MIG-29 Question?

[Fly26]

Today at RIAT during the Typhoon/Spitfire Battle of Britain display (which was outstanding in itself) the Polish Mig 29 was waiting at the holding point prior to its display slot, when roughly every 5mins or so it did a brief engine run up emitting a cracking amount of black exhaust smoke. I'm just curious, to what causes so much black smoke, and is this a normal pre-takeoff procedure when holding? Incidentally the answer was explained over the speaker during the display but it was perfectly timed with a climb on re-heat, so I don't think much was heard by anyone north of Swindon! Funnily, it was the only aircraft I could smell as well, which I thought was a brilliant two fingers to the emissions driven world we are constantly reminded about in modern life! Anyhow, up there with the best displays of the day.....thanks to all the crews, both air and ground, excellent day.

Thanks in advance for the answer...F26

[Bigbux]

Funnily, it was the only aircraft I could smell as well, which I thought was a brilliant two fingers to the emissions driven world we are constantly reminded about in modern life!

Yeah!...screw the air we breathe, it's not like we couldn't last very long without it.

[Bevo]

It is because of the design of the RD-33 engine combustion chamber on the earlier engines. The Klimow RD-33 was the first Russian turbofan jet engine in mass production. It has a one stage injector which is not as efficient as many western designs. A new version of that engine (RD-33MK) doesn’t smoke as much. Poland’s MiG-29s do not have upgraded engines because of political reasons and cost.

Sometime around 1998, Petr Izotov, V.Ya.Klimov plant chief designer was quoted as saying: “Smoke is absolutely subjective. It would be a problem if it would affect plane’s flight performance or engine characteristics. But it doesn’t!” Obviously the operational implications of being seen at much longer ranges was not mentioned.
http://i.wp.pl/a/f/jpeg/29837/mig_29_alarm_zoom_2.jpeg

[Courtney Mil]

Bevo, good answer and great pic. Thanks. :ok:

[rh200]

Reminds me of an old Mack truck with the puff limiter disconnected:p

[dat581]

Almost as much smoke as a J79 Phantom.

[ORAC]

Just an itsy-bitsy bit of smoke.

Xo8AS7l81JU

Almost as much as a B-52

LU6DoQOd6z0

[Fly26]

Thanks Bevo! I appreciate the answer, I thought there might be a more in depth reason for it. Brilliant picture, that's pretty much what we all saw. Sorry Bigbux I'm sure I heard between the noise they will be operational until 2030 :ok:

[DirtyProp]

It is because of the design of the RD-33 engine combustion chamber on the earlier engines. The Klimow RD-33 was the first Russian turbofan jet engine in mass production. It has a one stage injector which is not as efficient as many western designs. A new version of that engine (RD-33MK) doesn’t smoke as much. Poland’s MiG-29s do not have upgraded engines because of political reasons and cost.

Sometime around 1998, Petr Izotov, V.Ya.Klimov plant chief designer was quoted as saying: “Smoke is absolutely subjective. It would be a problem if it would affect plane’s flight performance or engine characteristics. But it doesn’t!” Obviously the operational implications of being seen at much longer ranges was not mentioned.
http://i.wp.pl/a/f/jpeg/29837/mig_29_alarm_zoom_2.jpeg
Holy crap!
Maybe one of its "secret tactics" is to smoke the enemy to death...:E

[HookEcho]

I think they got a good deal on the F4's J79s :)

[Argonautical]

I always hypothetically thought it would have been a good candidate for being re-engined with a pair of Eurojet EJ200 engines.

[GlobalNav]

Not likely, but they may have "copied" a feature without knowing its purpose. A few other items from the F4 made its way into Soviet aircraft.

[glad rag]

It is because of the design of the RD-33 engine combustion chamber on the earlier engines. The Klimow RD-33 was the first Russian turbofan jet engine in mass production. It has a one stage injector which is not as efficient as many western designs. A new version of that engine (RD-33MK) doesn’t smoke as much. Poland’s MiG-29s do not have upgraded engines because of political reasons and cost.

Sometime around 1998, Petr Izotov, V.Ya.Klimov plant chief designer was quoted as saying: “Smoke is absolutely subjective. It would be a problem if it would affect plane’s flight performance or engine characteristics. But it doesn’t!” Obviously the operational implications of being seen at much longer ranges was not mentioned.
http://i.wp.pl/a/f/jpeg/29837/mig_29_alarm_zoom_2.jpeg

Ignoring the smoke, looking at that picture, that's one hell of an aerodynamic beastie, Bit like the Viper when you get up REAL close and follow the lines....

Both had brilliant designers/teams IMO.

[O-P]

Bevo is correct about the combustor design. But, in addition, combustion temp is also an important factor. Colder=more smoke.

[Danny42C]

Can't believe this hoary old one hasn't popped up yet:

(Voice from the cloud......):

"Never mind, sonny - when you grow up you'll be able to smoke, too !"

D.

[27mm]

Well, the J79 engined F4s were smoky, but then so were our Spey engined F4s; min burner killed the smoke.

[Courtney Mil]

The Speys had nothing on the J-79s, 27mm. Looking along a smoke trail, it was pretty obvious on the Ks and Ms, but nowhere near as bad.

