Soviet jet exhaust identification wanted

[Rob de Bie]

Can anyone identify this nozzle / exhaust of a Soviet jet? I looked up Tumansky R-11., R-13, R-25 and Lyulka AL-7 and AL-21, and I don't see a match. But I'm not sure the pictured engines were identified correctly.

 

Rob

 

 

 

 

 

 

[CT7567]

Looks to me like an AL-21 or AL-7 (the former being a derivative of the latter). Compare to the intact display seen at

this link and the exhaust nozzle is a match.

[Rob de Bie]

21 minutes ago, CT7567 said:

Looks to me like an AL-21 or AL-7 (the former being a derivative of the latter). Compare to the intact display seen at

this link and the exhaust nozzle is a match.

 

CT7567, thanks! I think I looked at that page too, and the match is great, but not perfect. On the web page, the exterior shape of each petal is a continuous sort-of circular shape, but the wreck parts have a more complex third-order polynomial. It's probably for the nozzle 'programming' by that control ring that is pulled back to close the nozzle.

 

Rob

 

[CT7567]

Looking closer I see the difference you mean. I also noted that the AL-7/21 "petals" seem to have multiple circular (lightening?) holes on each side, whereas your derelict has single holes in a similar location.  Digging a little more with those characteristics in mind, I believe the Tumansky R-11 is your winner, as seen here

[Rob de Bie]

CT7567, I can see you went through the same process as I did 🙂 Those R-11 nozzle petals do have the correct exterior profile, but they are much wider and flatter. Close but no cigar..

 

Rob

[KRK4m]

22 hours ago, CT7567 said:

Looks to me like an AL-21 or AL-7 (the former being a derivative of the latter). Compare to the intact display seen at

this link and the exhaust nozzle is a match.

While R-11, R-13 and R-25 are subsequent developments of each other (just as R-29 is a development of R-27), AL-21 IS NOT a development of AL-7F. It is a completely new engine, two-shaft, with variable stator vanes, largely based on the GE J79.  The article you linked to is unreliable - the author has little knowledge about jet engines.

But back to the point of this thread - do we know how many petals this afterburner nozzle has? 18 or 24? Because all the Tumansky and Lyulka engines mentioned above are exhibited in the Polish Aviation Museum in Krakow and the afterburner here does not look like this in any of them.

Cheers

Michael

[Rob de Bie]

Michael, thanks for your expert comments, and a big thanks for checking the Tumansky and Lyulka engines in your museum!

 

When I tried to identify the nozzle on the internet, I too got the idea that most engines were not identified correctly, and that this made the investigation nearly hopeless. I was hoping there would be an expert on the forum (say former RAF intel) who could recognise it himself.

 

It's difficult to count the number of nozzle petals. If I use the first photo, and count on the right side, I think I count 10 or 11, making 20 or 22 in total. It looks like a pure convergent nozzle, not a more modern convergent-divergent one. Maybe it's the 'first' nozzle of an ejector nozzle, that effectively has two nozzles (like the early versions of the J79). On the other hand, the green coating looks fresh, suggesting it's from a 'recent' crash, although it must be at least 30 years old. I forgot to mention it was found in East Germany, and the Soviet air force was gone in 1994.

 

Rob

[Rob de Bie]

I studied the petals some more, and made a sketch. One detail that looks pretty unique to me is that the petals slide into each other - in most nozzle designs there's another element to 'fill the gap'. Sorry for the bad explanation, but maybe it helps in the identification.

 

 

Rob

[KRK4m]

@Rob de Bie - IIRC, the Russians had at most a dozen types of afterburner engines. The first way to narrow down the suspects may be the nozzle diameter. In RD-9 it is 65cm, R-11/13/25/27/29, R-15, RD-33, AL-21/31, D-30F are within 90-120cm range, AL-7 is 130cm , RD-7 is 140 cm and NK-25 is over 170 cm. The second thing is the number of petals - Tumansky uses 18, and Lyulka and Soloviev - 24.

I will be at the Museum on Tuesday, January 7, I will look at the R-29 and RD-33 and let you know. Unfortunately, we do not have the AL-31, R-15, RD-7, D-30F and NK-25 in the Krakow museum.

