8th AF bombing
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buffnut453
Captain
Short answer...they didn't. Most bombers in the formation didn't even have bomb sights; they simply dropped when the lead ship dropped. Typically, only the lead ship plus a certain number of alternates (in case the lead aborted/was shot down) carried the Norden bomb sight.
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buffnut453
Captain
They didn't. The bombs fell over a much wider area, despite the claims of "precision" bombing. Dispersion in the bomb fall alone will result in a spread of effects outside the target area. Adding the physical footprint of the aircraft box formation etc, simply increases the problem.
fubar57
General
A nice site to play around in.... Research | 8th Air Force Historical Society
Thumpalumpacus
Major
... and that's why we call it "carpet-bombing" nowadays.
33k in the air
Staff Sergeant
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I'm sure they would have loved to have had laser- or GPS-guided bombs. Alas, that technology lay decades in the future.
fubar57
General
Need this....
Thumpalumpacus
Major
They had no choice but to play the odds.
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Staff Sergeant
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Prof. Farnsworth: "So many loves half-loved, so many inventions half-invented. Why, that damn time machine alone set me back fifteen years!"
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Accuracy obviously cant be any more accurate than the area of the bomber box, As far as I remember from posts here accuracy was improved when the plane was "slaved" to the bombardier /Norden sight and deteriorated with each successive "box" A fourth box if there was one may as well have been bombing through cloud or at night, by the time it arrived the target was covered in dust and smoke.
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Barrett
Senior Airman
Correct, and then some.
The AAF standard of bombing accuracy was Circular Error Probable (CEP) measuring the percentage of bombs dropped on a particular target striking with 1,000 feet radius of the aim point. It was rarely achieved.
The AAF standard of bombing accuracy was Circular Error Probable (CEP) measuring the percentage of bombs dropped on a particular target striking with 1,000 feet radius of the aim point. It was rarely achieved.
drgondog
Major
All true but the question 'what could, and frequently be achieved' also had many successes when target MPI designated aiming point was visible to the lead bombardier.
Recognizing that machine shops/tooling or catalytic cracking locations, etc. were on a frequent 'want to take out' list, that 10% CEP may include 10 hits from 150 B-17s very tightly located on the specific target. Also note that at say, Landsberg where a Me factory lay, not only a very large plant existed but a whole lot of 'producution' were on the airfield making a wonderful target on the periphery of the CEP.
Another factor in the ETO totals and averages - weather, undercast - Mickey Nav and bomb aiming was not as good as RAF LR electronic bombing aids.
The Norden, given clear visibility and trained crews delivered many high value results.
And take note that Fat Man dropped by B-29 neutralized CEP as a high value discriminant.
ObtuseOcelot
Airman
- 21
- Apr 2, 2023
Was there something that made H2X use inherently less accurate than RAF H2S? Or are you comparing RAF blind bombing like Gee/Oboe etc?
Geoffrey Sinclair
Staff Sergeant
- 908
- Sep 30, 2021
RAF pathfinders received specialist training and the RAF tended to use a higher percentage of incendiaries, so a greater chance of fires which are more visible at night. While smoke and dust created by the first bombs quickly degraded visual bombing accuracy markers at night could usually be seen for longer.
The 8th Air Force was in the position of having most of the bombing problems first while needing large amounts of the "solution". It also suffered from "diversions" during the better weather. The 8th's strength in the summer of 1943 was limited by the number of bombers sent to the Mediterranean. It took until August 1943 for 300 strong bomber raids, and this was still the case in October. By late December it was 700 strong raids. In the summer of 1944 there was the need to support Overlord. The war ended before the summer of 1945. In effect the 8th's peak efforts against Germany corresponded to winter and often good weather was reserved for raids on occupied Europe. Weather patterns usually meant more uniform conditions across western Europe compared with the Mediterranean from France to Romania.
The USAAF first tried H2S in September 1943, the first hand-made H2X sets were delivered for operational testing in October 1943, but production sets were only available beginning in February 1944, by the end of the month two 8th Air Force bomber groups had been equipped with H2X, end May it was 6, end July 11, end August 24, then more sets per group. Special USAAF arrangements for D-Day required the resources of the normally non operational training/experimental 482nd Pathfinder Bomb Group. The February 1944 serviceability of the sets was around 77% while for the second half of 1944 it was around 88 to 90%.
The 15th Air Force first used H2X to aim bombs on 15 April 1944, against Bucharest
The problem was compounded by the early failure to realise the need for bombing aids, the initial failures of US experiments with the RAF H2S sets, which set back the program and the fact the 8th Air Force required the aids for every group, and effectively every squadron because of the weather patterns. Then add the acute shortage of people trained to use the sets, tour expired radar men were often retained in Britain for a while rather than being sent back to the US, which was resented at times. The 15th Air Force, with a wide geographic range to cover changed groups over to non visual bombing when they had the equipment and trained men. The pure visual groups would be sent to a target with clear weather forecast, it allowed for better radar training. The 15th was also around half the size of the 8th. The result was the 15th achieved about twice the non visual bombing accuracy of the 8th. The 20th Air Force gained the results of the crash program of trained men and equipment set in place to help the 8th.
