Best Allied bomber destroyer.

[Shortround6]

That silly weight theory again creeps up...

Yep. Please tell how many 2000hp engines the Germans were using in fighters in 1944? ALL of 1944 not just December?

Indeed they aren't. For bomber killing purposes, I'd rate the Mauser cannon above the Hispano. Faster rate of fire, better HE shells and also weighting about 3/4 of the Hispano. Bombers dont manouver much.

Getting selective in attributes?

Lets try lousier AP ammo.

And while the bombers don't maneuver much the Germans spent a lot of effort trying to get longer ranged weapons. The Hispano had a bit longer range than the MG 151. A bit more on this later.

3 x MG 151/20 on 109 gunboat: 3 x 750 rounds per minute = 2250 rounds per minute. 200 + 2 x 145 rounds = 490 rounds.
2 x MG 131 on 109 gunboat: 2 x 900 rounds per minute = 1800 rounds per minute. 2 x 300 rounds = 600 rounds.
4 x Hispano Mk II. 4 x 600 rounds per minute = 2400 rounds per minute.
4 x 120 rounds = 480 rounds, 4 x 150 = 600 rounds on Typhoon/Tempest IIRC.

Not counting for the better HE shells, which very heavily boosts the Mauser setup, the 3 x 151 vs 4 x Hispano setup comes out at about equal in firepower. The plus side is that the triple Mauser setup weights only about half that of the quad Hispano setup.

Things get funnier when the explosive contents of the M-Geschoss is taken into account. 1 M-Geschoss : 18 gram of explosives, 1 Hisso HE = 10 gram of HE. So the above expressed in HE content/total capacity.

Triple MG 151 setup on 109 gunboat. 2250 x .018 kg per minute = 40 kg of HE / min, total rounds: 490 = 8.82 kg HE
Quad Hisso setup. 2400 x 0.010 = 24 kg of HE / min, 480 rounds carried = 4.8 kg, 600 rounds carried: 6 kg of HE

summary, the triple Mauser gunboat 109 had a potential of delivering about TWICE the HE (40 kg vs 24 kg / min) to a bomber in any given lenght of time, and almost again 1.5x as much in total (4.8-6 kg vs 8.82 kg), at HALF the gun weight.

Key word in this is potential. Since few countries used ALL HE ammo in all belts in all guns on a plane. The Germans used a variety of mixes that ranged from 60% HE mine (3 mine/1 HET/1 AP or APT or APHE) to 40% HE Mine to 33% HE mine( 1 mine/1 HET/1AP or APT or APHE). Germans used 3 different types of shells in their belts. Some of the shells that were NOT HE mine carried as little as 3.6 grams of HE or incendiary material. The APT carried NO explosive or incendiary aside from the tracer. British Hispano belts usually were 50/50 HE and SAPI with the SAPI carrying just under 10 grams of incendiary material. Actual delivered amounts of HE/incendiary could be much close than the "potential". Depending on the "mix" the MG 151 could be delivering an average of 14.4 to 8 grams of HE/incendiary per shell.

Much is made of the wing mounted guns and their convergence "problems". Little seems to be said about the roughly 100meters per second difference in the German shells between the mine shells and the rest of the ammo types and the different ballistic qualities of the shells (shape and sectional density) which do tend to cancel out a bit (high velocity mine shell has poor ballistics and slows down quicker than the other slower to start shells). But it does mean that as the ranges open up the ALL the German shells do NOT arrive at the same point in space at the same time ( or in the original sequence). Or the different ballistics of the 13mm and 20mm guns. Effective range of the MG 151 being about 400 meters with mine ammo vs the cross over range on the wing guns???

At "practical" ranges for most pilots against bombers there really isn't enough difference to get very excited about.

Oh yes and it still runs circles around a P-47.. Soviet trials showed the P-47D10 had turning time of about 27-28 seconds, the gunboat 109 a turn time of 22 seconds.. I am not sure about the Typhoon/Tempest, but they were not quite as good as the Fw 190, which the Soviets measured at about 22-24 seconds IIRC.

And that turning time is at what altitude?? 1000Meters?

I am not saying the P-47 magically turns into a super dog fighter at high altitude but the P-47 is at it's worst at low altitude. AT 8000 meters the P-47 still has full engine power to fight speed bleed off in a turn. At 8000 meters an Early P-47 (toothpick prop) may be able to climb with a "gunboat" 109. While the gun pods don't affect speed that much they do affect climb. I may be reading the charts at the Kurfurst site wrong but it looks like the gun pods could lower the initial rate of climb by as much as 4 meters a second depending on exact model of 109? As you climb higher the difference in rate of climb does not stay the same percentage wise. ( 15% lower rate of climb does NOT mean 15% less at 8000 meters) but is closer to the same loss. ( 4 meters a second loss at sea level is close to a 4 meters a second loss at 8000 meters.)
It is this loss of climbing ability (which is an indication of excess power available) which hurt the gun boats at altitude.

