The Flak Gap

[treespider]

I posted this in another thread...doesn't sound like skip bombing was a free ride...
 
Note:
1. How many times this guy brings back a shot up B-17?
2. When the missions first started?
3. At what time of day were they conducted?
 
from:

http://www.afa.org/magazine/valor/1290valor.asp

Skip-Bombing Pioneer


In the fall of 1942, a better way of sinking Japanese ships had to be found. Ken McCullar was one of the first to master the new tactic.

A priority task for the few Fifth Air Force B-17s of the 19th and 43d Bombardment Groups during the summer of 1942 was interdicting the Japanese sea line of communications from Rabaul, New Britain, to enemy forces on New Guinea. AAF doctrine then held to bombing from altitude with nine-plane (when that many were available) squadron formations. Results had not been good, especially against maneuvering ships. Only about 1 percent of bombs dropped were hitting their targets. Clearly a better way had to be found.

Promising experiments with skip bombing were under way in the US, based on RAF experience. Lt. Gen. George Kenney, commander of Fifth Air Force, was enthusiastic about the new technique. The 63d Squadron of his 43d Bombardment Group set to work in September, testing skip bombing with B-17s against a wrecked ship in Port Moresby Harbor. Approaching the target at 200 mph, aircraft released bombs at 200 feet or lower, about 300 yards from the hulk. The bombs would skip across the water into the side of the ship--if airspeed, altitude, and range were properly coordinated. Modified Australian fuzes were used in the absence of suitable US stock.

Capt. Kenneth McCullar already was credited with sinking or damaging four Japanese vessels, using conventional tactics. He soon became one of the most proficient practitioners of skip bombing, with 60 percent hits in practice runs. Skip bombing looked like the answer, but it added another element of danger to the normal hazards of combat. Chief among these was the nerve-racking experience of flying at point-blank range directly into the muzzles of deck guns on enemy ships. Since the older B-17s didn't have enough forward firepower to keep those guns down, early skip-bombing attacks were made at night, by the light of the moon or flares.

The Japanese were introduced to skip bombing at Rabaul Harbor on the night of Oct. 23, 1942. While six B-17s of the 64th Squadron bombed from 10,000 feet, six 63d Squadron bombers came in at 100 feet to skip their bombs into the sides of Japanese ships. McCullar reported sinking a destroyer with two hits amidships. Two nights later the 63d returned to Rabaul with eight B-17s, about a third of the Fifth Air Force's operational heavy bombers at the time. McCullar was one of four to score hits.

McCullar flew many more skipbombing missions; one of the most notable was on the night of Nov. 24, when he and other B-17 crews attacked an enemy convoy by flare light. His first run at 200 feet scored a near miss on a destroyer. On his second run, McCullar set the destroyer afire.

Coming back once more, his No. 1 engine was knocked out by flak, and the propeller couldn't be feathered. Too badly shot up for another low attempt, McCullar made a conventional bomb run at 1,200 feet and again was hit. He then climbed to 4,000 feet for a fifth attack and lost No. 3 engine to enemy fire. With only two engines running and three wounded men aboard, he was faced with a return to Port Moresby over 13,000-foot peaks. No. 3 finally was brought in at greatly reduced power. "Two and a half hours later," McCullar reported, "we were at 10,000 feet, our ceiling, and luckily we found a pass to sneak through, landed OK, and forgot about it."

Twice more McCullar brought his B-17 home on two engines, once from nearly 600 miles from Rabaul where he was on a photo-reconnaissance mission. Seventy miles short of Rabaul, a supercharger blew up, killing both engines on the left wing. McCullar completed the mission on two engines and flew back to Port Moresby with excellent photos of the Rabaul area. Two days later, on Dec. 7, he helped turn back a Japanese convoy, returning with more than 100 machine-gun and 20-mm holes in his B-17.