America's pursuit of Precision Bombing by McFarland confirms the 8th had the worst radar bombing accuracy, the 15th and 20th Air Forces and Bomber Command were more accurate.
Some flak batteries had the ability to track the H2X radars of USAAF pathfinders and use this for ranging, electronic warfare was a 2 way street, shooting down the H2X aircraft had the expected effects on accuracy.
There is a detailed series of 8th air force bombing results for the period 1 September 1944 to 31 December 1944, 73 days of operations, 60 to 65,000 sorties. Results, in percentage terms, by bombing method, % eff is the percentage of attacks in this period using the relevant method.
A Visual bombing Good to fair visibility, B Visual Bombing poor visibility, C Gee-H, D Micro-H, E H2X 4 to 5/10ths cloud, F H2X 6 to 7/10ths cloud, G H2X 8 to 9/10ths cloud, H H2X 10/10ths cloud, Percentage of bombs dropped within
Note the percentages within 5 miles of the aiming point were very similar for all but H2X under the worst conditions.
USSBS bombing accuracy report, conclusion 9 "H2X was not a precision bombing instrument, it was chiefly valuable as a navigation aid." USSBS bombing accuracy report, accuracy factor number 5, "The amount of cloud obscuration of the target was also a notable factor in bomb accuracy. Indeed before the availability of H2X equipment in the Eighth Air Force in September 1943, it was practically impossible to do any visual bombing if the cloud cover exceeded 5/10. Following the introduction of H2X, the navigation problem was considerably reduced and to some extend bombing improved correspondingly, though it cannot be said that this equipment was in any sense a precision bombing instrument." For example while the first formation using visual bombing scored some 82% the second was 60%, and the 5th and later formations 30%, according to the USSBS
When the USSBS came to evaluate its bombing results they eliminated some errors from the calculations, bombs dropped outside a given distance from the target. Essentially if none of the attacking bomber formations managed at least 5% of their bombs within 1,000 feet of the aiming point the result was termed a mission failure and not counted for accuracy purposes. If a bomber formation failed to drop most of its bombs within 3,000 feet of the target they were not counted for accuracy purposes, a gross error.
Richard Davis Data, January 1942 onwards, short tons N = night, aiming methods
The 8th Air Force was in the position of having most of the bombing problems first while needing large amounts of the "solution". It also suffered from "diversions" during the better weather. The 8th's strength in the summer of 1943 was limited by the number of bombers sent to the Mediterranean. It took until August 1943 for 300 strong bomber raids, and this was still the case in October. By late December it was 700 strong raids. In the summer of 1944 there was the need to support Overlord. The war ended before the summer of 1945. In effect the 8th's peak efforts against Germany corresponded to winter and often good weather was reserved for raids on occupied Europe. Weather patterns usually meant more uniform conditions across western Europe compared with the Mediterranean from France to Romania.
The USAAF first tried H2S in September 1943, the first hand-made H2X sets were delivered for operational testing in October 1943, but production sets were only available beginning in February 1944, by the end of the month two 8th Air Force bomber groups had been equipped with H2X, end May it was 6, end July 11, end August 24, then more sets per group. Special USAAF arrangements for D-Day required the resources of the normally non operational training/experimental 482nd Pathfinder Bomb Group. The February 1944 serviceability of the sets was around 77% while for the second half of 1944 it was around 88 to 90%.
The 15th Air Force first used H2X to aim bombs on 15 April 1944, against Bucharest
The problem was compounded by the early failure to realise the need for bombing aids, the initial failures of US experiments with the RAF H2S sets, which set back the program and the fact the 8th Air Force required the aids for every group, and effectively every squadron because of the weather patterns. Then add the acute shortage of people trained to use the sets, tour expired radar men were often retained in Britain for a while rather than being sent back to the US, which was resented at times. The 15th Air Force, with a wide geographic range to cover changed groups over to non visual bombing when they had the equipment and trained men. The pure visual groups would be sent to a target with clear weather forecast, it allowed for better radar training. The 15th was also around half the size of the 8th. The result was the 15th achieved about twice the non visual bombing accuracy of the 8th. The 20th Air Force gained the results of the crash program of trained men and equipment set in place to help the 8th.
America's pursuit of Precision Bombing by McFarland confirms the 8th had the worst radar bombing accuracy, the 15th and 20th Air Forces and Bomber Command were more accurate.
Some flak batteries had the ability to track the H2X radars of USAAF pathfinders and use this for ranging, electronic warfare was a 2 way street, shooting down the H2X aircraft had the expected effects on accuracy.
There is a detailed series of 8th air force bombing results for the period 1 September 1944 to 31 December 1944, 73 days of operations, 60 to 65,000 sorties. Results, in percentage terms, by bombing method, % eff is the percentage of attacks in this period using the relevant method.
