Rüstsätze and Umrüst-Bausätze management

[greybeard]

I wonder how these modifications were field-managed. I mean, was Rüstsätze applied according to mission? Was it possible? Or conversion time was too much, so, when applied, it remained for a long time (until a major requirement forced to remove/change it)? If this latter was the rule, was it practiced to "pick the right plane", so to speak? I mean, could a pilot pick most suited aircraft arranged for the given mission? Same question for Umrüst-Bausätze, since these latter couldn't be applied at all on field.

Thanks for any help,
GB

 

[greybeard]

BUMP!

(I wonder if my question didn't get answer so far because it's too hard or too silly)

 

[Shortround6]

You also have a training problem. If one kit turns the plane into a fighter bomber and another kit turns it into a bomber destroyer, those are different roles that require different tactics and training in order to be successful. Trying to switch a squadron or group from one role to another on different days of the same week probably isn't a good idea. Most squadrons or groups probably didn't have a variety of these "kits"
in stock either. The "kits" may have been held at a higher echelon and fitted to replacement aircraft ( or sent with them) before they were issued to the Squadrons or groups.

Most squadrons or groups did not have a surplus of aircraft for pilots to pick from and in fact most squadrons and groups specialized in one mission, such as a Jabo (fighter bomber) squadron or group or a interceptor squadron or group.

 

[stona]

I saw this thread but then it disappeared...at least for me.

Firstly the Rustsatze kits and Umrust-Bausatze modifications which resulted in the R or U suffix in the sub type designation were Messerschmitt nomenclature and don't apply to other manufacturers.

There is still debate about the difference between a Rustzustand and a Rustsatze. Let's not go there. I will accept that an R number denotes an "add on" kit,a Rustsatze.

Most Rustsatze kits could be fitted post production. This is only because from the F series onwards all the internal plumbing and wiring for auxiiary fuel tanks or bomb racks was fitted as standard. Wiring for underwing cannon gondolas was added from the first of the G series production.
I don't believe they were mission specific in the sense that they were taken off and refitted regularly. I know of instances where captured Luftwaffe pilots,during interogation,complained about having "bomb slips" as the British called an ETC rack,fitted when they were engaged in "Freijagd" fighter operations.
Likewise flying Defence of the Reich missions,fighters only carried a drop tank on the first mission of the day. There was no way the rack could be removed for subsequent missions as an entire Gruppe was supposed to refuel,rearm and be ready to go again in 25 minutes.
Removing outboard cannon might have serious consequences for the CoG and stability of the aircraft. I would be surprised if this was something undertaken lightly. Someone else may have better information on that.
As far as choosing an aircraft to fit a mission,most units were equipped with similar aircraft. Given the woeful serviceability rates prevalent in most Luftwaffe units,pilots would take whatever would fly.

Umrust-Bausatze are major modifications undertaken on the production line. The U number will denote things like the boost system fitted,armament variations,cockpit pressurisation and other major installations which would be impossible to remove or alter in the field.
There are instances when the U designation of an aircraft should have been changed but only as a result of a major rebuild and certainly not at unit or even Luftwaffe level. Such an aircraft would have passed into the manufacturer's or a sub contractor's repair and salvage system and technically left Luftwaffe control.

Cheers

Steve

 

[Denniss]

Rüstsätze were usually applied and removed upon mission needs.
Applying a Rüstsatz did never change an aircraft designation (true Rüstsatz, not the conversion kits improperly named Rüstsatz used on Fw 190).
Both Rüststand/Rüstzustand and Umrüst-Bausatz were usually applied in the factory but some could also be done in larger repair/modification facilities.
Only the Rüststand/Rüstzustand and Umrüst-Bausätze changed an aircraft designation.

 

[stona]

Rüstsätze were usually applied and removed upon mission needs.

Really? A typical Rustsatze would be a rack,for a bomb or auxiliary fuel tank. I have seen no evidence that these were removed depending on the mission and plenty of evidence to suggest that they were not. The idea that ground crews were removing and re attaching such devices on a mission by mission basis is not correct. They certainly could be fairly easily removed even at Staffel level,but that didn't happen on a mission by mission basis.