McCullar, by this time a major, led a charmed life, it would seem. His skill as a pilot and his determination to complete every mission regardless of the odds had earned him a Distinguished Service Cross. Then, as with so many other combat heroes, the odds caught up with him. On April 12, 1943, while taking off for an attack on a convoy, his B-17 crashed in flames.

"His exploits were already legends that would be told and retold long after the war," Kenney said. McCullar was a symbol of valor i n the dark days of the Pacific war. His courage and resolution should remain an inspiration to those who follow almost a half-century later.

[Big B]

ORIGINAL: Apollo11

Hi all,

The Japan's inability to target (i.e. lack of German like radar technology) at night is understandable but having huge bombers flying slow and low in broad daylight is something completely different and that's why I am constantly reminding community of very important so-called "FLAK Gap" problem...


Leo "Apollo11"

Ok, I read your thread links, but seeing how there is no minimum altitude setting in the DB - ...what's the solution (if any)?
Limit all Hvy AAA to 25,000 feet?
Edit: And if this is accurate, should it be eliminated?

ORIGINAL: MineSweeper

Treespider, here is a chart showing the capabilties (range wise) of AA guns (German)....FYI....need to find the japanese models......

[jwilkerson]

ORIGINAL: Big B

ORIGINAL: Apollo11

Hi all,

The Japan's inability to target (i.e. lack of German like radar technology) at night is understandable but having huge bombers flying slow and low in broad daylight is something completely different and that's why I am constantly reminding community of very important so-called "FLAK Gap" problem...


Leo "Apollo11"

Ok, I read your thread links, but seeing how there is no minimum altitude setting in the DB - ...what's the solution (if any)?
Limit all Hvy AAA to 25,000 feet?

Defining the solution - but would depend on first defining the problem!

[Big B]

ORIGINAL: jwilkerson

ORIGINAL: Big B

ORIGINAL: Apollo11

Hi all,

The Japan's inability to target (i.e. lack of German like radar technology) at night is understandable but having huge bombers flying slow and low in broad daylight is something completely different and that's why I am constantly reminding community of very important so-called "FLAK Gap" problem...


Leo "Apollo11"

Ok, I read your thread links, but seeing how there is no minimum altitude setting in the DB - ...what's the solution (if any)?
Limit all Hvy AAA to 25,000 feet?

Defining the solution - but would depend on first defining the problem!

You beat me to it - see above your post

[castor troy]

ORIGINAL: rtrapasso

ORIGINAL: castor troy

while I know of raids with heavy bombers against the home islands I doubt that in real war the Japanese AA defense was so bad that in real life Allied commanders could have come up with the same they do in WITP: THE LOWER THE BETTER! I see that in all my games (excluding Nikmod - which IMO seems a bit too effective [;)]).

What I´ve experienced in years of playing: 6000 feet must be the just perfect altitude for Allied bombers. No morale hit, best accuracy, weak flak (too high for effective small AA gun fire, too low for heavy AA guns). When flak is more dangerous at 20.000 feet why come in high if I can go in at 6000 feet also. 6000 ft still too much flak, let´s go lower... 2000 ft seems perfect now... let´s go on at 2000 ft...

No doubt that Japanese flak was not what you would like it to be as a Japanese commander. Though I doubt that in 4 years of war there would not be a real quick development of AA defense if the standard, perfect, super dupi altitude of Allied 4Es would be 6.000 ft.

Again: in WITP what "normally" happened in real life - means a lot of flak, let´s go higher - is reverted in the game - means a lot of flak, let´s go lower... [8|]

Actually, IRL - it did work out to "lots of flak - let's go lower" - and evolved into skip bombing, where flak losses were cut to a minimum, and casualties went down, bombing accuracy went up, and morale went up. Of course, this is not exactly what happens in the game where the morale drops, and you get cut up with 100' attacks. And remember: the tactics were first worked out (for the US) by B-17s (4E heavy bombers), although the speedier mediums perfected the method later.