A Visual bombing Good to fair visibility, B Visual Bombing poor visibility, C Gee-H, D Micro-H, E H2X 4 to 5/10ths cloud, F H2X 6 to 7/10ths cloud, G H2X 8 to 9/10ths cloud, H H2X 10/10ths cloud, Percentage of bombs dropped within
| Method | 1000ft | 0.5 mile | 1 mile | 3 miles | 5 miles | %eff |
| A | 30 | 64.3 | 82.4 | 91.5 | 92.2 | 14 |
| B | 9.4 | 34.4 | 53 | 85 | 91.4 | 10 |
| C | 5 | 26 | 56 | 90 | 94 | 15 |
| D | 5 | 25.7 | 52.4 | 78.2 | 88.5 | 3 |
| E | 4.4 | 22.8 | 48.5 | 89.1 | 96 | 3 |
| F | 2 | 12.5 | 36.5 | 84 | 90.5 | 5 |
| G | 1 | 7.3 | 22.5 | 67.4 | 82 | 15 |
| H | 0.2 | 11.2 | 5.6 | 39.8 | 58.5 | 35 |
Note the percentages within 5 miles of the aiming point were very similar for all but H2X under the worst conditions.
USSBS bombing accuracy report, conclusion 9 "H2X was not a precision bombing instrument, it was chiefly valuable as a navigation aid." USSBS bombing accuracy report, accuracy factor number 5, "The amount of cloud obscuration of the target was also a notable factor in bomb accuracy. Indeed before the availability of H2X equipment in the Eighth Air Force in September 1943, it was practically impossible to do any visual bombing if the cloud cover exceeded 5/10. Following the introduction of H2X, the navigation problem was considerably reduced and to some extend bombing improved correspondingly, though it cannot be said that this equipment was in any sense a precision bombing instrument." For example while the first formation using visual bombing scored some 82% the second was 60%, and the 5th and later formations 30%, according to the USSBS
When the USSBS came to evaluate its bombing results they eliminated some errors from the calculations, bombs dropped outside a given distance from the target. Essentially if none of the attacking bomber formations managed at least 5% of their bombs within 1,000 feet of the aiming point the result was termed a mission failure and not counted for accuracy purposes. If a bomber formation failed to drop most of its bombs within 3,000 feet of the target they were not counted for accuracy purposes, a gross error.
Richard Davis Data, January 1942 onwards, short tons N = night, aiming methods
| BC | Tons | 8thAF | Tons |
| experimental | 5.3 | Aphrodite | 40.0 |
| GEE | 5,893.2 | Azon | 70.5 |
| GEE (N) | 13,665.6 | Disney | 51.7 |
| GH | 21,350.6 | GH | 54,781.8 |
| GH (N) | 5,424.0 | GH (N) | 67.5 |
| GH/Vis | 1,354.1 | GH/H2X | 70.8 |
| XX | XX | GH/Vis | 2,069.8 |
| H2S | 27,159.7 | H2S | 1,740.3 |
| H2S (N M/L) | 1,137.8 | H2X | 250,824.7 |
| H2S (N) | 221,287.7 | H2X (N) | 676.1 |
| H2S/Vis | 4,125.7 | H2X/MH | 103.0 |
| Jettison | 6.5 | H2X/Vis | 2,941.5 |
| Loran | 3.5 | MH | 15,953.7 |
| not given | 56,246.5 | not given | 160.3 |
| OBOE | 1,823.5 | OBOE | 418.0 |
| OBOE (N L/L) | 1,279.0 | Oboe (N) | 12.0 |
| OBOE (N) | 266,341.6 | TV | 2.0 |
| XX | XX | TV/GB-4 | 1.0 |
| Vis | 175,089.2 | Vis | 356,434.8 |
| Vis (L/L) | 830.3 | Vis (N) | 61.1 |
| Vis (M/L) | 5,080.4 | Vis/DR | 421.2 |
| Vis (N L/L) | 138.0 | Vis/jettison | 31.5 |
| Vis (N M/L) | 100.4 | ||
| Vis (N) | 186,762.7 | ||
| Vis/(L/L) | 154.0 | ||
| Vis/DR | 5,811.2 | ||
| Vis/DR (N) | 10,439.9 | ||
| Total | 1,011,510.2 | Total | 686,933.3 |
buffnut453
Captain
So statistics were being skewed to make precision daylight bombing appear better than it actually was? That's interesting. Hadn't heard of that before. Just goes to show we need to be certain of "apples to apples" comparisons when examining statistics like these.
ThomasP
Senior Master Sergeant
That may not have been the intent at the time, due to the chance of navigation errors resulting in the bombers not even bombing the right city sometimes.
buffnut453
Captain
I'm afraid navigation errors still impact the ability to strike a target. You can't arbitrarily exclude certain results just because they were too far from the target. Failure to hit the desired target is still a failure. Excluding results just because you don't like them really does sound like an attempt to skew the figures.
33k in the air
Staff Sergeant
- 1,340
- Jan 31, 2021
The RAF experienced that itself plenty of times in its earlier bombing efforts.
ThomasP
Senior Master Sergeant
I do not know if it would make sense to try to count the bombs dropped on a city 25 miles away, many times when they bombed the wrong target they idid not know what the aim point had actually been. I think it would count more as a matter for statistical probability of finding/not finding the target. If you are not even aiming for the right target how can you apply the CEP to the intended target . . . ?
