Ju 87 D-5 Gunsight References

[LukeFF]

Hey all, I'm forwarding this message from VikS, regarding the gunsight in the Ju 87 D-5:

 

Quote

Maybe someone from the community can answer the question or have info about Stuvi on Ju-87?

Some sources state that there was no BZA (computer which calculated input for Stuvi sight moving mark) installed on Ju-87 with Stuvi, but in that case - whats the point of having it? as in that case - with "hand mode" pilot will move it manually - it is just the same as to have a swivel plate or tilted reflector glass PS: for the moment there are no photos of controls (QFF and Vw) installed in Ju-87 cockpit as well as - only external photos of Stuvi installation are available as for the moment the plan is to make it same as on 410 - controls will be in gunner's cockpit.

 

[Charon]

23 hours ago, LukeFF said:

for the moment there are no photos of controls (QFF and Vw) installed in Ju-87 cockpit as well as - only external photos of Stuvi installation are available as for the moment the plan is to make it same as on 410 - controls will be in gunner's cockpit.

 

QFE and Vw are inputs to the BZA, so if that's not equipped it doesn't make sense to provide those controls.

 

My very strong suspicion is that the Stuvi would simply be adjusted by the pilot using the wheel on its side. In Deutsche Avionik's video we can see that wheel move as the BZA commands, but the wheel is also knurled, so obviously intended to be adjusted by hand too. The wheel is likely linked mechanically to the scale. That's enough for the pilot to set any offset they want. (Edit: Bussard's link has a full schematic and confirms it can be set directly on the Stuvi)

 

23 hours ago, LukeFF said:

- whats the point of having it? as in that case - with "hand mode" pilot will move it manually - it is just the same as to have a swivel plate or tilted reflector glass

I agree, if used in this way it is, for the purposes of bombing, the same as a swivel plate. L.DV. 20/2 [link] Tables 1 and 2 describe the offset to use in various conditions and Stuka pilots would have been familiar with those, so I don't think it would have been a problem for them to bomb with it in that way.

 

However, the Stuvi has the advantage that the gun aiming mark is separate from the bomb-aiming mark. With the SP-2A swivel plate the pilot must dial in one setting for bombing, then revert to the 0 degree setting to put the crosshair back where it belongs for strafing. That's not necessary with the Stuvi, the pilot can bomb, then strafe, then bomb again without needing to make any adjustment. And with the D-5 getting upgraded armament for that exact purpose it makes sense that they would want a reflector sight that supports both.

Edited February 22 by Charon

[Charon]

8 minutes ago, Charon said:

L.DV. 20/2

 

And this PDF describes on page 27 the offsets to be used in low-level attacks. You've probably already seen it, but I include it for completeness, and for anyone else who is trying to track it down.

[ACG_Bussard]

From the article linked below about the BZA, formerly available via <Deutsche Luftwaffe>, the following can be inferred from my point of view:

 

“A. Intended use
The BZA 1 B bomb aiming system is an aiming device for gliding or dive attacks. Depending on the type of aircraft (cockpit shape and visibility), the BZA 1 B is used in conjunction with a reflex sight (Stuvi 5 B or Stuvi 5 E) or a PV 1 B pilot sight.”

 

“Stuvi 5 B function

The light bulb of the Stuvi 5 B is already illuminated when the automatic switches (or the automatic switch) for the BZA 1 B in the main control panel are switched on. In this case, the weft agreement and longitudinal thread are visible even if the Stuvi is not yet switched on, i.e. the Stuvi toggle switch (19) is positioned so that the label “Stuvi is OFF” can be read. The Stuvi toggle switch and changeover lever (16) are coupled together and lock each other. Only when the toggle switch is set to “Stuvi is OFF” can the changeover lever be moved upwards and the sight switched to sight angle input by hand. On the other hand, the toggle switch cannot be set to “Stuvi is ON” as long as the changeover lever is set to manual input. The respective lever position can be recognized from the front by the mark (17), which points either to “Hand” or to “BZA”.

Setting a fixed sighting angle by hand is necessary if important parts of the BZA 1 B have failed (e.g. due to fire) and the sighting angle is no longer transmitted from the fore-end computer to the sight.

...”

 

“B. General notes (errors)

In addition to the operating instructions listed under A., the following instructions must also be observed:
...

 

11) If the BZA fails, it is possible to throw from low altitudes according to fixed sight angle values. To do this, switch the sighting lever to “Hand” and, in the case of the Stuvi, also switch the sighting switch to “Stuvi is OFF” and set the sighting angle with the hand wheel. During the attack, the target must be stopped while gliding around the wind compensation angle, below the center of the firing circle if there is a headwind and above the center of the firing circle if there is a tailwind. Shortly before reaching the intended release altitude, the aircraft is ogen and the bomb is released as soon as the target and the throwing agreement are aligned. The chances of hitting the target with this method of throwing are poor, as estimating the inclination of the trajectory requires a great deal of practice, and errors in the inclination of the trajectory produce considerable errors in the throwing range, particularly in the surface gliding attack.

...”

 

I have translated the quotes with DeepL.com (free version)

 

Here´s the link to source:

https://web.archive.org/web/20190129182218/http:/www.deutscheluftwaffe.com/archiv/Dokumente/ABC/r/Reflexvisiere/BZA_1/BZA 1.html

Edited February 22 by ACG_Bussard

[Juri_JS]

From reading the German instructions on the Stuvi, it sounds like the dive-bombing methode of rolling over to the side before starting the dive, that's currently used by the AI when flying the Ju-87 D-3 in the game, couldn't be used when the Stuvi was installed. Can anyone confirm this? 