Holy smoke!

http://farm8.staticflickr.com/7299/9170632870_ccd215bf71_b.jpg

Image credit: Phantom Pharewell, Wittmund, June 29th 2013 by Gerben Wessels, on Flickr

[Courtney Mil]

^^^Oops, sorry. Huge photo. I'll leave it for a bit and then take it down if it's annoying.

[iansmith]

Was the laying of smoke screens included in their training?

[Heathrow Harry]

plan was to choke the WP forces to death..............

[Rhino power]

How come the GAF never incorporated the smokeless mod for their J79s full time? I understand they had it as a 'war only' option, did the smokeless mod increase wear and tear on the engines due to the higher combustion temperatures that much that it was not worth it during peacetime?
As an aside, look at almost any footage of current JASDF F-4's and you'd think they didn't have J79s, they're as clean a whistle!

-RP

[Fly26]

For those in the know, was the smoke the first thing you usually spotted when practising air to air? I guess when conducting NATO patrols or any other operations the Mig 29s were a bit easier to spot, or am I wrong?

Thanks F26

[Turbine D]

A couple of things regarding combustors on F-4 Phantoms (J79 engines) and Mig-29 (RD-33 engines):
The J79 engine used a 10 cannular combustor system.
The RD-33 used an annular combustor system.

The early GE J79 engines used a longer combustor "can" and dual orifice pressure atomizing fuel nozzles, the nozzles had a single fuel inlet and an external fuel flow dividing valve. Starting with the GE J79-17C engine, the fuel nozzle tip was changed to provide air blast atomization to improve fuel/air mixing. The new fuel nozzle was made longer to compensate for a shorter "can" length that was also developed. The new fuel nozzle was quite complex as it involved the addition of eight radial low pressure secondary fuel distributers. This change was known as "Low Smoke - Long Life Combustor" and it was an improvement for sure.

I was with a team of engineers that visited all the important Soviet jet engine plants just as the Soviet Union was dissolving. We were looking for advanced Russian technology knowhow, something better than what we were doing at the time. I had an opportunity during this visit to see a RD33 engine with all the parts laid out on tables for our review. The engine was a basic copy of an F404 engine including the HP turbine blade cooling methodology. However, there was a significant difference and that was the manufacturing ability to produce the wanted component designs. This is where the early "smokey" RD33 engines came up short. There wasn't the manufacturing capability to produce the sophisticated type of parts (fuel nozzles) that was developed and being used in the Western world. We could see that throughout the RD33 engine, they had the right engineering but not the manufacturing capability. So the Chief Designer is covering for the manufacturing shortcomings.;)

[OFBSLF]

^^^Oops, sorry. Huge photo. I'll leave it for a bit and then take it down if it's annoying.

Large photos of a smokey F4 low pass is definitely NOT annoying. :D

[27mm]

Did the IAF re-engine their F4s with GE donks?

[Willard Whyte]

^^^Oops, sorry. Huge photo. I'll leave it for a bit and then take it down if it's annoying.

Nah, people should just get better computers. Fits perfik here.

[DirtyProp]

The early GE J79 engines used a longer combustor "can" and dual orifice pressure atomizing fuel nozzles, the nozzles had a single fuel inlet and an external fuel flow dividing valve. Starting with the GE J79-17C engine, the fuel nozzle tip was changed to provide air blast atomization to improve fuel/air mixing. The new fuel nozzle was made longer to compensate for a shorter "can" length that was also developed. The new fuel nozzle was quite complex as it involved the addition of eight radial low pressure secondary fuel distributers. This change was known as "Low Smoke - Long Life Combustor" and it was an improvement for sure.
Interesting, thank you.
I was able to find a pdf about it, are there any pics or cutaways somewhere?
The ones on the report are pretty much useless (at least for me). Here's the file:
www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA095057

[Rhino power]

Did the IAF re-engine their F4s with GE donks?

No, they already had GE engines. You're probably thinking of the Israeli 'Super Phantom' proposal. One aircraft flew with a pair of P&W PW1120s, which were developed from the P&W F100. Although test flights showed significant improvements in performance, in the end, the upgrade (which became the 'Kurnass 2000') was limited to avionics and structural upgrades and the PW1120 died along with the cancellation of the IAI Lavi project.
http://forum.keypublishing.com/attachment.php?attachmentid=9951&stc=1&d=1070365026
Interestingly, BMAC, also working with P&W PW1120s, did some development work on a 'Super Phantom' for the USAF, one of the 'novel' features was a palletized conformal belly fuel tank with hard points and integrated chaff/flare dispensers!

-RP

[27mm]

Thanks Rhino, what a brill looking F4 (as they all are to an ex driver).

[Rhino power]

...what a brill looking F4 (as they all are to an ex driver).
And to plain old, 'phans' alike! :)

-RP

[Old Bricks]

Sorry, bit late in coming into this discussion. Back in the mid-80s I spent many happy hours watching early-model Fulcrums, both Soviet AF and East German, and have no memory at all of smoke being particularly noticeable. Fitters, on the other hand, I do remember producing clouds of the black stuff. Could just be age and decrepitude catching up with me, or that smoke was so normal that we just failed to register it!

[Turbine D]

DirtyProp,
I couldn't find anything much better than the hand sketches/drawing you referenced, but there are a couple of videos that might be helpful to you:

https://www.youtube.com/watch?v=Or6mIaSWZ8g

https://www.youtube.com/watch?v=QPK_eiNng7Q