How did the Rüstsatz system work?
 

We all know about the Rüstsätze kits, the prepackaged field modification kits that usually came direct from the aircraft manufacturer. But how did the system work?

1) Was there a catalog to choose and order from? (And did the cost of the kits come out of the unit's budget?)

2) Who had the authority to order them? Staffelkapitan? Gruppenkommandeur? Geschwaderkommodore?

3) Also, on a related question, who had the authority to delete the outboard 20mm wing cannon (and later 30mm) on the Fw-190? I've read that certain Experten had the outboard weaponry deleted off their aircraft for reasons of weight and safety. (I've seen the safety part--repeatedly--in gun camera film. Hits to the outer wing of a cannon-armed Fw-190 would often detonate the cannon ammunition box, being armored or not, and the wing separates dramatically at that location. Example of this, the .42 -.48 second mark in this gun camera film: https://www.youtube.com/watch?v=tHKj3CZK3WY

Bronc

Re: How did the Rüstsatz system work?
 

Hello,

That's some very interesting questions that I can't help you with but something caught my attention :

What's the source of the point that the Rüstzustand 8 equiped Fw 190s were plagued by the same issue as the Rüstzustand 2 equiped Fw 190s that this factory modification was designed to overcome ? Fw 190 A-8/R8 were delivered very lately (November or December 1944 I think, correct me if it's a wrong assumption) and no longer after the Sturmgruppen operations, if not stopped, were very limited.

Regards

Alfred

Re: How did the Rüstsatz system work?
 

Greetings Alfred,

The Maru Mechanic, No. 50, Bf109/Fw190 (1985) provides shocking clarity in this matter. On page 93, is an illustration of the cannon ammunition protection upgrade of the A-8/R8. The armor was comprised of a 4mm top plate, a 4mm bottom plate, and a 20mm face plate. No rearward protection was included. Furthermore, the 4mm top and bottom plates were TOTALLY ineffective against the .50-cal. armor-penetrating/armor-penetrating-incendiary ammunition used by USAAF aircraft. (I've personally witnessed .50-cal. armor penetrating rounds pierce 40mm of steel armor plate at 500 meters.)

Defensively, the R8 cannon ammunition protection "upgrade" was a disaster. No rearward protection was provided, and the top and bottom protection was totally ineffective. Even the face plate, being 20mm, was marginal protection. And all of it added weight.

The installation of cannon, and high explosive 20mm and 30mm ammunition boxes in the outboard stations of the Fw-190 killed A LOT of pilots. The boxes could not be properly protected, and a hit in the box detonated the entire box. It was like a box of dynamite going off in the wing.

Bronc

Re: How did the Rüstsatz system work?
 

Installation of cannon in the wing was normal on a great many WW2 fighters, and were generally omitted, once the choice became available, for reasons of agility rather than safety. Or at least, I don't recall ever encountering this argument before. A direct hit on a box of ammunition is unlikely to be any kinder to an aircraft wherever it is placed.

As for there being "A LOT" - great emphasis noted - of losses from this cause, could some actual numbers be produced to back this up? How did it compare with losses from other causes such as hits to the pilot or engine?

Re: How did the Rüstsatz system work?
 

That's make sense but we can wonder what was thinking the design team... (and why the validation team, if there was one, let this to modification to be added to the production lines). The most likely case would be a shot from above with an angle and the least in front.

Re: How did the Rüstsatz system work?
 

mmmmmmmmmmm...I am not sure if the unit could really "order" anything.

As standard, every aircraft built had the ability to carry every mod. available...even when the Rüstzustand mod. was not installed at factory level. This gave the option of the install any and all of the Rüstsatz equipment at field level

But...

As mentioned above, many of the factory installed R equipment (R1, R2, R3, R6, etc.) was removed...albeit usually due to the lack of performance that was a result of the installation. So in the end, there were a lot of parts and equipment laying around.

The field installed equipment (RI, RII, RII, RVI, etc.) I suspect was maybe just the units way of re-installing the already removed equipment that was on-hand?

