TA-152 vs B-29 (1 Viewer)

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The 8th AF had enough trouble hitting the target from 20,000 feet. The higher you go the less accurate the bombing. Lemay went to night operations at 7000 feet precisely to get more bombs on target.
 
Are you referring to the bombing campaign of Japan?
A very poorly worded post on my part. The 8th AF had problems getting bombs on target in Germany. As the attached paper notes accuracy dropped off significantly with attitude. This , coupled with the fact that USAAF's bombing accuracy from 30,000 feet over Japan was a major reason for switching to night bombing at lower altitudes, I am questioning whether B-29s or B-32s would actually fly at 30,000 feet or would they fly at an altitude that minimized the effectiveness of flak similar to the attitudes B-17s flew. Also note that flying at high altitudes reduced bomb loads.

Altitude vs Accuracy 2.JPG


Altitude vs Accuracy.JPG


The paper spends a lot of time discussing the advantages of the British Mk XIV sight under certain conditions. I'm sure the heretic who wrote that enjoyed his next posting measuring air temperatures in the north of Greenland.

Some will claim that the B-29 was a more accurate bomber due to superior radar but this report posted on another website shows that in 1949 B-29s bombing from 25,000 feet without enemy opposition and with better trained crews were still not very accurate. See Chart 9.
 

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  • 8th AF Bombing Accuracy Sept to Dec 1944.pdf
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I have often wondered why, if the B-29 was the magical system it was purported to be, the USAAF bombed from 30,000 feet and even more puzzling is why they switched to night bombing if they had nothing to fear from Japanese day fighters. Japanese flak was nowhere near as effect as German flak. In particular they lacked an effect medium range weapon similar to the Bofors (this is why they could in so low at night). Why not just come in at 9,000 feet. The bombing accuracy would be dramatically improved, the bomb loads would increase and since shooting down Japanese fighters was like swatting flies the remaining Japanese fighter and their pilots would be destroyed in short order. If 9,000 feet was considered too risky from flak the standard and pretty much only Japanese AA gun was only 75mm and posed no real threat to aircraft flying at 20,000 feet.

Japanese Antiaircraft Fire, WWII Tactical and Technical Trends, No. 42, January 13, 1944 (Lone Sentry)

The answer is that the system was nowhere near as effective as claimed. From US Air Force Historical Study No 6 "The Development of the Heavy Bomber 1918-1944"

B-29 Defense.JPG


A few excerpts from the attached paper amplify the point:



B-29 Self Defense 1.JPG

B-29 Self Defense 2.JPG


B-29 Self Defense 3.JPG
 

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  • Test of GE Fire Control B-29.pdf
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The switch to night bombing had nothing to do with high altitude daylight bombing (which was not discontinued), it was specifically for incendiary bombing, which was conducted most often at 5,000 feet.
The factors involved in the decision was that Japan's night fighter force was almost non-existant as well as their AA batteries being ineffective at night.
Additionally, the M69 incendiary bomb was not a high altitude weapon. It needed to be dropped at lower altitudes in order to maximize saturation of a target.
 
The switch to night bombing had nothing to do with high altitude daylight bombing (which was not discontinued), it was specifically for incendiary bombing, which was conducted most often at 5,000 feet.
The factors involved in the decision was that Japan's night fighter force was almost non-existant as well as their AA batteries being ineffective at night.
Additionally, the M69 incendiary bomb was not a high altitude weapon. It needed to be dropped at lower altitudes in order to maximize saturation of a target.

And on top of all that, LeMay had most of the defensive armament stripped in order to save weight, for more ordnance iirc.
 
I have often wondered why, if the B-29 was the magical system it was purported to be, the USAAF bombed from 30,000 feet and even more puzzling is why they switched to night bombing if they had nothing to fear from Japanese day fighters. Japanese flak was nowhere near as effect as German flak. In particular they lacked an effect medium range weapon similar to the Bofors (this is why they could in so low at night). Why not just come in at 9,000 feet. The bombing accuracy would be dramatically improved, the bomb loads would increase and since shooting down Japanese fighters was like swatting flies the remaining Japanese fighter and their pilots would be destroyed in short order. If 9,000 feet was considered too risky from flak the standard and pretty much only Japanese AA gun was only 75mm and posed no real threat to aircraft flying at 20,000 feet.

Japanese Antiaircraft Fire, WWII Tactical and Technical Trends, No. 42, January 13, 1944 (Lone Sentry)

The answer is that the system was nowhere near as effective as claimed. From US Air Force Historical Study No 6 "The Development of the Heavy Bomber 1918-1944"

View attachment 641980

A few excerpts from the attached paper amplify the point:



View attachment 641981
View attachment 641983

View attachment 641984
Interesting information but a few things to consider -

IIRC these tests were conducted out of Florida by "Test Personnel" as the aircraft was becoming operational. I don't think any crew who actually saw combat with the B-29 were actually engaged in these test.