Cheers

Michael

Edited January 2 by KRK4m

[KRK4m]

I was at the Museum today and I have to worry you. This is not one of these engines. The only one in which adjacent petals slide into each other is the RD-9B from the MiG-19. But its petal has lower side walls and without this round hole. In turn, R-11F-2S, R-13 and R-25 have such box-shaped petals with a hole in the side, but they do not slide into each other. R-27, RD-33, AL-7 and AL-21 are a completely different story.

All that remains possible is the small-series R-37F (R-11F-300) from the Mig-21F, which, according to all sources, has a different nozzle than the 11F-2S, and since it is older, it may be based on the petal connection system on the earlier RD-9. Look at the photos :

 

RD-9B    R-11F-2S

 

R-13       R-25

 

R-27       RD-33

 

AL-7F      AL-21

 

Cheers

Michael 

[Rob de Bie]

25 minutes ago, KRK4m said:

I was at the Museum today and I have to worry you. This is not one of these engines. The only one in which adjacent petals slide into each other is the RD-9B from the MiG-19. But its petal has lower side walls and without this round hole. In turn, R-11F-2S, R-13 and R-25 have such box-shaped petals with a hole in the side, but they do not slide into each other. R-27, RD-33, AL-7 and AL-21 are a completely different story.

All that remains possible is the small-series R-37F (R-11F-300) from the Mig-21F, which, according to all sources, has a different nozzle than the 11F-2S, and since it is older, it may be based on the petal connection system on the earlier RD-9. Look at the photos :

 

Michael, another big thanks for all your efforts!

 

I *may* have cracked the puzzle myself, when I bumped into this page:

 

http://авиару.рф/aviamuseum/dvigateli-i-vooruzhenie/aviamotorostroenie/aviamotory-sssr/turboreaktivnye/turboreaktivnyj-aviatsionnyj-dvigatel-rd-7/

 

The first photo on that page shows nozzle petals that slide into each other, without extra different petals to 'fill the gaps' so to speak. You can't see much else, but this is the first nozzle that can't be excluded, I think. So it's likely a Dobrynin VD-7 / RD-7, and that crash was likely of a Tu-22 Blinder. Wow!

 

Rob

[Rob de Bie]

It seems I was too quick with my conclusions.. I based my conclusion on the petals in the lower circle, thinking they were 'one piece', wide petals. But after doing a 'levels' (gamma correction) of the photo, I saw in the upper circle that there are extra petals to 'fill the gaps'. And now that I know that, I sort of see them too at the bottom. Therefore my conclusion was wrong.

 

 

I looked for more Tu-22 nozzle photos, and found the grand total of two. Two different nozzles, but I could not find what versions of the RD-7 / VD-7 they are.

 

The first one (from https://www.airplane-pictures.net/photo/1338587/07-ukraine-air-force-tupolev-tu-22-blinder-all-models/), zoomed in, shows the same nozzle as above I believe, and therefore it's not the same as the wreck photos.

 

 

Here's one from Wikipedia (https://en.m.wikipedia.org/wiki/File:Tupolev_Tu-22PD,_Russia_-_Air_Force_AN1844217.jpg), zoomed in. The petals have an I-shaped stiffener, not a box-shaped. And the exterior contour is totally different. Zero points..

 

 

Back to square one it seems.. Help?

 

Rob

Edited January 8 by Rob de Bie

[KRK4m]

The VD-7/RD-7 is a piece of an engine - a sitting man can easily fit inside the nozzle.

However, I still stand by my version. If the RD-9 in the MiG-19 has petals that slide into each other (without additional connecting elements) and the puzzle is not suitable only for the box being too flat, and on the other hand the R-11F2S from the MiG-21PFM has appropriate petal boxes (square in cross-section), and it does not fit only because of the existence of these additional connectors, the engine from your photos is the missing link between them - it already has a square cross-section of the box, but still has sliding petals. And that missing link can only be the R-37F/R-11F-300.

There is such an engine in the Krakow museum, but it is not exhibited. What is on display is a complete MiG-21F-13, which I personally dragged (with wings installed) on a drawbar behind an Ursus C-385 agricultural tractor from Olesnica to Krakow in September 1989. 300 km and 40 hours behind the wheel non-stop - what memories 🤣. The second tractor in this convoy was dragging an anti-submarine Mi-4ME, whose tyres (not adapted to such distances) fell to shreds along the way.

Unfortunately, the MiG-21F-13 is on outdoor display and access to it is difficult due to the construction of a new 3,000m2 hangar. But I will somehow get to it during my next visit to the Museum - probably not until February. Unless we find photos of such a nozzle somewhere on the Internet.