[Charon]

30 minutes ago, Juri_JS said:

From reading the German instructions on the Stuvi, it sounds like the dive-bombing methode of rolling over to the side before starting the dive, that's currently used by the AI when flying the Ju-87 D-3 in the game, couldn't be used when the Stuvi was installed. Can anyone confirm this? 

 

Not when the BZA is installed, but the Stuka doesn't seem to have been equipped with one so it's a moot point. The Stuvi alone should be fine. Have a look at the schematics, it's little more complicated than an ordinary Revi; it has no gyros to topple or anything like that.

[ACG_Bussard]

 

50 minutes ago, Juri_JS said:

From reading the German instructions on the Stuvi, it sounds like the dive-bombing methode of rolling over to the side before starting the dive, that's currently used by the AI when flying the Ju-87 D-3 in the game, couldn't be used when the Stuvi was installed. Can anyone confirm this? 

 

Tilting over the longitudinal axis was probably the preferred and appropriate method for the transition to the gliding attack with the BZA:

 

 

 

 

I´m sorry that I don´t have any documents regarding the installation and usage of the Stuvi in the Ju 87 D-5 in my hands.

 

[ACG_Bussard]

21 hours ago, LukeFF said:

Hey all, I'm forwarding this message from VikS, regarding the gunsight in the Ju 87 D-5:

 

 

 

Why should the dials for ZH/QFF, Ve and Vw placed to the rear gunner? From my point of view there would be enough space to the right of the pilot's seat along, as the bomb panel <Auslöseschrittschaltwerk> has moved to the front below between the legs according to this photo of a Ju 87 D-5 cockpit.

 

That would be much more practical than switching to the rear gunner's position in game, when readjustments are required. Just an idea.  

[Charon]

1 hour ago, ACG_Bussard said:

Why should the dials for ZH/QFF, Ve and Vw placed to the rear gunner? From my point of view there would be enough space to the right of the pilot's seat along, as the bomb panel <Auslöseschrittschaltwerk> has moved to the front below between the legs according to this photo of a Ju 87 D-5 cockpit.

Do you have evidence the Stuka was ever equipped with the BZA, though? These dials are meaningless without it.

[ACG_Bussard]

1 hour ago, Charon said:

Do you have evidence the Stuka was ever equipped with the BZA, though? These dials are meaningless without it.

 

VikS from the developers intends this, see the quote from LukeFF in the first post. There's nothing more to say from my point of view, as my sources support this. 😉

[Charon]

1 hour ago, ACG_Bussard said:

There's nothing more to say from my point of view, as my sources support this. 😉

 

How do you figure that? Your second post show these controls routed into the BZA. Unless you're arguing that the Stuka was equipped with a BZA (and I don't think you're arguing that, I think we all agree that it wasn't) it only confuses the matter to argue where nonexistent controls should be placed.

Edited February 22 by Charon

[ACG_Bussard]

Do you see what I see?

 

Transport box with content:

 

Sturzvisier Stuvi 5B:
https://www.deutscheluftwaffe.de/fl-52870-sturzvisier-stuvi-5b-1944

 

Relaiskasten IRK 1 (no extra picture and link, only be seen in the Transport box)

 

Windgeschwindigkeitsgeber Vw-Geber IWG 1:    
https://www.deutscheluftwaffe.de/fl-52832-windgeschwindigkeitsgeber-iwg-1-1944

 

Eigengeschwindigkeitsgeber Ve-Geber IEG 1:
https://www.deutscheluftwaffe.de/__trashed-2

 

Höhenkorrekturgeber ZH-/ QFF-Geber IHKG 1:    
https://www.deutscheluftwaffe.de/fl-52830-hoehenkorrekturgeber-ihkg-1-1944-2

 

Gleichstrom-Drehstrom-Umformer GDU 30:
https://www.deutscheluftwaffe.de/fl-22420-gleichstrom-drehstrom-umformer-gdu-30-1943-2

 

Schaltkasten SVKe (no link):

 

P.S. Hope that I could help you a bit. If you have any complaints, please provide a link or name your verifiable sources for the benefit of those reading along. Thank you.

Edited February 24 by ACG_Bussard

[=FB=VikS]

btw - Me-410 had BZA-3 installed - and had only Vw and QFF control available to control (with Ve auto input) and controls are placed in gunners cockpit (thats where idea came from)

so the main question - does Ju-87 had these controls at all? and if no any info about its installation  and no info about controls - just to put it the same way as on 410.
"Nobody seen it - but its there" (c)

[ACG_Bussard]

3 hours ago, =FB=VikS said:

btw - Me-410 had BZA-3 installed - and had only Vw and QFF control available to control (with Ve auto input) and controls are placed in gunners cockpit (thats where idea came from)

so the main question - does Ju-87 had these controls at all? and if no any info about its installation  and no info about controls - just to put it the same way as on 410.
"Nobody seen it - but its there" (c)

Just yesterday I gave LukeFF a literature reference regarding the Ju 87 D-5 that should shed some light on this matter. I hope he forwards it to you soon. 

 

Anecdotally, I would like to add that the flight engineer and test pilot in Rechlin and Berlin-Gatow, Mrs. Melitta Schenk Gräfin von Stauffenberg, was proposed for the award of the Iron Cross First Class in January 1944. Among other things, this was because of point 17 for “"Trefferbilder mit JU 87 und BZA 4". 

 

Source: 
http://www.hpmelle.de/stauffenberg/melitta.html

Edited February 26 by ACG_Bussard