Author Topic: remember the ju88 13mm debate?.....  (Read 1144 times)

Offline Tony Williams

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remember the ju88 13mm debate?.....
« Reply #15 on: March 07, 2003, 08:30:16 PM »
Quote
Originally posted by HoHun

That poor little plane had a big big engine and could have carried the MK103s easily :-)
 


Oh, it could have flown in a straight line, I don't doubt. But when you consider that the MG 151/20 gunpods fitted to some Bf 109s were often removed because of the serious effect they had on combat handling, then factor in that the MG 151 weighed 42 kg while the MK 103 weighed 140 kg, and it isn't hard to imagine the result. The effect of the recoil on shooting accuracy would have been considerable, as well.

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Offline snafu

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How about a JU88P V1
« Reply #16 on: March 08, 2003, 03:35:56 AM »
Not trying to "Hijack" :)

How about a JU88P V1. It was basically a modified A4 but with a 75mm PaK 40L anti tank gun in an under fuselage fairing. with twin MG 81Z's looking after the rear. I know it was used against T-34s with some success.

Other variants of the "P" series were fitted with a pair of 37mm BK 3.7 Flak 18 cannons and later a 50mm BK 5 cannon. All saw service. Would make a nice alternative to the IL2.

TTFN
snafu

Offline HoHun

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remember the ju88 13mm debate?.....
« Reply #17 on: March 08, 2003, 06:41:55 AM »
Hi Tony,

>But when you consider that the MG 151/20 gunpods fitted to some Bf 109s were often removed because of the serious effect they had on combat handling

The gondola-equipped Me 109 remained in service in vast numbers, and in fact there were more dedicated bomber destroyer Me 109s in the Luftwaffe than dedicated bomber destroyer Fw 190s. I guess the stories about "removal" stem from the time when the Jagdgeschwader had to revert some Gruppen to air-superiority fighters when the 8th Air Force bombers starting bringing escort fighters.

The impact gondolas had on performance certainly was detrimental, but the K-4 had a much more powerful engine than the original G-6/R6 that was in service earlier. Still, there can be no doubt that internal wing armament was superior to gondolas, thus the plans to produce the K-6.

But to get back to your original point: You were talking about "getting off the ground", and that's a situation where 200 kg extra hardly matter at all :-)

Even the old Emil could lift off with a 500 kg bomb easily (though it wasn't cleared for that operationally as the bomb's fins almost scraped on the tarmac). Fighters simply have a lot of excess power, and the Me 109 (like the Spitfire) was almost a STOL aircraft if you compare it to monsters like the P-47 :-)

>The effect of the recoil on shooting accuracy would have been considerable, as well.

In fact, one of the reasons the MK108 didn't yield much to the MK103 with regard to accuracy was that it had a much smaller dispersion.

Regards,

Henning (HoHun)

Offline hazed-

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Re: Ju 88
« Reply #18 on: March 11, 2003, 03:26:09 AM »
Quote
Originally posted by Tony Williams


I regard Green as a rather dangerous source when it comes to armament, because he put in a lot of convincing detail, some of which was wrong. For example, in at least one book he stated as a fact that later models of the Bf 109 could be fitted with an MK 103 engine gun, MK 103s in underwing pods and 15mm MG 151 on the cowling, thereby scoring 0/3.

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Ok tony I have some information for you which you might find interesting.After reading this  can see the mk103 in any unmodified form would not be suitable for this proposed set up but I think i may have found something which would easily cause an error such as william green 'may' have made.

