Aircraft engine question

Miragedriver

Miragedriver

Brigadier
Here is a question for all the aircraft aficionado in Sinodefenceforum. It’s a question that I’ve been researching but haven’t been able to get any conclusive information. As you all know, the Iranians have managed to successfully copy a modified version of the American F-5E called the Azarakhsh fighter. I believe that Iranians have the capability to copy the F-5E, but I would assume that it does not have the industrial capability to produce its own engine (unless they are refurbishing older ones).

My first assumption was that the Iranians placed an AI-222-25 engine, or some derivative of the AI-22 family as the power plant, since it has similar dimensions to the American J-85 engine. However in researching which power plant was utilized, several sites claimed that the original J-85 turbojet engines used in the Azarakhsh were replaced with Iranian made afterburning turbofan J-85 engines with substantial technology from the TF-30 engine.

However isn’t the TF-30 engine the one used on the F-14? This is a large engine compared to the J-85. Proportional scaling of parts, or even “taking” technology from the TF-30 is no easy task. It almost like designing an engine from zero. Look how long the Indian have taken with their indigenous engine for the Tejas. In the end the Indian whet with the F-404/414.

Any first-hand knowledge or theories?
 
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C

chuck731

Banned Idiot
Miragedriver said:
Here is a question for all the aircraft aficionado in Sinodefenceforum. It’s a question that I’ve been researching but haven’t been able to get any conclusive information. As you all know, the Iranians have managed to successfully copy a modified version of the American F-5E called the Azarakhsh fighter. Iran believe that Iranians have the capability to copy the F-5E, but I would assume that it does not have the industrial capability to produce its own engine (unless they are refurbishing older ones).

My first assumption was that the Iranians placed an AI-222-25 engine, or some derivative of the AI-22 family as the power plant, since it has similar dimensions to the American J-85 engine. However in researching which power plant was utilized, several sites claimed that the original J-85 turbojet engines used in the Azarakhsh were replaced with Iranian made afterburning turbofan J-85 engines with substantial technology from the TF-30 engine.

However isn’t the TF-30 engine the one used on the F-14? This is a large engine compared to the J-85. Proportional scaling of parts, or even “taking” technology from the TF-30 is no easy task. It almost like designing an engine from zero. Look how long the Indian have taken with their indigenous engine for the Tejas. In the end the Indian when with the F-404/414.

Any first-hand knowledge or theories?
Click to expand...

No first hand knowledge. But j-85 is a fairly primitive turbojet, not turbo fan, engine initially conceived as a cheap engine, easy to manufacture, using no special or exotic materials, and suitable for target drones. It is probably one of the least demanding jet engines in the world to manufacture.
 
thunderchief

thunderchief

Senior Member
By all accounts and pics , they use refurbished J85 for both Azarakhsh and Saeqeh . Engines are cannibalized from older F-5s , majority of parts could be produced in Iran but not all . It is possible they imported some of the engines clandestinely from other sources , but not much . That is way you have a very limited number of those fighters built .

Btw , there were rumors of Iran importing RD-33 to convert those planes to single-engined fighters , but so far I didn't see any picture of it .
 
Miragedriver

Miragedriver

Brigadier
chuck731 said:
No first hand knowledge. But j-85 is a fairly primitive turbojet, not turbo fan, engine initially conceived as a cheap engine, easy to manufacture, using no special or exotic materials, and suitable for target drones. It is probably one of the least demanding jet engines in the world to manufacture.
Click to expand...

Sorry about the turbofan slip. Yes it is a fairly simple turbojet that was used in early target drones. However, that was the early (and simpler) J85-GE-1 and 2. These engines were small 17” diameter as compare to the J85-GE-21 use on the F-5E which is closer to 23” in diameter and produces about a third more thrust without the afterburner. It is a more complex engine that the early models.

Copying (or license building) an engine is no easy feat. The Romanians had a license to manufacture the Rolls-Royce Viper Mk 633-41 turbojet for the J-22 Orao and suffered may problems with engine reliability. Of course there were other factors to consider, since they were building the engines and aircraft clandestinely from the Soviets at the time. Not to dissimilar to Iran with the current embargos.

It maybe as Thunderchief has mentioned that they are just refurbished “old” engines with parts obtained on the black-market.

I was just curious about the engine situation and how the Iranians “may have” found and replacement for the small but powerful J85. But it seems that the “new” aircraft and engines are just a rebuild of their existing F-5E fleet.
 
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Miragedriver

Miragedriver

Brigadier
thunderchief said:
By all accounts and pics , they use refurbished J85 for both Azarakhsh and Saeqeh . Engines are cannibalized from older F-5s , majority of parts could be produced in Iran but not all . It is possible they imported some of the engines clandestinely from other sources , but not much . That is way you have a very limited number of those fighters built .

Btw , there were rumors of Iran importing RD-33 to convert those planes to single-engined fighters , but so far I didn't see any picture of it .
Click to expand...

That would be interesting to see, since the RD-33 is a larger engine than the F-404 used on the F-20/F-5G aircraft.
 
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