As far as bombing accuracy over Japan - nothing is mentioned abut the jet stream which was discovered by B-29 crews during their first high altitude missions over Japan. It's a "would have, should have, could have to speculate how the B-29 or B-32 "would have" performed over Germany with out dealing with the Jet Stream or having not to fly the distances they did in the Pacific.
 
Interesting information but a few things to consider -

IIRC these tests were conducted out of Florida by "Test Personnel" as the aircraft was becoming operational. I don't think any crew who actually saw combat with the B-29 were actually engaged in these test.

As far as bombing accuracy over Japan - nothing is mentioned abut the jet stream which was discovered by B-29 crews during their first high altitude missions over Japan. It's a "would have, should have, could have to speculate how the B-29 or B-32 "would have" performed over Germany with out dealing with the Jet Stream or having not to fly the distances they did in the Pacific.
This whole thread is a "would have", I'm just presenting a less optimistic view. I don't agree with the implication that "Test Personnel" opinions are rubbish. I also don't see why a B-29 bombing Germany from 30,000 feet is going to be more accurate than a B-17 bombing from 24,000 feet.
For the sake of completeness I am attaching the main report that fire control document was a part of.
 

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  • Operational Suitablity of B-29.pdf
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This whole thread is a "would have", I'm just presenting a less optimistic view. I don't agree with the implication that "Test Personnel" opinions are rubbish. I also don't see why a B-29 bombing Germany from 30,000 feet is going to be more accurate than a B-17 bombing from 24,000 feet.
For the sake of completeness I am attaching the main report that fire control document was a part of.
I never said this report was "rubbish" just stating that these tests were done with great criticism of the B-29 and in the end it's combat record dispelled many of these issues. I've seen this document before and again no input from those who flew the aircraft in combat from what I can see.

As far as accuracy between 24 and 30,000 feet? No jet stream and you're carrying almost 3x the bomb load. I think an extra 6,000' wasn't going to make much of a difference.
 
I'm just presenting a less optimistic view. I don't agree with the implication that "Test Personnel" opinions are rubbish.
Not rubbish, just not informed with combat experience with the system. If those tests were accomplished stateside as the plane was going into service, the "test personnel" were most likely not combat experienced gunners, and certainly not with combat experience on the system.
Before the advent of reliable target drones with fighter-like performance, a true airborne workout of the system would be hard to achieve. Culver Cadets are not quite the thing.
 
Mathematically your ??% zone (50% or 75% or whatever metric is being used) you go up with the square of the distance. Like 30,000 is 25% larger than 24,000 so the zone will be 56% larger in area.
This is minimum increase much like a rifle that shoots a 3 in group at 200yds should shoot a 3.75in diameter group at 250yds.
the area of the group is now 11.04 sq in instead of 7.07 sq in.

This also takes no account of wind or other outside factors.

Can the bomber actually hit a particular building from that height or is the bomber putting a number of bombs into an area on the theory that a building of a certain size will occupy a certain percentage of the target area and thus the bomber should stand a reasonable chance of getting a hit if enough bombs are dropped?
 
I never said this report was "rubbish" just stating that these tests were done with great criticism of the B-29 and in the end it's combat record dispelled many of these issues. I've seen this document before and again no input from those who flew the aircraft in combat from what I can see.

As far as accuracy between 24 and 30,000 feet? No jet stream and you're carrying almost 3x the bomb load. I think an extra 6,000' wasn't going to make much of a difference.
In other words the B-29's loss in accuracy due to higher altitude is made up by bigger bomb loads. I say why not be even more effective a by flying lower thereby increasing effectiveness. If the GE fire control system works as advertised it just means the Luftwaffe gets shot down quicker.
 
In other words the B-29's loss in accuracy due to higher altitude is made up by bigger bomb loads. I say why not be even more effective a by flying lower thereby increasing effectiveness. If the GE fire control system works as advertised it just means the Luftwaffe gets shot down quicker.
I can agree with that.

I don't know how accurate this is but...

"According to the Army Air Forces Statistical Digest published in December 1945, in the 13-month period from August 1944 to the war's end in August 1945, B-29s were responsible for the destruction of 914 enemy aircraft in the air with a loss of just 72 of their own to enemy aircraft during more than 31,000 combat sorties flown."

 
Can the bomber actually hit a particular building from that height or is the bomber putting a number of bombs into an area on the theory that a building of a certain size will occupy a certain percentage of the target area and thus the bomber should stand a reasonable chance of getting a hit if enough bombs are dropped?

No bomber of the era could reliably aim at one building and hit it from 30k without massive formations and mass amounts of bombs, right. Pardon the pun, but that's precisely why 1000-bomber raids were mounted -- to ensure hitting and hopefully drenching the target with HE.