I believe 99% of all photos that show the attached equipment are all factory mods, as opposed to the unit deciding to affix something on their own...

I have never seen any reports or requests for Rustsatz Kits...nor any documents mentioning the aircraft with a RII, as opposed to an R2...but this is not my field of expertise...sadly.

Re: How did the Rüstsatz system work?
 

Hello Graham,

A direct hit into a box of ball ammunition doesn't do anything. Even an explosive shell detonating in a box of ball ammunition fails to produce a secondary explosion. (I know these things to be facts because I've personally observed them. A hit to a box of ball ammunition just scatters ammunition all around. The propellant in cased ammunition is not explosive, but the PETN in a Minengeschoß certainly is.) And when a .50-cal. round hit a PETN-armed shell it detonated it, and that detonation produced a sympathetic detonation of the entire box. Watch the video again, it's quite obvious.

The 'A LOT' emphasis comes from watching a lot of gun camera film. It happened A LOT. And, as opposed to a hit in the engine, the aircraft went cartwheeling out of the sky, making it v-e-r-y difficult to get out of.

harrison987 wrote,

"I am not sure if the unit could really "order" anything. [...]

As mentioned above, many of the factory installed R equipment (R1, R2, R3, R6, etc.) was removed...albeit usually due to the lack of performance that was a result of the installation. So in the end, there were a lot of parts and equipment laying around.

The field installed equipment (RI, RII, RII, RVI, etc.) I suspect was maybe just the units way of re-installing the already removed equipment that was on-hand? [...]

I have never seen any reports or requests for Rustsatz Kits...nor any documents mentioning the aircraft with a RII, as opposed to an R2...but this is not my field of expertise...sadly."

I really wish you expand on all of this. Any additional insight would be valuable. Information on the technical and logistical part of the game is hard to come by, at least for me.

Bronc

Re: How did the Rüstsatz system work?
 

Well...

Every aircraft had the ability to mount the Rüstzustand...that is, ALL the equipment installed at factory level. Not to be confused with the Rüstsätze sets, as those are the field mods.

A basic Me109 G6 that left factory AS a basic Me109 G6, had ALL electrical components and fittings in the wings to mount gondolas, fuel tanks...and inside the fuselage had the necessary connections to mount the ZBK241 bomb battery relay box...as well as the two mounts to attach either a drop tank or the bomb rack.

There are in-fact two DIFFERENT systems.

So when you see a Data Plate or Record indicating for example:

Me109 G6/R3

This was a a Factory-Made Me109 with 2 under-wing drop tanks for long range. It was delivered TO the unit in that configuration, drop tanks installed and all.

This is not to be confused with:

Me109 G6/RIII

Which is in-fact a field-mod Me109 that had a a single rack for one fuselage drop tank (300 L).

So if one took the basic Me109 G6 I mentioned above, and then added the drop tank...it then became an Me109 G6/RIII....and NOT a G6/R3...as the factory designation was different.

Some older books are mixing and matching the two...claiming the G6/R3 was the single belly mounted tank...when this is not correct.

And then people mis-ID in photos.

It is a confusing system with many irregularities.

Re: How did the Rüstsatz system work?
 

Adding a Rüstsatz to a Bf 109 did not change the designation.
The G-6/R3 was a long-range recon bird with reduced armament (just cannon).
A standard 109G had no equipment installed to support underwing drop tanks.

Re: How did the Rüstsatz system work?
 

Back in 2012, Leo wrote the following about various Experten removing their outboard Fw-190 cannons:

Re: How did the Rüstsatz system work?
 

An aviation expert from Florida says that only A-5 and earlier Fw190s could have the outer guns removed. His reasoning for A-6 and later Fw190s is that this was not an authorized loadout and would upset the CG of the a/c.

Re: How did the Rüstsatz system work?
 

That is what I said.

The Rüstsatz "field" kits were labelled with the letter "R" and a Roman numeral...as opposed to the Arabic Numeral. It also did not alter the the aircraft type. So an Me109 G-6 with Rüstsatz II (50 kg/110 lb bombs) remained an Me109 G-6 and not G-6/R2, which was a reconnaissance fighter with MW 50.