If one demands accuracy in the game model - would you be willing to swap fixing "the flak gap" for realistic skip-bombing attacks?

I wonder why in real life, when I read at what altitude all those bombers bombed, they didn´t ALL go down to 2000 feet if this would be completely safe then.

And it has nothing to do with swapping the flak gap for skip bombing. Both things are IMO not what they should be. The next one will say, would you swap the 100% cap shield for a Kamikaze threat like it was in real life. Or whatever.

To repeat myself: if flak would have been in real life what it looks like in WITP then in real life all attacks would have been between 2000 and 5000 feet. And I doubt there would have been no attempt to make it a little bit more dangerous in real life in 4 years. Can´t be very hard to hit a more or less slow moving 4E bomber formation at 3000 feet with fast firing "small" AA guns.

[jwilkerson]

You beat me to it - see above your post

Hum, still not sure I see the problem statement?

[Big B]

ORIGINAL: castor troy

ORIGINAL: rtrapasso

ORIGINAL: castor troy

while I know of raids with heavy bombers against the home islands I doubt that in real war the Japanese AA defense was so bad that in real life Allied commanders could have come up with the same they do in WITP: THE LOWER THE BETTER! I see that in all my games (excluding Nikmod - which IMO seems a bit too effective [;)]).

What I´ve experienced in years of playing: 6000 feet must be the just perfect altitude for Allied bombers. No morale hit, best accuracy, weak flak (too high for effective small AA gun fire, too low for heavy AA guns). When flak is more dangerous at 20.000 feet why come in high if I can go in at 6000 feet also. 6000 ft still too much flak, let´s go lower... 2000 ft seems perfect now... let´s go on at 2000 ft...

No doubt that Japanese flak was not what you would like it to be as a Japanese commander. Though I doubt that in 4 years of war there would not be a real quick development of AA defense if the standard, perfect, super dupi altitude of Allied 4Es would be 6.000 ft.

Again: in WITP what "normally" happened in real life - means a lot of flak, let´s go higher - is reverted in the game - means a lot of flak, let´s go lower... [8|]

Actually, IRL - it did work out to "lots of flak - let's go lower" - and evolved into skip bombing, where flak losses were cut to a minimum, and casualties went down, bombing accuracy went up, and morale went up. Of course, this is not exactly what happens in the game where the morale drops, and you get cut up with 100' attacks. And remember: the tactics were first worked out (for the US) by B-17s (4E heavy bombers), although the speedier mediums perfected the method later.

If one demands accuracy in the game model - would you be willing to swap fixing "the flak gap" for realistic skip-bombing attacks?

I wonder why in real life, when I read at what altitude all those bombers bombed, they didn´t ALL go down to 2000 feet if this would be completely safe then.

And it has nothing to do with swapping the flak gap for skip bombing. Both things are IMO not what they should be. The next one will say, would you swap the 100% cap shield for a Kamikaze threat like it was in real life. Or whatever.

To repeat myself: if flak would have been in real life what it looks like in WITP then in real life all attacks would have been between 2000 and 5000 feet. And I doubt there would have been no attempt to make it a little bit more dangerous in real life in 4 years. Can´t be very hard to hit a more or less slow moving 4E bomber formation at 3000 feet with fast firing "small" AA guns.

I really don't know the answer, was it because the Nordin Bombsight worked bettrt at high altitude?

[castor troy]

ORIGINAL: treespider
Skip-Bombing Pioneer


In the fall of 1942, a better way of sinking Japanese ships had to be found. Ken McCullar was one of the first to master the new tactic.