I understand and agree with your point that more altitude equals less accuracy (in that era), but putting the point across with this question smacks of moving the goalposts. No one in that era or in this discussion would have made the claim that is the implicit premise of your question.
 
My apologies, the question was more rhetorical.

perhaps this is a better phrase

"or are the bombers putting a number of bombs into an area on the theory that a building of a certain size will occupy a certain percentage of the target area and thus the bombers should stand a reasonable chance of getting a hit if enough bombs are dropped"

Basic point was that a 25% increase in altitude could make for a lot less "accuracy" just from a ballistic/trajectory stand point let alone other influences.

One being how well can the bombardier see through the bombsight? One website says the Norden bombsight used a 20 X telescope. true?
In any case the ability to detect an error in aim through a 20 X sight at 8,000 yds or 10,000yds distance might not be that good?
Same visual displacement of the cross hairs from dead center means a 25% greater miss distance.

This is assuming perfect visibility. a very big assumption.
 
My apologies, the question was more rhetorical.

perhaps this is a better phrase

"or are the bombers putting a number of bombs into an area on the theory that a building of a certain size will occupy a certain percentage of the target area and thus the bombers should stand a reasonable chance of getting a hit if enough bombs are dropped"

Basic point was that a 25% increase in altitude could make for a lot less "accuracy" just from a ballistic/trajectory stand point let alone other influences.

One being how well can the bombardier see through the bombsight? One website says the Norden bombsight used a 20 X telescope. true?
In any case the ability to detect an error in aim through a 20 X sight at 8,000 yds or 10,000yds distance might not be that good?
Same visual displacement of the cross hairs from dead center means a 25% greater miss distance.

This is assuming perfect visibility. a very big assumption.

Sure. Like I say, I get your basic point and agree that it's valid: more altitude equals worse dispersion. And there's also the European weather which was bad enough at 24k.

But even given what -17s, -24s, and Lancs did historically, I can't imagine -29s would do worse, sloppy aiming and all. It's carrying 3-5 times the bomb loadout of the American predecessors, and 50% more than the Lanc, and with better defensive armament than any of 'em.
 
And on top of all that, LeMay had most of the defensive armament stripped in order to save weight, for more ordnance iirc.
In re-reading my uncles diary, (he was with the 315th on Guam) yes, his plane, and all the others in the wing had only the tail guns that utilized a radar system, the gunner only kept the weapons functioning and loaded, the system did all the work. If the radar sensed an aircraft behind the B-29, it tracked and opened fire, not sure if it had the ability to read friendly IFF, one of you better versed in WWII airborne radar systems might be able to answer that.

I also don't see any day missions listed but I do see references to night attacks on heavily defended targets from the mid 20k range in altitude. I'll double check that as it seems kinda' high for what I've ever read about the nighttime Empire missions.

Also he only mentions bombing by radar, never says anything about visual bombsite usage on his missions.
 
In re-reading my uncles diary, (he was with the 315th on Guam) yes, his plane, and all the others in the wing had only the tail guns that utilized a radar system, the gunner only kept the weapons functioning and loaded, the system did all the work. If the radar sensed an aircraft behind the B-29, it tracked and opened fire, not sure if it had the ability to read friendly IFF, one of you better versed in WWII airborne radar systems might be able to answer that.

I also don't see any day missions listed but I do see references to night attacks on heavily defended targets from the mid 20k range in altitude. I'll double check that as it seems kinda' high for what I've ever read about the nighttime Empire missions.

Also he only mentions bombing by radar, never says anything about visual bombsite usage on his missions.
My Uncle Bill was a radio operator in RB-29s and RB-50s during and after the Korean War, I later discovered he flew ferret missions over the Soviet Union during the 1950s. He described the same thing but also talked about a turret with radar sighting but over the years I found no evidence of this and think he was confused with the radar system in the tail. He did say that it was very difficult for the gunners to track fast moving aircraft with the optical system, I don't know if there were improvements on the B-50 fire control system or if the same issues were encountered with the turrets on the B-36. I posted this pic before, I believe this was taken at Barksdale and he was on his way to Japan to replace a crew that was shot down close to Vladivostok.
 

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Not rubbish, just not informed with combat experience with the system. If those tests were accomplished stateside as the plane was going into service, the "test personnel" were most likely not combat experienced gunners, and certainly not with combat experience on the system.
Before the advent of reliable target drones with fighter-like performance, a true airborne workout of the system would be hard to achieve. Culver Cadets are not quite the thing.
By the time that the B-29 was in use, Culver Cadet derived PQ-8 should have all been replaced by the higher performance PQ-14. A PQ-14 was dive tested and broke up at over 400 mph. I always wondered if they were dived to high speed for gunnery training. The B-29 program was important enough that it should have merited use of Bell RP-63 targets. The P-63 was the follow-up to the P-39 which I've read somewhere on a forum was the best fighter of WWII.
 

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