rpg + 2 x 20 mm/250 rpg.

 

[Ivan1GFP]

Hello Corsning,

I believe the TAIC data for Ki-61-II is VERY suspect.
The actual critical altitude for Ha-140 engine was only 5700 meters and although the interceptors probably had the typical removal of armour plating and other excess weight, I just don't see it making 1000 feet / minute up to 37,000 feet or hitting 417 MPH in level flight under ANY conditions.

One of the biggest problems with intercepting B-29 is simply lack of suitable aircraft because manufacturing numbers were so small and aircraft with the Homare engine seldom gave their design performance.

- Ivan.

 

[CORSNING]

Hi Ivan,
Yes the TAIC performance for the Ki.61-II is suspect, but to the best
of my knowledge it is the best encompassing knowledge out there
on this aircraft. If it helps any, the Tony was one of Japans cleanest
(low drag) designed fighters.
, Jeff

 

[Ivan1GFP]

Hello Corsning,

I actually agree with you about Ki-61 in general. My own belief is that it was a borderline 400 MPH aircraft or at least very close if flown to its limits.

The problem with the Ki-61-II as an interceptor is that there were just too few of them and of course the known unreliable engine.

If the B-29 had continued the high altitude bombing, even the Ki-61-I would have had a lot of issues.
The only Ki-61-I that were armed with 20 mm cannon in any numbers were the -Id which was much heavier than the rest and 400 of the -Ib and -Ic which had MG 151/20. I believe there were a few more armed with 30 mm guns, but very very few.

That was the point I was getting at earlier: The total production run of anything that had a fair chance against B-29s was several hundred at best.

- Ivan.

 

[CORSNING]

Yes Ivan, you are correct. That is exactly what I meant in post 70 when
I said, " There just wasn't enough of them and no good early warning
system. "
Cheers, Jeff

 

[pinsog]

The US Air Force conducted mock interception tests against the B29 at high altitude (above 30,000 feet) and found out even the P38 and P47 had great difficulty in intercepting the B29. Evidently both the P38 and P47 would go into a high speed stall when attempting to turn at high speed when aiming. If the P38 and P47 had great difficulty at that altitude, what chance did any Japanese fighter have?

As far as the Luftwaffe Me262 above 30,000 feet: I know it was fast and had 4 30 mm cannon, but didn't it have engine problems at high altitude? I thought the Me262 engines were best at middle altitudes and high altitudes caused flameouts or something

 

[Ivan1GFP]

The US Air Force conducted mock interception tests against the B29 at high altitude (above 30,000 feet) and found out even the P38 and P47 had great difficulty in intercepting the B29. Evidently both the P38 and P47 would go into a high speed stall when attempting to turn at high speed when aiming. If the P38 and P47 had great difficulty at that altitude, what chance did any Japanese fighter have?

Hello Pinsog,

Sounds to me like this is a different kind of issue. The "high speed" stalls are because the air is a lot less dense and stall speed increases because the wings need to go faster to generate the same lift.
If you have a Japanese fighter with a very light wing loading and low stall speed, its stall speed at high altitude also increases proportionally, but the absolute number isn't quite so high.
As an example:
The stall speed (clean) of a P-47D-25 is 115 MPH according to the manual.
At 30,000 feet, that works out to 188 MPH TAS just flying straight and level.
For a 2 G maneuver, minimum speed becomes 265 MPH.
For a 3 G maneuver, minimum speed becomes 326 MPH.

The Oscar we were discussing elsewhere has a stall speed barely over half that of the Thunderbolt, so its stall speeds at altitude would also be barely over half that of Thunderbolt. The only problem is that it may not have the engine power to get that high and maintain enough speed for an intercept.

- Ivan.

 

[Washing Machine Charlie]

Also, to the B-29 crew's credit, let's not forget that a lot of the time, they didn't have the benefit of large formations, especially flying from Saipan, which could only launch one plane at a time, at a minute or so between..

Little known fact, the B-29 was built with special seats to accommodate the huge brass nuts each crewmen possessed.

The biggest problem with the Japanese was their technology, or lack thereof. Both the British and German forces in particular had well organised air defence systems from ground observers to low medium and high radar coverage with light medium and heavy AAA to match, not to mention aircraft far ahead of anything the Japanese air forces could field. The fact LeMay stripped the B29's of guns and had them fly at low altitudes speaks volumes of the quality of the japanese home defences.

 

[pinsog]

There is also the story of a B29 whose crew bailed out, I believe over Iwo Jima, leaving the B29 on autopilot at low altitude. A P61 Blackwidow was ordered to destroy the B29 as it was considered a hazard I believe to ships in the area. The P61 crew used their entire load of 50 caliber and 20mm cannon to bring down an undefended B29, at low altitude, on autopilot. Imagine trying to fight a B29 above 30,000 feet, 1 on 1, bombs have been dropped, running full power with a crew that is shooting back at you and trying to kill you. No thanks, I'll pass!

 

[pinsog]

Hello Pinsog,

Sounds to me like this is a different kind of issue. The "high speed" stalls are because the air is a lot less dense and stall speed increases because the wings need to go faster to generate the same lift.
If you have a Japanese fighter with a very light wing loading and low stall speed, its stall speed at high altitude also increases proportionally, but the absolute number isn't quite so high.
As an example:
The stall speed (clean) of a P-47D-25 is 115 MPH according to the manual.
At 30,000 feet, that works out to 188 MPH TAS just flying straight and level.
For a 2 G maneuver, minimum speed becomes 265 MPH.
For a 3 G maneuver, minimum speed becomes 326 MPH.

The Oscar we were discussing elsewhere has a stall speed barely over half that of the Thunderbolt, so its stall speeds at altitude would also be barely over half that of Thunderbolt. The only problem is that it may not have the engine power to get that high and maintain enough speed for an intercept.

- Ivan.

Good points, but a thing or 2 to consider:

The P47 could supposedly out turn a 109 at high altitude due to, as I understand it, a larger wing and more power.

Anything that is going to have the speed and firepower required to bring down a B29 above 30,000 feet is going to have a much higher wing loading than a Zero or KI43.

 

[Ivan1GFP]

Good points, but a thing or 2 to consider:

The P47 could supposedly out turn a 109 at high altitude due to, as I understand it, a larger wing and more power.

Anything that is going to have the speed and firepower required to bring down a B29 above 30,000 feet is going to have a much higher wing loading than a Zero or KI43.

Hello Pinsog,

It kinda depends on what you really mean by "high altitude". Just remember, the Me 109 also had a pretty small wing and wasn't a particularly light aircraft in the versions that were likely to encounter a P-47.

It really isn't a matter of just wing loading though that is a good indication of relative stall speeds. It is a matter of stall speed clean and I don't think you will find a single engine Japanese fighter with a stall speed as high as 115 MPH. I was just using Oscar as an example because I had already calculated its stall speed as somewhere below about 68 MPH from earlier discussions.

- Ivan.