A priority task for the few Fifth Air Force B-17s of the 19th and 43d Bombardment Groups during the summer of 1942 was interdicting the Japanese sea line of communications from Rabaul, New Britain, to enemy forces on New Guinea. AAF doctrine then held to bombing from altitude with nine-plane (when that many were available) squadron formations. Results had not been good, especially against maneuvering ships. Only about 1 percent of bombs dropped were hitting their targets. Clearly a better way had to be found.

hoooohoooo, looks like skip bombing is already perfectly modeled in the game (only the alt is wrong), because all level bombers - of course especially 4Es - are NOT achieving hit rates of 1% but far, far more. When bombers already nearly achieve hit rates at 6000-10000 ft level bombing like they would in real life doing skip bombing....


but once again, this has nothing to do with the fact that Allied bombers can bomb below 6000 ft for free for 4 years...

[Big B]

ORIGINAL: jwilkerson

You beat me to it - see above your post

Hum, still not sure I see the problem statement?

I meant...is there really a problem? given the evidence of German Flak altitude effectiveness..

[jwilkerson]

ORIGINAL: Big B

ORIGINAL: jwilkerson

You beat me to it - see above your post

Hum, still not sure I see the problem statement?

I meant...is there really a problem? given the evidence of German Flak altitude effectiveness..

As I covered in the posts in the previous threads - I think the only "problem" (and I'm talking about the bombing of land targets - not ships) is the "predictability" of the "gap" as represented in the game. The 6000 foot altitude should ideally be fuzzied up a bit so that it isn't the "known safe" haven that it is. But the historical evidence indicates that HAA had difficulty tracking targets at low altitude - and hence that representing some kind of "flak gap" makes sense.

As to bombing of ships versus bombing of land targets, I think we need to focus on one of these at a time. IRL the aircraft attack profiles were different, the layout of the flak defense was different and the routines that handle these two aspects in the game are totally different. When we've talked about the "flak gap" in the previous threads, we were talking about land targets and I think that is where the dicussion is most meaningful.

[treespider]

ORIGINAL: jwilkerson

ORIGINAL: Big B

ORIGINAL: Apollo11

Hi all,

The Japan's inability to target (i.e. lack of German like radar technology) at night is understandable but having huge bombers flying slow and low in broad daylight is something completely different and that's why I am constantly reminding community of very important so-called "FLAK Gap" problem...


Leo "Apollo11"

Ok, I read your thread links, but seeing how there is no minimum altitude setting in the DB - ...what's the solution (if any)?
Limit all Hvy AAA to 25,000 feet?

Defining the solution - but would depend on first defining the problem!

The "Problem" is that guns set with high ceilings are not firing at aircraft below a particular ceiling whereas they could have fired IRL utilizing direct/ barrage / area fire...I'm not suggesting the fire would have been accurate or effective just that their would have been some fire as opposed to none...note the German 'effectiveness chart is a solid line from the ground to 37,000 feet ..

[Mike Scholl]

ORIGINAL: treespider

ORIGINAL: Mike Scholl

"Effective" is the key word. The shell might be effective at 2.5 miles..., but delivering it accurately against a rapidly moving target with a hand-directed mounting at that range is wishfull thinking at best.

Then why don't you find us some real data on the 13mm before coming out with your bombastic statement that the research for the game sucks....

The graphic earlier presented similar style info...effective vs. maximum ceiling...

"Spider" I direct your attention to the "effective ceiling" shown for the German 20mmL65 (a better weapon by far than the Japanese 13mm HMG). It shows the shells will reach to almost 15,000 feet, and I venture to guess they would explode and do damage at 13,000 if they hit something. But the "effective" ceiling is shown at less than 5,000, because the chance of actually hitting something went to almost "nil" at that point. The table shown in the forum for the German AAA uses a more stringent and accurate definition of the term "effective"..., which is the point I was making. The chart you posted gives the "theoretical effective range" of the shell, while the one on German AA weapons shows the "realistic effective range" of the weapons system. And I maintain that the chart based on real life performance is a much more accurate evaluation of "effective".

[Big B]

ORIGINAL: Big B

According to this chart, there is a clean operating altitude of 20,000 to 25,000 feet where all flak is ineffective - that would certainly explain why bombing over Europe was conducted above 20,000 feet.