The Luftwaffe Fighter Force:A view from the cockpit' by Adolf Galland et al, Edited by David Isby ISBN 1-85367-327-7
on page 183 about Luftwaffe armaments:

'26.Weapons which are used with photo-electric cell firing.In the FW190 three MK103 rocket tubes with a single shot each pointing upward at 70-80 degrees were fired by photo-electric cell when flying under the bomber formation.'

as you can see this weapon if used on the late 109s could easily be assumed to be the typically mounted weapons when in fact they are a very different weapon.could this be the reason william green made the assumption the MK103 was used on the 109-K?

also i wasnt sure if you was of the opinion the MK103 wasnt used in Gondala form because of the weight of the weapon but it seems they were used on the FW190s at least (hs-129 was another)
Page 184
'4.FW190. 2xMK 103 under wing armaments with about 40 rounds each, in addition to 2xMK 151 and 2xMG17. Tested in a few models.
Advantages:High speed muzzle velocity, great range, and good fire effect.
Disadvantages:Speed loss of 60 km/h, aircraft not stable while firing,lowering of ceiling and reduction in manouverability.The aircraft was over-loaded with this armament.'


like i said i wasnt sure whether you meant that they(MK103s) were never tried as gondalas or that they were just unsuitablefor the 109 in particular(?) .As you can see they obviously tried some "way out" loadouts and im inclined to believe they would have at least tried some of these weapons(MK103#'s) on the later 109s,be they the gondalas, the engine mounted MK103m or the 3 single shot MK103s, although i'd suspect they were rejected much like this FW190 idea, I think its very narrow sighted to disregard possible testing that may have been done because one author (Manfried Griehl's) fails to mention it.I realise hes a good author but all historians are faced with the same problem, they very rarely get to see every document ever written during the war on a particular aircraft, often their scope is so big they make quite a few mistakes, like Green has it seems.With this in mind I'm not ready to agree with you fully that these loadouts were never tried or ever used.I do agree from what you have said it would seem a very unlikely combination and more a danger to the pilot of the poor 109 than any targeted bomber! :) but you just cant use 'common sense' with the LW to decide if you beleive in a particularly strange sounding loadout, I mean these are the guys who put 75mm PAK guns in aircraft and used crazy ideas like 10kg bombs slung on 300 foot cables and even Detonating cords on parachutes and even liquid and powdered materials to cloud windscreens and clog engines!
These boys were real loons! :D

just one last quote from the same book:
page 186
'19.Me410. 2xMK103 and 2xMG151 built into the fuselage.Produced as the factory built armament of some Me410s.Not used in the defence of the reich because by the time it was ready, the Me410 had to be withdrawn from operations'

these are just some of the 35 odd loadouts in this list.They are taken from Interrogations of Generalleutnant Galland, Oberleutnant Bar,Oberstleutnant Dahl and Oberst Peterson at Kaufbeuren Germany 12-14 September 1945.

Erprobungskommando 25, set up for the purpose of testing proposals of armements and loadouts would seem to be the place to investigate these claims of possible loadouts. I wonder if there are any records left about this group?. If I lived in Germany I think Id try to go find some info about them. Im tempted often to take a trip to the British public records office in Kent and i hope to go there one day soon, I wonder if theres anyone in Germany who has access to a similar source of records and could go look for information on WW2 armement?

for now I would agree, the 109K-6 was unlikely to have been fitted with 3 MK103 in the configeration William Green describes, However, there is the Engine mounted MK 103m which would explain the quote about difficulty the ground crews had with the barrel and theres a fair chance at some point the LW tried the 3xMK103 single shot 70-80 degree firing version on a 109 and its obvious they had MK103 gondalas and had tried them on almost any aircraft they felt could carry them. Do you suppose they never tried them on their most powerfull 109 to date? Judging by the many crazy configurations they did try, I feel its highly probable they indeed did try some of the more unreasonable sounding setups, even possibly the 109K-8 with MK103m engine mounted 30mm and 2 underwing MK103 gondalas. Maybe after the first flight they dismissed it outright? who knows? I just dont agree with the dismissal of the idea that they might have tried it, not unless theres firm evidence the armament simply couldnt 'fit'. I wouldnt agree to seeing these loadouts in AH of course, Im still of the opinion if it wasnt in use in combat , on a fairly regular basis it shouldnt be put in a simulator of WW2.

