Best armed fighter

[HoHun]

Hi Hardwarefreak,

>1. Excellent stable gun platform, no engine torque or rudder trim issues

Hm, the British Purchasing Commission noted that the P-38 required constant directional re-trimming after each power change because the two engines would never arrive at exactly the same power setting.

>2. Tightly grouped/focused battery of 5 guns

We agree on that. Have you seen the animated GIF above?

>No matter where the stream hit, serious structural damage was a result. Engine, wingroot, outer wing panel, cockpit, rear fuselage, tail--it didn't really matter.

Do you have a source on that?

`>This also would have yielded a cyclic battery rate of about 106 rounds/sec (assuming 800 rds/sec per gun) firing in a spread of about 2 ft x 3 ft.

Since you are new to this thread, please check out the paragraph on the "shotgun misunderstanding" above.

Regards,

Henning (HoHun)

 

[Kurfürst]

HoHun,

Would it be too much to ask for a similiar animated GIF for the Bf 109G, with MG 151/20 or MK 108 central gun, and gunpods?

 

[HoHun]

Hi Kurfürst,

>Would it be too much to ask for a similiar animated GIF for the Bf 109G, with MG 151/20 or MK 108 central gun, and gunpods?

Right now, I have collected the trajectory data and assembled the pieces, now it just remains to collect the screenshots and make the GIF

(Exactly for the configuration you suggest, coincidentally!)

Regards,

Henning (HoHun)

 

[HoHun]

Hi again,

>Would it be too much to ask for a similiar animated GIF for the Bf 109G, with MG 151/20 or MK 108 central gun, and gunpods?

Here it is!

Regards,

Henning (HoHun)

 

[Kurfürst]

Superb! BTW, you might find it interesting to check my site, I have just uploaded a rather theoretical study about turning calculations!

 

[HardwareFreak]

Hi Hardwarefreak,

>1. Excellent stable gun platform, no engine torque or rudder trim issues

Hm, the British Purchasing Commission noted that the P-38 required constant directional re-trimming after each power change because the two engines would never arrive at exactly the same power setting.

Hello HoHUn,

The British Purchasing Commission received 'castrated Lightnings', with Allisons that rotated in the same direction, and without the GE turbochargers. This was their own doing as they didn't want the counter rotating engines that were required to make the P-38 work properly. They wanted the same engine in both nacelles to ease maintenance. This caused lateral torque problems, and is more to blame for their re-trimming issues than uneven throttle settings. If they'd have purchased the Lightning as it was designed, they'd not have had this issue. Or, at least, not to the extent that they did.

>2. Tightly grouped/focused battery of 5 guns

We agree on that. Have you seen the animated GIF above?

Absolutely. This is the main reason I vote for the P-38 as the answer to the question of this thread. If, for some odd reason, Lockheed had given it wing guns instead, I wouldn't even consider the P-38. And yes, those GIFs are kinda neat. I'm not sure how accurate they are, but they give an excellent graphical understanding of static trajectory. Unfortunately, most aircraft that were being fired upon were likely making evasive maneuvers.

Focused fire that does the maximum amount of damage in the smallest area is what kills vehicles the best, whether it's aircraft, tanks, trucks, etc. By disrupting the structural integrity of the vehicle, said vehicle will then, in essence, due to gravity or locomotion, destroy itself. If you destroy the integrity of a wing spar by punching enough holes in it, the wing is going to fold and come off the airplane, same with the tail spar(s). If you punch a hole though the turret of a tank with a high velocity AP round, the friction resulting from the high velocity round passing through the steel turret is going to create thousands of globs of molten steel. This often would ignite the ammunition magazine in the turret and thus blow the turret off the tank. Concentrated fire on the tracks of a tank or half track would often sever or damage a track link. If the vehicle then attempts to get underway, the track binds up and shreds itself. In essence, you make the vehicle destroy itself by introducing failure with concentrated localized damage. The P-38 was great at this because of its tightly grouped gun battery.

>No matter where the stream hit, serious structural damage was a result. Engine, wingroot, outer wing panel, cockpit, rear fuselage, tail--it didn't really matter.

Do you have a source on that?