You say that a Rustsatze does not change the designation of the aircraft and here we touch on an area I did earlier avoid.

How would you characterise a Bf 109 G-6/U4/R1 ? A G-6 with a MK 108 cannon and an ETC 500 bomb rack?

As always there seems to be more than one way of interpreting this stuff

Steve

 

[davebender]

The idea that ground crews were removing and re attaching such devices on a mission by mission basis is not correct. They certainly could be fairly easily removed even at Staffel level,but that didn't happen on a mission by mission basis.

I agree.

It was common for Me-109, Fw-190 and Ju-87 units to fly several sorties per day during periods of heavy combat. Changing Rustsatze would probably cut sortie rate to one mission per day. That's not acceptable when Heer infantry need air support by yesterday or else they will be over run.

 

[greybeard]

Thank you very much to all for replies!

Interesting Shortround's clarification about specialized units. Enlightening practical description by Steve. Interesting addition by Davebender, while Denniss opens a possibility about more frequent changeovers.

So far, if I correctly understood, the most realistic "picture" was Rüstsätze applied mostly according to unit's main role (likely assigned at higher level) seldom allowing picking of mission-suited aircraft as well as field modification. Umrüst-Bausatz, a fortiori, was planned at higher level and assigned according unit's role, with even narrower possibility to pick the most suitable plane for a mission.

S!
GB

 

[Denniss]

How would you characterise a Bf 109 G-6/U4/R1 ? A G-6 with a MK 108 cannon and an ETC 500 bomb rack?

impossible combination, R1 was an experimental aircraft with two underwing droptanks, a 500kg bomb and an additional (droppable) wheel to get enough ground clearance for the big bomb. This was only tested with a G-2 but never made it into production although they may had planned it (job was done by Fw 190G, more range and no need for this additional wheel).

Rüstsätze were designed for quick changes - you could keep the droptank and add wing guns and for a later ground strafing mission keep the wing guns and mount 4x50kg (or bomblets) bombs instead of the DT.

You should see the /U or real /R numbers stamped onto the aircraft's dataplate.

 

[stona]

Rüstsätze were designed for quick changes - you could keep the droptank and add wing guns and for a later ground strafing mission keep the wing guns and mount 4x50kg (or bomblets) bombs instead of the DT.

You should see the /U or real /R numbers stamped onto the aircraft's dataplate.

You show me any evidence that cannon pods were fitted and removed on a mission by mission basis. They could be installed and removed fairly quickly but it simply wasn't done on a mission or daily/weekly basis. Nor were ETC racks (underbelly or wing) removed and attached to suit the mission.

Your second point is touching on the issue I raised regarding R numbers in my first post. U4 for the G-6 was a Mk 108 cannon. Rustsatze 1 was an ETC rack. I understand that you are saying that the Rustsatze number would not appear on the data plate. With that I agree.

Cheers

Steve

 

[Denniss]

You talked about a G-6/U4/R1 - that would be a G-6/U4 with Rüstzustand 1 - A G-6/U4 with Rüstsatz I is a G-6/U4 with R I and nothing else.
Mtt was obviously aware of the R number confusion, many Rüstsatz manuals used therefore roman numerals.

BTW if they don't need the gunpods for a bombing mission they would remove them - I don't think they used planehopping tactics (use reserve plane with different configuration). Did the Bf 109 have underwing bombracks?

 

[Snautzer01]

Did the Bf 109 have underwing bombracks?

Not the german ones. Swiss ones could be fitted

Rüstsätze is more then just hanging a schloss and a bomb under an airframe. Think of all the wiring,switches etc. And it is for the military planners how and with what loadout the plane is sent into battle. It is not an option the pilots or gruppen could choose on their own.

 

[stona]

Did the Bf 109 have underwing bombracks?

No

I had a picture in my mind of an Fw 190 with an AB 500 slung underneath and unused racks on the wings. I didn't mean to confuse.

Cheers

Steve