Cheers

Michael

[JagRigger]

http://data3.primeportal.net/hangar/isaac_gershman/mig-21f-13/images/mig-21f-13_12_of_78.jpg   ?

 

 

[KRK4m]

Well, @JagRigger that's exactly what Rob has been looking for for 10 days. There are 24 petals with a square cross-section of the box, with one-sided stiffening grooves, sliding into each other without an intermediate element. And the hundreds of these aircraft were stationed in the DDR area.

I'm glad I came up with this. Quoting Sir Arthur Ignatius C-D: For God's sake, Holmes, how did you know that?

And I have no other answer to this than: Elementary, my dear Watson...

Cheers

Michael

 

 

 

 

Edited January 8 by KRK4m

[tempestfan]

24 minutes ago, KRK4m said:

.... And the hundreds of these aircraft were stationed in the DDR area.

I'm glad I came up with this. Quoting Sir Arthur Ignatius C-D: For God's sake, Holmes, how did you know that?

And I have no other answer to this than: Elementary, my dear Watson...

Cheers

Michael

 

But then, when it's an engine peculiar to the Mig-21F - when did the NVA-LSK (and Soviet AF) put them out of service? While there is pretty much nothing to date Rob's pics apart from that helmet, they don't look to me like they are 45 to 50 years old. --- If I'm not mistaken, most two-seater 21 variants retained the small intake - does the small intake correlate with this specific engine?

[KRK4m]

I won't cut my head off, @tempestfan but in my opinion the MiG-21F (and F-13) were not the only aircraft powered by the R-11F-300 engine in its original version with these 24 petals that slide into each other. According to Soviet data, the same engine powered the first Indian Fishbeds (called -21FL, externally identical to the PFM, but less powerful) and the first training MiG-21U (those with a narrow fin and Fowler flaps). Another aircraft powered by early R-11Fs was the Yak-28 in its original bomber versions. The production Su-15 certainly did not have this engine - they started with the R-11F2S . Both -21PF/PFS/PFM/M/S and -21US also had R-11F2S with 18 petals connected by an intermediate piece.

However, the diameter of the MiG-21 air intake has nothing to do with the engine type. The amount of air drawn in is the same, and the nose outer diameter is determined by the conical centrebody, which in interceptor versions houses the radar antenna.

Cheers

Michael

[GiampieroSilvestri]

On 31/12/2024 at 21:28, Rob de Bie said:

Michael, thanks for your expert comments, and a big thanks for checking the Tumansky and Lyulka engines in your museum!

 

When I tried to identify the nozzle on the internet, I too got the idea that most engines were not identified correctly, and that this made the investigation nearly hopeless. I was hoping there would be an expert on the forum (say former RAF intel) who could recognise it himself.

 

It's difficult to count the number of nozzle petals. If I use the first photo, and count on the right side, I think I count 10 or 11, making 20 or 22 in total. It looks like a pure convergent nozzle, not a more modern convergent-divergent one. Maybe it's the 'first' nozzle of an ejector nozzle, that effectively has two nozzles (like the early versions of the J79). On the other hand, the green coating looks fresh, suggesting it's from a 'recent' crash, although it must be at least 30 years old. I forgot to mention it was found in East Germany, and the Soviet air force was gone in 1994.

 

Rob

Where was the engine found?

 

Thank you very much

 

Saluti

 

Giampiero

[Rob de Bie]

13 hours ago, JagRigger said:

http://data3.primeportal.net/hangar/isaac_gershman/mig-21f-13/images/mig-21f-13_12_of_78.jpg   ?

 

Bingo!! Many thanks JagRigger!

Rob

[Rob de Bie]

14 hours ago, KRK4m said:

The VD-7/RD-7 is a piece of an engine - a sitting man can easily fit inside the nozzle.

However, I still stand by my version. If the RD-9 in the MiG-19 has petals that slide into each other (without additional connecting elements) and the puzzle is not suitable only for the box being too flat, and on the other hand the R-11F2S from the MiG-21PFM has appropriate petal boxes (square in cross-section), and it does not fit only because of the existence of these additional connectors, the engine from your photos is the missing link between them - it already has a square cross-section of the box, but still has sliding petals. And that missing link can only be the R-37F/R-11F-300.