After seeing the MK103M or Mot comments and others from hohun concerning the 109K-8 (proposed production fighter) and considering in order to propose a model there were usually tests of some kind performed in order to see if the proposal is a worthy one I have decided to rescore poor old William Green,

he scores one and a half out of 3 ;).One for the fact there were indeed MK103 underwing gomdalas available and half a point for claiming a 109 had a MK103 cannon when in fact it seems more likely it was the MK103M.The MG151/15's are obviously wrong if it can be proved those guns couldnt fit in the cowl of a 109K and so scores zero :).

Better than 0/3 eh? :)
« Last Edit: March 11, 2003, 05:46:05 AM by hazed- »

Offline butch2k

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remember the ju88 13mm debate?.....
« Reply #19 on: March 11, 2003, 04:18:34 AM »
Hohun K-4/R6 was not a bogus designation, but just the correct designation for the R6 rustzustand and not for the R6 rustsatze.
The K-4/R6 like the G-10/R6 was equipped with bad weather flight equipment.
When authors will understand that /R6 and Rustsatz 6 are very different things, life will be much simpler. And as you mentionned the Rustsatz IV was the MG151/20 gondolas for the K-4.

Btw note that the K-4 was the only one to be cleared for 500kg bombs (the G-10 wasn't).

As for the MK103 in 109 wings, i do not put much faith on it since it would have required some rebuild of the wing like the MK108 installation, moreover recoil would have had very negative effect on accuracy.

Offline hazed-

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remember the ju88 13mm debate?.....
« Reply #20 on: March 11, 2003, 06:21:23 AM »
Quote
Originally posted by butch2k
As for the MK103 in 109 wings, i do not put much faith on it since it would have required some rebuild of the wing like the MK108 installation, moreover recoil would have had very negative effect on accuracy.


I re-read Williams greens description of the 109K-4 and K-6 and he nowhere mentions wingmounted MK103s (in the sense of internally mounted) he only mentions , and i quote:

''Later production Bf 109K-4s introduced an engine mounted 30-mm MK 103 cannon in place of the standard MK108, but the 2.5-in diameter outer sheath enclosing the barrel of thisweapon rendered a barrel change under operational conditions a somewhat onerous task.The MK103 was also adopted for the next K series variant, the bf 109K-6, which, intended primarily as an anti-bomber weapon, carried two additional MK 103 cannon in underwing gondolas, but reverted to 13-mm MG 131 in place of the 15mm MG151s in the engine cowling'

Interestingly it further adds tony and ho hun,

'Deliveries of the 109K-6 to the jagdgruppen began in january 1945, but relatively few had attained operational status by the time the third Reich finally collapsed, and with a loaded weight of 7,928lb and somewhat unweildy in consequence, this was perhaps fortunate for the jagdflieger operating under conditions of complete allied air supremacy.'

so time to calculate the approximate weight of the MK103 combo isnt it? :D

if the approximate weight of a 109K-6 with 2xMG131+1xMK103 comes in under 7,928lb then you add the guessed weight of 2 underwing MK103 gondolas, (you said 'the MK 103 weighed 140 kg' then add weight of gondola housing/mounts etc) and you arrive at this huge weight of 7,928 lb maybe it will cause a rethink on just whether william Green was wrong?

(examples :
 bf 109G-2 weight:Empty,4,968lb; empty equipped,5,687lb; normal loaded,6,834lb; maximum,7,055lb
 bf 109K-4 weight:Loaded clean,6,834lb; Maximum,7,475lb)

I leave it to you ...... ;)
« Last Edit: March 11, 2003, 06:32:48 AM by hazed- »

Offline butch2k

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remember the ju88 13mm debate?.....
« Reply #21 on: March 11, 2003, 06:51:36 AM »
I won't put much faith in Green's work, a lot of what he has written on the 109 i was unable to corroborate or found totaly wrong... just consider the cowling MG151 for instance...

I never thought of internally mounted MK103 as they simply do not fit in, but i considered gondolas akin to the one used for the MK108 on the Gustav. The later required the wing to re-inforced to absorb the recoil generated.