That's not a direct quote from a print or web source. It's my own statement based on a combination of things, those being, mainly, episodes of Discovery Wings over the years with many pilot interviews, and videos of static tests of the P-38 gun battery against 1/2" steel plate and some airframes at various distances and angles, conducted by the USAAC. If a P-38 missed, it missed. But when it hit, it literally shredded the area it hit because of the tight grouping of the guns and the resulting large amount of ammo penetrating a small area on the target. I've also seen video of similar tests conducted on the "gun trucks" of the Vietnam war era. The gun spacing of the quad .50 turret in these trucks was a little wider than that of the P-38 gun battery, but the effect was very similar. Obviously the damage wasn't quite as extensive without the Hispano. Nonetheless, the gun truck quad .50 would also shred 1/2" steel plate out to 300 yards with few deflections even up to very steep off angle shots. At 70 degrees off angle, the number of ricochet rounds started increasing quite a bit. Keep in mind this is flat 1/2" steel plate. There are only 3 locations where this would be found on a fighter airframe (and it wouldn't be completely flat). These would be around the cockpit sides and floor, possibly around the fuel tank behind the cockpit in the rear fuselage, and under the engine cowling or bolted to the engine cradle. The .50 Browning, as with most .50 ammo of WWII from any nation, had zero problems penetrating the aluminum skin of any aircraft, and still had plenty of energy left to damage internal aluminum structural members, or to penetrate steel armor plate under the skin. The AP and standard 'ball' ammo of the 20mm was even more effective here. The reason the .50 Browning was more effective in the P-38 than many other US fighters mounting the same gun is the concentration of so many .50 projectiles in a confined area on the target. There's nothing magic about this, just simple physics. And, again, given the penetration power of the .50 BMG round, 10 to 20 of these rounds, combined with a couple of 20mm Hispano rounds into the same area, was often enough to destroy a wing spar or fuselage bulkhead causing structural failure of the airframe. The result was a wing or tail coming off the airplane due to the aircraft's speed and G load. If the cockpit area was hit, the armor plate was of little value and the .50s and 20mm would go right through it killing the pilot. Hits to the engine cowling would easily penetrate the steel armor plate and have sufficient kinetic energy remaining to damage the intake tubing, oil cooler lines and fuel lines. After the first few rounds weakened the armor plate, those following in flight would likely penetrate the engine block, igniting the fuel and oil in the engine manifold and oil passages. Add in a single hit from an AP round from the Hispno and the engine is toast in one hit, regardless of armor plate.

>This also would have yielded a cyclic battery rate of about 106 rounds/sec (assuming 800 rds/sec per gun) firing in a spread of about 2 ft x 3 ft.

Since you are new to this thread, please check out the paragraph on the "shotgun misunderstanding" above.

I've read the entire thread. I'm not sure what you're getting at here. I'm estimating that pattern as I don't know what the actual barrel spacing was on the 8 gun P-38. Obviously as the guns heat up you're going to get some fliers running around, and you'll have some variance from one gun to another, as with all aircraft. I'm not familiar with the sighting/alignment procedures the ground crews used to zero the P-38 guns. I can tell you that in the gun test videos I saw, the pattern on target was pretty darn tight.

 

[HoHun]

Hi Hardwarefreak,

>The British Purchasing Commission received 'castrated Lightnings' [...]

Their negative comment was the result of a test of a standard Lightning as flown by the USAAF though, and thus applies to P-38s as flown by the USAAF as well.

>And yes, those GIFs are kinda neat. I'm not sure how accurate they are, but they give an excellent graphical understanding of static trajectory.

Well, dig out some data and check the trajectories for yourself if you doubt. We can only learn from it ...

>Unfortunately, most aircraft that were being fired upon were likely making evasive maneuvers.

What's your source on that?

>The P-38 was great at this because of its tightly grouped gun battery.

The gun battery was "tightly grouped", but it was neither particular powerful nor did it have a particularly narrow cone of fire.

Here is the firepower comparison again:

Me 262: 20,1 MW
Fw 190A-8/R2: 13 MW
Ta 152H: 7,6 MW
Fw 190A-8: 5,5 MW
Me 109K-4: 5,5 MW
Beaufighter Mk 21: 5,3 MW
...
P-47D: 2,3 MW
P-38: 2,2 MW

These 2.2 MW at 300 m range impact over an area of more than 2.5 m^2, giving an average of less than 0.9 MW/m^2 firepower density.

At the same range, the nose guns of the Me 109K-4 impact in a pattern of about 1 m^2 area, giving an average firepower density of more than 5 MW/m^2.

>It's my own statement based on a combination of things, those being, mainly, episodes of Discovery Wings over the years with many pilot interviews [...]

I see.

>The .50 Browning, as with most .50 ammo of WWII from any nation, had zero problems penetrating the aluminum skin of any aircraft, and still had plenty of energy left to damage internal aluminum structural members, or to penetrate steel armor plate under the skin.