Correct me if I am wrong but that Russian test involves a 360 turn with no loss in altitude?

A 109 with a 605A engine picks up a bit of power over the 1475 rating at sea level/take-off at 1000 meters but at 8000 meters it is down to about 1000hp/PS (give or take a line on the chart) or roughly 2/3 power while the P-47 is still at full power? Which one can do a 360 turn at what speed without loosing altitude.

 

[JtD]

Regarding the explosive content of the projectile - on most parts of a heavy bomber, the 20mm M-round would not cause more damage than a standard round. The M-round worked through gas pressure, and that principle only works in small, confined compartments. A B-17's fuselage and also most parts of the wings are simply to thick and plated with too thick aluminium to leave the round effective. Splinters, as created far more extensively by standard HE shells, will maintain much of their damage potential, even against bigger structures and at some point will be more effective than the M-round. Good spots for the M-round are the wings outside the outboard engines and the tail assembly, but that's about it.

It is one of the reasons why the 30mm round was so much more successful, it packed enough explosives to work against thick bomber wings.

 

[drgondog]

How do you know? Did anyone ever try it?

I'm not saying it can't be done. I'm saying there is a tendency for people to write down things like "stick 4 xyz weapons in fighter abc" without reflecting just what that might involve. History shows that altering the armament of most WW2 fighter aircraft was easier said than done. Most needed considerable testing and development before they worked properly. Some needed considerable modification of the airframe to which they were fitted.
The P-47 was a large and rugged aeroplane but that doesn't mean you can just unbolt 4 machine guns and "stick" 2 cannon in each wing. Who knows what other structures or systems the larger weapons might impinge upon?

Cheers

Steve

The gun Bays in the P-47 wing were 'deeper' than the P-51. The P-51, P-51A, P-51B and A-36 all had the same wing and all equally capable of fitting 4x20mm to match the P-51. Aside from a quick structural examination to look at the airframe structure load absorption there is neither an issue for space to mount the 20mm nor accommodate the ammunition.

If you look at the 4 gun staggered battery for each wing in the P-47, you will note that it has room to mount upright fifties forward and aft in the wing - demonstrating the actual thickness of the wing and favorable placement relative to the spar. When you have depth, you have many options to absorb and distribute load as well as placement to optimize your choices.

Absent any documentation demonstrating the concept - there is no 'knowing'. just educated opinion. I (along with others) put both an XM-188 and 97 20mm Gatling on a Cobra was well as the Wecom 30mm (based on the Mk 108 )
- all of which exerted far greater recoil than the Hispano and Oerlikon 20mm. The inhibiting factor was ROF on the 30mm which was close to airframe natural frequency.

 

[MikeGazdik]

...or how about this thought. Keep making your single engine types to intercept the escort fighters, and build and place a lot more flak guns. What caused more 8th AF bomber losses, flak or fighters?? I'm guessing flak but not sure.

 

[JtD]

Flak vs. fighters is a question of efficiency, and generally fighters are more efficient.

 

[Juha]

Hello Tante Ju.
A couple notes
the rate of fire of Hisso Mk V was 750rpm (the armament of Tempest Mk V, 200rpg), Mk II had the 600rpm you mentioned. And did the LW Bf 109Gs carry the 200 rounds for their fuselage MG 151/20? At least to Finns they told that the 230 rounds (200 in the ammo box and 30 on the ammo tray from the box to the breech) belt was too heavy and tended to broke in the middle so they recommended to Finns who complained on the breaking belts to load with 125 rounds in the box and 30 in the tray, so 155 rounds altogether. And the Hisso had better penetrating power and a hole(s) in the pilot, spar or engine is often fatal to a bomber as was easily 20mm SAPI through a fuel cell even if HE was generally more effective than AP/SAPI.

And 4 Hisso Mk IIs was clearly very effective armament against Ju 88/188 or Do 217 as shown when Typhoons met Do 217s of KG 2 or Mossies Ju 88s/188s of KG 26. Even LW crews knew that and behaved accordingly.