[castor troy]

I found this one:

We in B-24s typically bombed from about 22,000 feet while the B-17s, which could fly higher, bombed from around 27,000, particularly at tough targets where higher was better in an effort to avoid the flak as much as possible.

Sincerely,
Ronald D. Spencer
788th Bomb Squadron
467th Bomb Group
96th Bomb Wing
2nd Bomb Division
8th Air Force


European theater. So if this chart about flak ceilings is true then a B24 seemed never to be in trouble of being hit from a German 150mm, 105mm or 88mm flak gun because they then flew only in the "effective" range of 50mm guns. Hmmmmmmm


While this is from the European theater I still think that the "normal" tactic (also in the Pacific) was to fligh HIGHER, not lower, to avoid flak! Not so in the game where 2000-5000 feet seems far safer than 15000 - 20000 (of course only if there´s also flak, if there´s just a BF with small AA guns left that can´t shoot to 15000 ft it might be different).



Edit: ahh, sorry I seem to read the chart wrong. I saw the "accurate engament" arrows and thought from there upwards the flak gun would be effective.

But this makes this chart even more whopping for me! This chart seems to say that at least German guns were EFFECTIV nearly from the ground upwards... If that´s correct and Japanese "real AA guns" started being effective from 5000 - 7000 then it´s no wonder for me they lost the war...[8|]

[treespider]

ORIGINAL: Mike Scholl

ORIGINAL: treespider

ORIGINAL: Mike Scholl

"Effective" is the key word. The shell might be effective at 2.5 miles..., but delivering it accurately against a rapidly moving target with a hand-directed mounting at that range is wishfull thinking at best.

Then why don't you find us some real data on the 13mm before coming out with your bombastic statement that the research for the game sucks....

The graphic earlier presented similar style info...effective vs. maximum ceiling...

"Spider" I direct your attention to the "effective ceiling" shown for the German 20mmL65 (a better weapon by far than the Japanese 13mm HMG). It shows the shells will reach to almost 15,000 feet, and I venture to guess they would explode and do damage at 13,000 if they hit something. But the "effective" ceiling is shown at less than 5,000, because the chance of actually hitting something went to almost "nil" at that point. The table shown in the forum for the German AAA uses a more stringent and accurate definition of the term "effective"..., which is the point I was making. The chart you posted gives the "theoretical effective range" of the shell, while the one on German AA weapons shows the "realistic effective range" of the weapons system. And I maintain that the chart based on real life performance is a much more accurate evaluation of "effective".

I'll "see" your statement and raise you with the data for the german 20mm from the same source I quoted before...

Range
.
Elevation With 0.300 lbs. (0.134 kg) HE Shell
Range @ 45 degrees 5,360 yards (4,900 m)
AA Ceiling @ 85 degrees 12,140 feet (3,700 m)

According to Navweapons the german 20mm max altitude does not even equal the 13mmm effective altitude...

[Big B]

Maybe I misread the chart - what is the minimum altitudes for Hvy AAA?

[treespider]

ORIGINAL: Big B

ORIGINAL: Big B

According to this chart, there is a clean operating altitude of 20,000 to 25,000 feet where all flak is ineffective - that would certainly explain why bombing over Europe was conducted above 20,000 feet.

I read the chart that accurate engagement is possible within the band of the solid line ( not at the point where it terminates but everything upto that point)... then after the solid line is the dashed line where accuracy falls off...note that in the description it sayd accurate engagement ranges are far short of where the round self destructs...

[castor troy]

If we just could find such a chart about Japanese AA guns...

[Big B]

ORIGINAL: Big B

Maybe I misread the chart - what is the minimum altitudes for Hvy AAA?

Bump

ORIGINAL: castor troy

If we just could find such a chart about Japanese AA guns...

I would think - guns are guns - it's probably quite similar

[Nikademus]

According to Westerland's study on German flak defences 1939 - 45, there was no exploitable or predicitble "flak gap"