Adding the equipment in the field did not change it's "official" designation.

The underwing drop tanks were available from the G2 through the the G8. And there is at least one report mentioning a G6/R3 with wing drop tanks.

The G6/R3 designation you mention as only having a single cannon is not correct, as there are numerous photos of the G6/R3 with the dual MG131

As I said, it was a confusing system, and the same designations had different meanings for some of the models.

Re: How did the Rüstsatz system work?
 

Hello Bronc. Yes, a hit on a box of ball ammunition wouldn't have so much effect, but I never suggested that it would. That wasn't my point. Your argument was against wing-mounting cannon whereas the same explosive effect would occur wherever the box of cannon ammunition was placed.

You may well have seen a lot of such examples from camera film but you are still only describing your impression, not backing this with numbers.

What is impossible to judge is how the losses from such positioning compared with the losses or gains from any other design FW could have produced in the same timescale that placed the guns and their feed elsewhere. This couldn't be done without affecting other features of the design. The Russians did eventually manage to fit four cannon in the nose of their La 7, but this was a different, lighter, cannon, and would suffer from a reduction in firing rate due to synchronisation.

Re: How did the Rüstsatz system work?
 

Harrison987 is providing some much needed clarity, finally, as none of the published material (that I know of) provides it.

The question that I'm trying to get to--in a round about sort of way--is what were all the different ways that units were trying to adapt and cope by improving the performance of their aircraft in the field. And how much modification flexibility was the local, regional and high command structure affording those units. Removing all the unnecessary weight out the aircraft was critical, but who was making those choices and how were they authorized?

Bronc

Re: How did the Rüstsatz system work?
 

Dear harrison987,

Let me add my voice to those also learning from your information.

However, let me throw in a bit of confusion. I have seen or have a document somewhere that lists designations of R1, R2, etc. as they would apply to jet aircraft as a whole. I think it is a late war document. Yet, being familiar with the Me 262, this list doesn't match up with the actual configurations for the Me 262. The impression I got was that the list was an attempt at forming a uniform set of designations, but failed to take into account how the Me 262's were already identified. The list may have been a "flyer" created by someone who didn't understand the system, but has apparently been used by some authors to provide bogus Me 262 designations.

Add to this that basic aircraft configuration designations actually changed with time. For instance, Me 262A-1a was to be for purely fighter types with 4 MK 108's. Then the Me 262A-2a came along and this had only 2 MK 108 and 2 bomb racks. There then became a temporary designation for Me 262's equipped with 4 MK 108's and 2 bomb racks. Eventually, it was clearly decided to make this capability standard, meaning that the aircraft was capable of carrying bomb racks. This became the Me 262A-1a and the production of Me 262A-2a's was to be terminated.

As I have found with camouflage schemes, there were so many exceptions to supposed rules that the rules could, at best, be only used as a guide. David E. Brown has actually made a specialty of this, trying to determine which production site produced or which unit used which Me 262 based on that site's or unit's camouflage pattern.

Regards,
Richard

Re: How did the Rüstsatz system work?
 

Available yes but only in the specialized variants like /R3. Standard versions were not prepared to take them.
The MG ammo box space was supposed to be used for a 20 liter oil tank (per G-4/R3 manual) so either they changed something for the G-6/R3, these pictured guns were dummies or they weren't G-6/R3 aircraft.

Re: How did the Rüstsatz system work?
 

Perhaps a source to search for some material on the Rüstsatz system would be the CIOS reports. IIRC there is a detailed report that deals with the RLM/Luftwaffe system for aircraft modification and a copy of the report was available at USNA College Park.

Best Regards,

ArtieBob

How did the Rüstsatz system work?
 