Juha

 

[stona]

Flak caused the majority of battle casualties amongst aircrew late in the war. Flak concentrations increased considerably in 1944/5.
The 8th Air Force carried out a survey of battle casualties in June, July and August 1944.

"Table 183 gives the causes of the wounds sustained by the 1,117 casualties. Approximately 86 percent of the casualties were hit by flak fragments. Less than 4 percent were hit by shells or shell fragments fired from enemy fighter planes. Practically all of the 7.8 percent of casualties hit by secondary missiles were the result of flak hits on the aircraft. Secondary missiles include fragments of Plexiglas; pieces of dural from the skin of, or objects in, the plane; bulletproof glass; brass fittings; and parts of electrical heating and radio equipment and .50 caliber machinegun ammunition."

Flak was certainly doing most damage to the men in the aircraft.

"Of the WIA battle casualties, 23 (2.3 percent) sustained traumatic amputations; 20 of these amputations were due to flak. Of the remaining three, two were due to 20 mm. shells. The missile responsible for the amputation in the third case was not discovered. Two casualties had two amputations, one of both thighs and the other of one thigh and one arm. In the KIA group, all but one arm amputation, for which a 20 mm. cannon shell was responsible, were due to flak."

Of the small number of men killed or wounded by fire from enemy fighters most were hit by 20mm cannon fire, rather than the much rarer larger calibre rounds, which is not surprising.

"In the present survey, 50 battle casualties (4.5 percent) were known to be due to missiles fired from enemy aircraft. Their distribution according to missile (figs. 284, 285, and 286) and type of casualty is shown in table 218. Cannon shells (20 mm.) accounted for 88 percent of the casualties."

Waist gunner, tail gunner and radio operator were most likely to be hit by rounds fired from a fighter, in that order. Waist gunner, tail gunner and bombardier were most likely to be killed by all causes, again in that order.

Cheers

Steve

 

[tomo pauk]

The destruction of the LW from spring of 1944 on contributing to a skewed damage ratio, Flak vs. fighters?

 

[stona]

Westermann says that about half of all US aircraft combat losses were due to Flak.

The RAF's own official history gives a figure for Bomber Command of 37% lost to Flak between July '42 and April '45, 1229 of 3302. That is obviously mainly at night.

I haven't read Westermann for a while, but I'll have a flick through if I get a chance.

An RAF ORS report of January 1942 seems to reach a similar conclusion to Westermann for daylight operations.

"While it is impossible to deduce the proportion of aircraft destroyed by flak, it can be said that it is greater than 20% of the total aircraft missing both by day and night. Such information as available suggests that during the day sorties fighters and flak have been equally lethal."

Just to muddy the waters a bit another, slightly later, ORS report stated.

"damage by fighter is more often lethal than damage by flak."

On 6th March 1944 672 of the 730 8th AF bombers that took off attacked Berlin. 318 returned to the UK with at least some Flak damage. That's 48%.

During the war in Europe the USAAF lost 5,400 aircraft to Flak and 4,300 shot down by enemy aircraft.

31% of 8th AF bomber losses to all causes, not just combat related, were attributed to flak.

You could easily argue that flak was overall a better way to shoot aircraft down than fighters. It's an argument that raged in Germany for years.

Cheers

Steve

 

[JtD]

Flak is good at damaging aircraft, but bad at killing them. Heavy AAA doesn't really engage single targets, they fire up a barrage. If the odds are that 50% of the attacking aircraft come through undamaged, 45% get damaged and 5% get killed, this doesn't change if you have a single bomber instead of a formation. It still has a 50% chance to make it home undamaged. If you send up a fighter wing to engage a formation, and you'll get 80% home undamaged, 10% damaged and 10% get killed, these odds get dramatically worse if you use less aircraft and a single bomber would almost certainly get wiped out.

FWIW - in April 1944, when the Luftwaffe was putting up their hardest fight (big week), the 8th AF lost 314 heavy bombers to fighters, and 105 to AAA. First month the 8th AF lost more heavy bombers to AAA than to fighters was June 44. In the ETO, by the end of the war, the 8th AF attributed 2452 losses to enemy fighters and 2439 to AAA.

 

[stona]

Flak is good at damaging aircraft, but bad at killing them. .............. In the ETO, by the end of the war, the 8th AF attributed 2452 losses to enemy fighters and 2439 to AAA.

If flak "killed" as near as dammit 50% of the 8th AF's bombers your two sentences appear to be mutually exclusive.

Damaging bombers is a good way of using up your enemies resources. I bet a significant proportion of the spare parts had to be shipped across the Atlantic. Killing and injuring the crews, at which flak was significantly more effective than fighters, is another very good way of degrading your enemies efficiency, morale, and means to fight.

