How did the Rüstsatz system work?

[Broncazonk]

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

[Alfred.MONZAT]

Hello,

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

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.

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

[Broncazonk]

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

[Graham Boak]

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?

[Alfred.MONZAT]

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.

[harrison987]

Originally Posted by Broncazonk

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?

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.

[Broncazonk]

Originally Posted by Graham Boak

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?

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

[harrison987]

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.

[Denniss]

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.

[Broncazonk]

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

Originally Posted by Leo Etgen

Hi guys,

Regarding the removal of the outer cannon it is true that many aces flew these without such as Bär, Priller and Weiss to mention a few but on the other hand Unteroffizier Ernst Schröder (7 victories) of 5./JG 300 is quoted that he was refused permission to remove the outer cannon of his famous Fw 190 A-8 "Red 19" (W.Nr. 172 733) in Focke Wulf Jagdflugzeug by Rodeike.

Horrido!

Leo