Hi guys

Regarding the removal of the outer wing-mounted cannon on the Fw 190 A-series, it is true that according to the production sheets for the Fw 190 A-2 through A-5 this installation was optional and the MG FF/M cannons and their magazines and ammunition could be removed whereas the production sheets for the Fw 190 A-6 through A-9 describe the the MG 151/20E cannons as mandatory equipment and there is no mention of any possibility of removal. That being said, there is considerable photographic evidence that these weapons were occasionally removed and an example would be Fw 190 A-8 "White 13" (W.Nr. 171 747) that was being ferried by Johannes Kuhn of 3./Überführungsgruppe West to JG 26 at Brussels-Melsbroek when he decided to defect and belly-landed near Monkton in Kent on 30 August 1944. Another point of interest is that this aircraft was fitted with a BMW 801 TU engine. More about this Dutchman who served with the Luftwaffe can be found at http://www.stiwotforum.nl/viewtopic.php?t=8162

http://s32.postimg.org/n8bdbst9t/kuhn.jpg

Horrido!

Leo

Re: How did the Rüstsatz system work?
 

Hello Leo,

Slightly off topic, but regarding the engine of Fw 190 A-8, WNr. 171747, your comment that “this aircraft was fitted with a BMW 801 TU engine,” is of great interest to me.

CEA 250 indicates that it was fitted with BMW 801, Motornummer 332379 (BMW F/M, München, Werke Allach, Hersteller code = jha). NOTE: CEA 250 actually says, "Q-2 or G-2" (it’s hard to read) but I have always assumed that it was just another of many errors in the CEA reports.

To that point, I have no records of any “Q-2” engines, and, the “G” was geared differently from the “D” and was used on bombers. Also, MNr. 332379 falls within other documented BMW 801 D-2 MNrn. Finally, I have zero references to any ”801 TU” engines at all.

If you have information or documentation showing that it was actually powered by a BMW 801 TU, I would love to update my files.

Steve Sheflin

Re: How did the Rüstsatz system work?
 

From ULTRA:

CX/MSS/R114(C),8
Note seen by source dated 13/2:
Me 109 G-6/R3, W.Nr. 20373, marking 5, taken over on 13/2 from Workshop Guyancourt. Armament 1 MG 151/(C%20) (mech.), 1 FuG 25A, 1 rotary converter 17.

This aircraft went to 4.(F)/123 which seemed to prefer reduced armament on its aircraft. It had many others, not specifically described as /R3, which still had the just the one gun. Of course the correspondence may not always have quoted the complete designation but I think Guyancourt was just converting aircraft to the configuration that each Staffel wanted: NAG 13 109s mostly carried three guns while 4. and 5.(F)/123 mostly had one; NAG 13 and FAG 123 used different cameras.

How did the Rüstsatz system work?
 

Hi Steve

The information that this particular aircraft was fitted with a BMW 801 TU engine came from Philippe Willaume in an e-mail that he sent me some years ago. He mentioned that this aircraft was fitted with a BMW 801 Q but in a later communication stated that it was fitted with a BMW 801 TU. He mentioned PR0 AIR 40/151 as the source of this information. However, given that you have no reference to the BMW 801 TU in your files as well as that the Motornummer appears to be that of a BMW 801 D-2 it seems that there might be a mistake in this. The BMW 801 TU is mentioned in the Fw 190 A-8 handbook as well as in the following memo regarding serial production of the BMW 801 TS for the Fw 190 A-9 so one would assume it must have existed: http://www.wwiiaircraftperformance.o...ft_17-9-44.pdf

Horrido!

Leo

Re: How did the Rüstsatz system work?
 

Triebwerksanlage 801 TU contained the 801 Q-2 engine which was basically a D-2 with thicker armor for the oil cooler. It may have had an increased capacity oil tank/cooler as well. The TU was supposed to be Fw 190 A-8s standard production engine from late summer 44 on.

Re: How did the Rüstsatz system work?
 

It had also a bigger turbo rotor diameter irc

Re: How did the Rüstsatz system work?
 

AFAIR not as the perfomance was the same. The 801S had some supercharger changes.

EDIT: there was no need to remove guns from 109s in close range/tactical recon groups other than to save weight, the G-4/R3 and likely also the G-6/R3 could mount the guns but without ammo box that didn't make sense.