As I posted above, for all aircraft and all types of flak, for the USAAF, 56% were lost to flak (5,400 of 9,700).

I think it is because the relative success of flak and fighters is so close that the debate raged......and still does

Cheers
Steve

 

[tomo pauk]

...
As I posted above, for all aircraft and all types of flak, for the USAAF, 56% were lost to flak (5,400 of 9,700).

...

Steve, how many were lost to the light Flak (37mm and under)? Any info about how many planes were lost in the last war year (May 1944 - May 1945)?

 

[JtD]

If flak "killed" as near as dammit 50% of the 8th AF's bombers your two sentences appear to be mutually exclusive.

Appearances can be deceiving.

 

[stona]

Steve, how many were lost to the light Flak (37mm and under)? Any info about how many planes were lost in the last war year (May 1944 - May 1945)?

Late in the war I expect a lot of aircraft, not heavy bombers, were lost to light flak. The data must be available, though the 8th AF didn't specify how it's losses were incurred before some time in 1943 if I remember correctly.
I'll see what I can find, the light flak data may be available in the 8ths own history, compiled shortly before the end of the European war but it will take some digging.
Cheers
Steve

 

[drgondog]

Flak is good at damaging aircraft, but bad at killing them. Heavy AAA doesn't really engage single targets, they fire up a barrage.

Three types of Flak. Barrage or Predicted in which the airspeed range and heading are cranked in and multiple heavy batteries fire into a region of space ahead and into the bomber stream. Aimed Flak in which one or more heavy Flak guns pick a specific bomber to shoot at and do so. Then there is light Flak (20mm and 37mm) which is Aimed at specific aircraft (fighters dominantly). The 8th AF lost approximately 878 fighters to light flak.

If the odds are that 50% of the attacking aircraft come through undamaged, 45% get damaged and 5% get killed, this doesn't change if you have a single bomber instead of a formation. It still has a 50% chance to make it home undamaged. If you send up a fighter wing to engage a formation, and you'll get 80% home undamaged, 10% damaged and 10% get killed, these odds get dramatically worse if you use less aircraft and a single bomber would almost certainly get wiped out.

Not an accurate analogy

FWIW - in April 1944, when the Luftwaffe was putting up their hardest fight (big week),

Big Week was February 20th through 25th, 1944

the 8th AF lost 314 heavy bombers to fighters, and 105 to AAA. First month the 8th AF lost more heavy bombers to AAA than to fighters was June 44. In the ETO, by the end of the war, the 8th AF attributed 2452 losses to enemy fighters and 2439 to AAA.

What source are you using? I.e. 8th AF FC lost approximately 640 in air combat and ~ 878 to flak and 2311 'did not return' to all causes including air/flak/operations and accidents.. That number does not include Class E salvage/hanger queens due to battle damage.

 

[stona]

Appearances can be deceiving.

I'm not sure I understand. If both flak and fighters accounted for about 50% of bombers destroyed then they were both efficient bomber killers. The economic argument is something different and again has been going on for years.
Best estimates are that it cost 267,440 RM to shoot down an aircraft with heavy flak. This converts into well less than half the price of a B-17. It cost a mere 37,050 RM to shoot down an aircraft using light flak.
The cost of shooting down an aircraft with a fighter is impossible to estimate due to the enormous costs of designing, producing, maintaining an aircraft as well as all its support infrastructure, air fields etc. It is unlikely to be a cheaper option. Fighters and their expensively trained crews were much more likely to be destroyed in the battle than anti aircraft artillery and its crews too.

In August 1944 Hitler seems to have preferred flak. We have two accounts of a somewhat heated meeting and what Hitler said, the first from Speer.

"I want no more planes produced at all. The fighter arm is to be dissolved. Stop aircraft production! Stop it at once, understand? You're always complaining about the shortage of skilled workers, aren't you? Put them in flak production at once. Let all the workers produce anti-aircraft guns. Use all the material for that too! Now that's an order. ... A program for flak production must be set up. ... A program five times what we have now. . . . We'll shift hundreds of thousands of workers into flak production. Every day I read in the foreign press reports how dangerous flak is. They still have some respect for that, but not for our fighters."

The second from Galland.

"I will disband the fighter arm. With the exception of several advanced fighter Groups, I will carry on air defence solely with anti-aircraft defences. Speer, I order you to immediately submit a new program. Production is to be switched from fighters to flak guns and increased immensely."