There is such an engine in the Krakow museum, but it is not exhibited. What is on display is a complete MiG-21F-13, which I personally dragged (with wings installed) on a drawbar behind an Ursus C-385 agricultural tractor from Olesnica to Krakow in September 1989. 300 km and 40 hours behind the wheel non-stop - what memories 🤣. The second tractor in this convoy was dragging an anti-submarine Mi-4ME, whose tyres (not adapted to such distances) fell to shreds along the way.

Unfortunately, the MiG-21F-13 is on outdoor display and access to it is difficult due to the construction of a new 3,000m2 hangar. But I will somehow get to it during my next visit to the Museum - probably not until February. Unless we find photos of such a nozzle somewhere on the Internet.

 

Michael, you predicted the outcome 100% correct!!

 

40 hours non-stop on a tractor towing a MiG - my hat is off for your job dedication..

 

Rob

[Rob de Bie]

4 hours ago, KRK4m said:

I won't cut my head off, @tempestfan but in my opinion the MiG-21F (and F-13) were not the only aircraft powered by the R-11F-300 engine in its original version with these 24 petals that slide into each other. According to Soviet data, the same engine powered the first Indian Fishbeds (called -21FL, externally identical to the PFM, but less powerful) and the first training MiG-21U (those with a narrow fin and Fowler flaps). Another aircraft powered by early R-11Fs was the Yak-28 in its original bomber versions. The production Su-15 certainly did not have this engine - they started with the R-11F2S . Both -21PF/PFS/PFM/M/S and -21US also had R-11F2S with 18 petals connected by an intermediate piece.

However, the diameter of the MiG-21 air intake has nothing to do with the engine type. The amount of air drawn in is the same, and the nose outer diameter is determined by the conical centrebody, which in interceptor versions houses the radar antenna.

 

What still confuses me it that roughly half of preserved MiG-21Fs have the nozzle like the wreck pieces, and the other half has a different nozzle. I made an overview of all photos I could find:

 

'Boxy petals' nozzle (like the wreck parts)

 

   MiG-21F-13 '007' Israeli Air Force Museum
   http://data3.primeportal.net/hangar/isaac_gershman/mig-21f-13/images/mig-21f-13_12_of_78.jpg
   from http://www.primeportal.net/hangar/isaac_gershman/mig-21f-13/

 

   MiG-21F-13 '63' NASM Udvar-Hazy 2015
   https://447bg.org/museum/wp-content/gallery/mig-21-fishbed-udvar-hazy-2015-10-23/Mig-21-Fishbed-Udvar-Hazy-2015-10-23-2887.jpg
   from https://447bg.org/air-modern/modern-russian/mig21-fishbed/

 

   MiG-21F-13 'MG-78' at Karhulan ilmailukerho Aviation museum
   https://upload.wikimedia.org/wikipedia/commons/1/1d/MiG-21F-13_(MG-78)_Karhulan_ilmailukerhon_lentomuseo_09.JPG
   from https://commons.wikimedia.org/wiki/File:MiG-21F-13_(MG-78)_Karhulan_ilmailukerhon_lentomuseo_09.JPG

 

'Flat petals with filler plates' nozzle

 

   MiG-21F '1112' Palm Springs Air Museum 2018
   https://447bg.org/museum/wp-content/gallery/mig-21-palm-springs-2018-04-12/MiG-21-Palm-Springs-2018-04-12-8199.jpg
   from https://447bg.org/air-modern/modern-russian/mig21-fishbed/

 

   MiG-21 F-13 '0514' Aviation Museum Kunovice 2021
   https://youtu.be/uMXFAjZRXzg&t=206

 

   cutaway engine
   http://www.leteckemotory.cz/motory/r-11/r-11f-300_vystup.jpg
   from http://www.leteckemotory.cz/motory/r-11/

 

One explanation could be that we're looking at the R11F-300 and the R11F2-300, but I cannot find anything solid about the differences. This website https://www.mig-21.de/english/technicaldataengines.htm reports:

R11F-300 (37F) in  MiG-21F, F-13, U
R11F2-300 (37F2) in MiG-21F-13 (refitted), PF, FL

 

Does anyone know which is which?

 

Rob

Edited January 9 by Rob de Bie

[Rob de Bie]

2 hours ago, GiampieroSilvestri said:

Where was the engine found?