I guess you missed this information, posted earlier in this thread:

A report on the Fw 190A-3 prepared by the Oxfordness Research station concludes that in an astern attack, neither 20 mm H.S. A.P., 20 mm H.E./T. (Fuze 253) nor 20 mm S.A.P./I. were able to penetrate the Fw 190's pilot armour when fired from a 10 degree sector after of the plane. The deflection of the projectiles by the aircraft skin and - when it came to the head armour - by the vertical tail was enough to reduce their penetration abilities to a fraction of the nominal value. It was not possible for any of the rounds (including 0.5" A.P.) to penetrate the engine cowling and damage the engine in this type of attack.

With regard to the fuel tanks, the effect you mention is specially stressed:

"The angle of the fuselage with this line of attack is 6 degrees and this gives 0.303" B. Mk.VIII and 0.5" B. Mk.II no chance of causing a fire. These ammunitions will for the most part be deflected or broken up on the 19 s.w.g. fuselage skin; larger angles off tail would make these ammunitions more effective. The detonation of 20 mm. H.E./I. on, or just after, passing through the skin also minimises its chances of producing a fire unless the strike is within 3' of the tank compartment bulkhead."

In fact, 20 mm H.E./I. and S.A.P./I. were the only incendiaries that could damage the tanks at all: "The smaller calibre incendiary ammunitions will either be broken up or deflected away before reaching the fuel tanks."

The RAF definitely had good reasons to leap-frog from 7.7 mm machine guns to 20 mm cannon, skipping the intermediate 12.7 mm calibre. The effectiveness of heavy machine guns for air-to-air combat was not what popular perception today would imagine ...

>>This also would have yielded a cyclic battery rate of about 106 rounds/sec (assuming 800 rds/sec per gun) firing in a spread of about 2 ft x 3 ft.

>I've read the entire thread. I'm not sure what you're getting at here.

It not the number of projectiles that makes a battery destructive, it is (unsurprisingly) the destructiveness of the projectiles that makes a battery destructive.

Regards,

Henning (HoHun)

 

[HoHun]

Hi Kurfürst,

>Would it be too much to ask for a similiar animated GIF for the Bf 109G, with MG 151/20 or MK 108 central gun, and gunpods?

Here is another Messerschmitt for you, the Me 109F-1 with MG 151 in 15 mm and the 7.92 mm cowl guns. Some (very slight) inaccuracy in the cowl gun trajectories result from having to re-calculate the original trajectory data from the standard bullet to the "improved" bullet of higher muzzle velocity that was used in the MG 17.

Regards,

Henning (HoHun)

 

[Clay_Allison]

I have read that there were experimental P-38 field installations of 8 .50s in the nose with the Hispano removed. If the additional 4 guns also had 500 rds each that would be a total of 4000 rds of .50 cal per sortie. This also would have yielded a cyclic battery rate of about 106 rounds/sec (assuming 800 rds/sec per gun) firing in a spread of about 2 ft x 3 ft. The article I read didn't go into detail, but I'm guessing that, sadly, these 'gunship' P-38s were likely used mostly for ground attack in the Pacific theater. Oh, but what an awesome air-air gun battery this would have been. The firepower of a P-47 all packed tightly into the nose. If the weight of those extra 4 Brownings and the additional ammo didn't completely unbalance the aircraft, and it could still dogfight, my oh my what a predator this 8 gun P-38 would have been.

I've often thought that an 8-gun nose armament on the P-38 would be the ultimate allied air-to-air gun grouping for the Pacific Theater.

 

[drgondog]

Hi Hardwarefreak,

>A report on the Fw 190A-3 prepared by the Oxfordness Research station concludes that in an astern attack, neither 20 mm H.S. A.P., 20 mm H.E./T. (Fuze 253) nor 20 mm S.A.P./I. were able to penetrate the Fw 190's pilot armour when fired from a 10 degree sector after of the plane. The deflection of the projectiles by the aircraft skin and - when it came to the head armour - by the vertical tail was enough to reduce their penetration abilities to a fraction of the nominal value. It was not possible for any of the rounds (including 0.5" A.P.) to penetrate the engine cowling and damage the engine in this type of attack.

With regard to the fuel tanks, the effect you mention is specially stressed:

"The angle of the fuselage with this line of attack is 6 degrees and this gives 0.303" B. Mk.VIII and 0.5" B. Mk.II no chance of causing a fire. These ammunitions will for the most part be deflected or broken up on the 19 s.w.g. fuselage skin; larger angles off tail would make these ammunitions more effective. The detonation of 20 mm. H.E./I. on, or just after, passing through the skin also minimises its chances of producing a fire unless the strike is within 3' of the tank compartment bulkhead."

What caused all the explosions in the fuselages of 109s and 190s when hit by .50 API? Pilot carelessness in lighting cigarettes while being shot down?