Offline Tony Williams

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Mk 103
« Reply #22 on: March 11, 2003, 07:48:43 AM »
I never said that there weren't such things as podded underwing MK 103s - the Fw 190 installation is well known (as is the fact that it was a failure and not used in service) - nor did I say that the MK 103M wasn't tried in a 109K - as there is one reasonably reliable account that it was - once.

All I said was that Green's statement that late model 109s were fitted with this armament (implying that it was more than just an experimental test), as well as cowling-mounted MG 151s, was incorrect on the best available evidence, and I stand by that. It's still 0/3 as far as I'm concerned!

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Offline MiloMorai

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Re: Ju 88
« Reply #23 on: March 11, 2003, 11:24:33 AM »
Quote
Originally posted by Tony Williams
I regard Green as a rather dangerous source when it comes to armament, because he put in a lot of convincing detail, some of which was wrong. For example, in at least one book he stated as a fact that later models of the Bf 109 could be fitted with an MK 103 engine gun, MK 103s in underwing pods and 15mm MG 151 on the cowling, thereby scoring 0/3.

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Glad to see your statement Tony, for it confirms a statement I made in another thread about being careful with what Green says.:)

The cowl of the K-4 was no higher than the bulged cowlings of the other Me109s, only more streamlined.
« Last Edit: March 11, 2003, 11:32:13 AM by MiloMorai »

Offline HoHun

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remember the ju88 13mm debate?.....
« Reply #24 on: March 11, 2003, 11:38:57 AM »
Hi Butch,

>When authors will understand that /R6 and Rustsatz 6 are very different things, life will be much simpler.

I'll have to start by understanding that myself :-)

>And as you mentionned the Rustsatz IV was the MG151/20 gondolas for the K-4.

So was the Luftwaffe correct in calling the gondola-equipped K-4 variant K-4/R6?

>Btw note that the K-4 was the only one to be cleared for 500kg bombs (the G-10 wasn't).

Highly interesting! I didn't know any of the Me 109s was actually cleared for operational use of such a big bomb.

>As for the MK103 in 109 wings, i do not put much faith on it since it would have required some rebuild of the wing like the MK108 installation, moreover recoil would have had very negative effect on accuracy.

The MK103 would never have fit into the wings (I believe, without checking it :-) The MK108 were much superior weapons anyhow - all the MK103 had in its favour was muzzle velocity, the MK108 was better in almost everything else.

Regards,

Henning (HoHun)

Offline HoHun

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« Reply #25 on: March 11, 2003, 12:07:15 PM »
Hi Hazed,

>'Deliveries of the 109K-6 to the jagdgruppen began in january 1945

Griehl quotes Luftwaffe order OKL Führungsstab Nr. 937/45 gKdos op from 8.2.1945, quoting the current aircraft equipment of the Me 109 groups as:

10 groups Me 109G-10
07 groups Me 109G-14
01 group_ Me 109G-14/AS
02 groups Me 109G-14/U4
10 groups Me 109K-4

There are no K-6 groups mentioned. Even more importantly, even the planning for summer 1945 doesn't mention the K-6, but only a uniform equipent with K-4 and K-4/R6 fighters.

A similar order from 30.03.1945 finally mentions the K-6, but - as the Me K-4/R6 - only as planned equipement, not as current equipment.

The conclusion is obvious: In February 1945, the K-6 had not even entered Luftwaffe planning. In March, the K-6 was expected to come in, but probably only in the long term as the inferior K-4/R6 which wasn't available yet was still listed, too.

Besides, even the listing of the K-6 doesn't mean it was equipped with MK103 wing cannon - according to a 1944 Messerschmitt drawing reprinted in Griehl's book, it was to carry 3 x MK108 + 2 x MG131.

The weight of 7928 lbs you quote are 3600 kg, which matches a standard Me 109K-4 with drop tank nicely. A P-51D flying over the Reich would weigh around 4000 kg without its drop tanks, so this is nothing to write home about.

Regards,

Henning (HoHun)