 

Giampiero, it was found at Templin / Gross Dolln, see this Youtube video: https://www.youtube.com/watch?v=aZaHqPtVw3s&ab_channel=MarcoJust(eigeneDokus)

 

Rob

[Duncan B]

This has been a fascinating thread to follow. I have nothing to add to the discussion other than to say that the wreckage is remarkably clean, no corrosion, no moss or dirt on it, not even any cobwebs. Amazing, it looks like it could have been dumped there last week! (I'm not suggesting it was, just that it is remarkably clean for its age compared with wrecks that I am familiar with).

 

Duncan B

[KRK4m]

6 hours ago, Rob de Bie said:

 

What still confuses me it that roughly half of preserved MiG-21Fs have the nozzle like the wreck pieces, and the other half has a different nozzle. I made an overview of all photos I could find:

 

'Boxy 24 petals' nozzle (like the wreck parts)

•  MiG-21F-13 '007' Israeli Air Force Museum
•  MiG-21F-13 '63' NASM Udvar-Hazy 2015
•  MiG-21F-13 'MG-78' at Karhulan ilmailukerho Aviation museum

'Flat 18 petals with filler plates' nozzle

•   MiG-21F '1112' Palm Springs Air Museum 2018
•   MiG-21 F-13 '0514' Aviation Museum Kunovice 2021
•   cutaway engine from http://www.leteckemotory.cz/motory/r-11/

One explanation could be that we're looking at the R11F-300 and the R11F2-300, but I cannot find anything solid about the differences. This website https://www.mig-21.de/english/technicaldataengines.htm reports:

• R11F-300 (37F) in  MiG-21F, F-13, U
• R11F2-300 (37F2) in MiG-21F-13 (refitted), PF, FL

Does anyone know which is which?

Rob

 

Again, I'm not 100% sure, but I'll check in February when I'm back in the Krakow museum. In addition to the 200 engines on display, there is also an outdoor display of a dozen MiG-21s in all versions formerly used in Poland (F13, PF, PFM, PFMA, R, M, MF, U4, U6, US, UM and bis). I will compare the F13, PF, U4 and U6 nozzles (all later ones have blown flaps, so they must have an R-11F2S, R-13 or R-25 engine) with the individual airframe books and we will be clear. As for today - using deduction - I suspect that you answered yourself correctly with the bolded part of your statement above.

Cheers

Michael

 

[GiampieroSilvestri]

11 hours ago, Rob de Bie said:

 

Giampiero, it was found at Templin / Gross Dolln, see this Youtube video: https://www.youtube.com/watch?v=aZaHqPtVw3s&ab_channel=MarcoJust(eigeneDokus)

 

Rob

Maybe this is of some interest.

 

Saluti

 

Giampiero

 

"Die erste Belegung erfolgte vom April bis September 1955 durch Il-28-Frontbomber. Von 1956 bis 1970 waren in Templin Jagdfliegerkräfte des 787. Jagdfliegerregiments mit MiG-17/19/21 und Jak-25, von 1970 bis 1994 Jagdbomberfliegerkräfte des 20. Garde-Jagdbombenfliegerregiments (MiG-15/17, Su-7/17 und Schulflugzeuge L-29) und ab 1969 auch Hubschrauberfliegerkräfte (Mi-2/8/9/24) der GSSD dauerhaft stationiert. Für die sowjetischen Jagdbomber soll in Templin ein mit Atomwaffen bestücktes „Sonderlager“ zum Einsatz gegen Ziele in Westdeutschland existiert haben.[1] Andere Lager waren auf den Flugplätzen Lärz, Brand, Finsterwalde und Großenhain angelegt.[2] In unregelmäßigen Abständen waren in Templin kurzzeitig auch strategische Bomber vom Typ Tu-16, Tu-22 und Tu-22M sowie Transporter An-12 und An-22 stationiert. Von 1985 bis 1986 lag in Templin das 787. Jagdfliegerregiment, ausgerüstet mit MiG-23 und MiG-25. Ab 1971 diente der Flugplatz als Zubringerflughafen zum Austausch der sowjetischen Armeeangehörigen in der DDR. Er wurde deshalb turnusmäßig im Mai und November des Jahres von Passagierflugzeugen der Aeroflot (Il-18/62/76, Tu-104/114/154) angeflogen. Die LSK der NVA erhielten über den Flugplatz ihre MiG-21-Jagdflugzeuge zugeteilt, die vom Herstellerwerk hierher überführt wurden."