In fact, 20 mm H.E./I. and S.A.P./I. were the only incendiaries that could damage the tanks at all: "The smaller calibre incendiary ammunitions will either be broken up or deflected away before reaching the fuel tanks."

The RAF definitely had good reasons to leap-frog from 7.7 mm machine guns to 20 mm cannon, skipping the intermediate 12.7 mm calibre. The effectiveness of heavy machine guns for air-to-air combat was not what popular perception today would imagine ...
>


Regards,

Henning (HoHun)

Makes one wonder if the same testing facility also concluded that .50 API would also be worthless for strafing German aircraft on the ground as well as worthless against locomotives, road and barge vehicles.

What a crock!

 

[KrazyKraut]

Since armor protection layout seems to be arranged to protect from 6 o'clock and 12 o'clock on most WW2 fighters I'm not surprised it doesn't protect well against strafing aircraft.

 

[drgondog]

Since armor protection layout seems to be arranged to protect from 6 o'clock and 12 o'clock on most WW2 fighters I'm not surprised it doesn't protect well against strafing aircraft.

KK - when a battery of .50s perforate the steel hulls of barges, trucks, light armor and locomotive outer hull and boilers - it would be 'stretching' to conclude that they can't punch through aluminum skin, bulkheads, wing spars and engine blocks, or somehow is easily deflected by .032-.040 skin before smashing into a fuel tank.

Huey skins are typically in that range and I GUARANTEE you that 7.62x39 will punch the crap out of them from any deflection angle. Please do not suggest to me that the 12.7 or .50 is somehow on the same par as that little bitch in air combat or ground to air..

How much combat film have you seen where a 109 or 190 simply lights up, then blows up from shallow deflection shots - granted not an extremely high percentage - but there is also the classic scene where the a/c simply rolls off in a shallow dive or roll and continues straight into the ground, a stitching into the engine with a resulting huge stream of coolant and/or steam from smashed engine block.

It is just silly to postulate that 4 or six or 8 .50's were 'ineffective' when those weapons accounted for most of the Allied air and ground scores.

That is my one and only point - not that .50 API is more destructive than the 20mm.

 

[slaterat]

Dragon

Remember those RAF tests were at an angle of 10 degrees or less. At angles greater than that the ability of the skin to deflect rounds greatly decreases.

Also without having the actual testing procedures in front of us the results could be quite questionable. The RAF firing trials that I have read almost all
have been based on single shots fired, not on bursts from a single or multiple gun battery. Of course this could give quite different results.

Slaterat

 

[drgondog]

Dragon

Remember those RAF tests were at an angle of 10 degrees or less. At angles greater than that the ability of the skin to deflect rounds greatly decreases.

Also without having the actual testing procedures in front of us the results could be quite questionable. The RAF firing trials that I have read almost all
have been based on single shots fired, not on bursts from a single or multiple gun battery. Of course this could give quite different results.

Slaterat

SlateRat - I remember.

However, the ability of .032-.040 aluminum shear panels to cause 'deflections' and richochet's for .5 API is greatly overstated in this thread.

 

[HardwareFreak]

I have a vivid memory of P-38 gun camera footage in which the pilot fires a very short burst into the nose of a Bf 109 from about 100-150 yards, 40 degrees or so off angle. The P-38 is behind the Bf 109 and to the right, firing into the right side of the nose. There are 10 or so small orange'ish impact flashes on the engine cowling directly behind the prop, the spread being no greater than 2 feet across (right to left) and maybe a foot in height. All the impact flashes were the same size, meaning he wasn't firing the cannon, just the Brownings. Almost instantly, the prop stops turning and fire and smoke start pouring out of the rear of the cowling right in front of the cockpit, as the Bf 109 slows rapidly and noses over out of control. I'm sure others have seen this same footage. It seems to be pretty popular footage for any TV program covering WWII air combat.

This one piece of footage demonstrates pretty dramatically the effectiveness of a 4 x .50 nose battery. One quick well aimed burst disabled a Benz DB601/5 behind thin armor plate, albeit at fairly close range. The effect at 300 yards would have been the same, although a bit more pilot skill would have been needed to pull off the longer range single burst kill of the engine.

 

[HardwareFreak]

It not the number of projectiles that makes a battery destructive, it is (unsurprisingly) the destructiveness of the projectiles that makes a battery destructive.

Half of your posts I've read are fairly informative. Then you fire off statements like this, which are 180 degrees opposite of combat experience through two world wars and numerous conflicts since...

How can you state something like this with a straight face? Are you trolling?

You quoted "weight of fire" figures in the same post for pity sake. A critical component of weight of fire calculations *IS* the number of projectiles fired!