Cheers

Steve

 

[stona]

I found some statistics to show how effective flak could be.

Between April 5th and May 19th 1944 the 15th AF lost 233 bombers in attacks on Ploesti. Of these 131 were accounted victims of flak and 56 of fighters. The 15th did not face the same numbers or concentrations of fighters as the 8th which will skew the figures to the ratio of 2.3:1 in favour of the flak. In addition a further 556 bombers were rated as "seriously damaged".

Later that year we have this table. It is important to note that on average between 15% and 25% of aircraft damaged were considered "seriously damaged". That may be as many as 2,000 aircraft for the 8th AF.

The human consequences of seriously damaged aircraft in terms of numbers wounded I haven't found, but they will not be negligible.

Cheers

Steve

 

[JtD]

I'm not sure I understand. If both flak and fighters accounted for about 50% of bombers destroyed then they were both efficient bomber killers.

Hardly. I also suppose you're talking about effectiveness, not efficiency. Effectiveness, i.e. net result, is that up to April 1944 the 8th AF lost a heavy bomber for each 23 effective sorties, whereas they lost one in 69 thereafter. That certainly wasn't because the Germans reduced their AAA.

You will see the same picture if you look into naval aviation, there were reasons why escort carriers were considered extremely valuable.

But the point I was making about "killing", is that after the Luftwaffe's doctrine went from maximum damage to maximum number of kills, most of the bombers damaged by fighters were in the end shot down, whereas most of the bombers damaged by AAA returned to base. There are stats for that around, I read them once, but can't point you to them right now. Edit: Fortunately you posted some, there's one 8th AF bomber killed for 32 damaged. That's basically what I was saying. AAA is good at damaging them, but bad at killing. Same stats for fighters were like 4 killed for each 1 damaged (sorry if that turns out to be inaccurate).

Regarding you excursion economics, remember that all the infrastructure would need to be there for any aircraft, and in fact bombers have far higher requirements than fighters. Fighters could and did operate out of little more than level meadows with a fuel truck and a couple of tents on the side. Also, intercepting bombers is not the only thing fighters do. And did you count the Autobahn and railways into the cost for the AAA? As opposed to aircraft, heavy guns don't just fly to where they are needed. Bottom line here: I don't accept your figures, because I don't think it's feasible to come up with a number at all.

Little add on: It's not the idea of a defensive system to be cost effective, i.e. to cost the enemy more then it's costing you. That's the concept of an attack weapon. The idea of the defensive system is to prevent damage, effectively. Any bomber that got through is an expression of the failure of the air defence system, and AAA doesn't have a good record in that regard.

 

[stona]

The flak and the fighters were part of an integrated air defence system. The whole system failed in the end for Germany, not any one part of it.

Flak certainly damaged a lot of bombers, far more than the fighters. I don't have any figures for the cost in men and resources to repair the 15-20% of bombers estimated to be seriously damaged, but I bet it was significant. Every ton of materiel crossing the Atlantic came at the cost of something else as well as ships and seamen.

Many of the bombers shot down by fighters had previously been damaged by flak. One Luftwaffe pilot went on the record stating "That was the old fighter pilot's trick. The successful ones built up their scores in this way."

Which ever way you want to spin it the 8th AF's own statistics are clear about the human cost. 85% of casualties were caused by flak.

There's no point in labouring the economic argument. It has been tried for years and there are too many unknowns. I would suggest that neither arm has a clear advantage. You might not think that it is important for a defensive system to be cost effective, but if you are a government, with your back to the wall, marshalling limited and ever diminishing resources it is an important factor.

Fixing the Me 210 cost Messerschmitt 37,000,000RM, you can shoot down a lot of bombers and build a lot of flak guns for that. That's what I mean by the high costs involved in developing aircraft. It is by no means an isolated instance. Aircraft might well operate from an airfield, but I guarantee that the cost of producing and transporting the Jagdwaffe's fuel and armaments and other operational costs would not be over shadowed by the cost of producing the 1.4 million rounds of flak ammunition which was the highest monthly production of the war.

Cheers

Steve

 

[JtD]

You might not think that it is important for a defensive system to be cost effective, but if you are a government, with your back to the wall, marshalling limited and ever diminishing resources it is an important factor.

I think you've missed my point again. What you're talking about would be efficiency, I was referring to effectiveness. I actually spelled out what I meant: "to cost the enemy more then it's costing you". A defence system is still a failure even if it kills something for no cost at all, but ultimately fails to defend whatever it is tasked to to defend.

Since we're way off topic that's all from me.