You contradicted yourself in the same post my friend.

 

[HoHun]

Hi Hardwarefreak,

>>It not the number of projectiles that makes a battery destructive, it is (unsurprisingly) the destructiveness of the projectiles that makes a battery destructive.

>Half of your posts I've read are fairly informative. Then you fire off statements like this, which are 180 degrees opposite of combat experience through two world wars and numerous conflicts since...

Assuming to your favour that you are victim of a genuine misunderstanding, here is the full quote from the post I referred you to:

"With regard to probabilities, what counts is only the product of the probability of a hit and the hit's probability of a kill."

Since you assured me that you have read the entire thread, I trusted on you to realize that the "destructiveness of the projectiles" is proportional to the product of number of rounds that hit and one hit's probability of a kill.

>How can you state something like this with a straight face? Are you trolling?

1) You don't know anything about my face

2) No.

3) And I don't consider a new account created exclusively for participating in a controversial thread a good basis to ask such question ...

>You quoted "weight of fire" figures in the same post for pity sake.

Which "same post" are you referring to? This looks like another misunderstanding ...

Regards,

Henning (HoHun)

 

[HardwareFreak]

Hi Hardwarefreak,

3) And I don't consider a new account created exclusively for participating in a controversial thread a good basis to ask such question ...

That is a ginormous, and incorrect, assumption to make. This is my first and only account on this site, and until very recently (within the last week) I didn't know this site existed.

Which "same post" are you referring to? This looks like another misunderstanding ...

This is what I was referring to, from #307:

Here is the firepower comparison again:

Me 262: 20,1 MW
Fw 190A-8/R2: 13 MW
Ta 152H: 7,6 MW
Fw 190A-8: 5,5 MW
Me 109K-4: 5,5 MW
Beaufighter Mk 21: 5,3 MW
...
P-47D: 2,3 MW
P-38: 2,2 MW

It not the number of projectiles that makes a battery destructive, it is (unsurprisingly) the destructiveness of the projectiles that makes a battery destructive.

The point I was making is that those very firepower figures you pasted include within them the combined rate of fire of the aircraft's gun batteries, as well as many others qualities, including explosive shell power, penetration factor, etc.

It's not my intention to beat you up and make this a 10 page argument. All I'm saying is that you contradicted yourself. Obviously unintentionally, but nonetheless, you did. You have corrected yourself in your post immediately above when you state that "number of rounds that hit" is a factor. This obviously isn't an absolute as a "lucky" shot to a critical location, say a pilot's head, doesn't rely upon multiple rounds for a kill. This is obviously a very rare exception. The majority of aerial kills were the result of multiple hits on the target, and in the absence of those multiple hits, would not have been kills.

 

[HoHun]

Hi Hardwarefreak,

>>And I don't consider a new account created exclusively for participating in a controversial thread a good basis to ask such question ...

>That is a ginormous, and incorrect, assumption to make.

5 posts in total, all in this thread, account created well after this discussion started, claiming to have read all of the thread ... that's the data I have on you.

And you accused me of trolling in your post #4 ... how about an apology now that I have corrected your misunderstanding?

I might be guilty of using a less than perfect formulation, but I can hardly think of a more offensive way of asking for clarification than the one you chose.

>This is what I was referring to, from #307:

Your misunderstanding again - Watt is power, not weight.

>All I'm saying is that you contradicted yourself.

Your personal misunderstanding contradicted what seems to be an otherwise OK understanding of my posts ... you should have realized that after I posted my clarification.

Kind regards,

Henning (HoHun)

 

[Clay_Allison]

Hi Hardwarefreak,

>>And I don't consider a new account created exclusively for participating in a controversial thread a good basis to ask such question ...

>That is a ginormous, and incorrect, assumption to make.

5 posts in total, all in this thread, account created well after this discussion started, claiming to have read all of the thread ... that's the data I have on you.

And you accused me of trolling in your post #4 ... how about an apology now that I have corrected your misunderstanding?

I might be guilty of using a less than perfect formulation, but I can hardly think of a more offensive way of asking for clarification than the one you chose.

>This is what I was referring to, from #307:

Your misunderstanding again - Watt is power, not weight.

>All I'm saying is that you contradicted yourself.

Your personal misunderstanding contradicted what seems to be an otherwise OK understanding of my posts ... you should have realized that after I posted my clarification.

Kind regards,

Henning (HoHun)

I like your style, really. But I have to say that I know far more about guns than I do about aircraft, and I know that with a multitude of impacts each successive one is more damaging than the first, especially when hitting in rapid succession and creating a "stacking" effect of energy transfer. How many hits you can make is very important to how destructive any weapon is.