Mig-21SMT and derivatives engine?

[lancer21]

Acording to airwar.ru, the SMT has an R-13F-300 engine with an emergency regime at low alt and mach speed that is suposed to deliver and extra 1900kgf over the normal aftreburning rating( that is , its either 6490+1900=8390 or its 6600+1900=8500kgs , according to the 2 versions of the R-13-300 thrust circulating around! which one is correct anyway , www.mzak.cz says 6600kg ...).

Also according to airwar , there was this "MFT" which was suposed to have an R-13M-300 with 8800kgf emergency thrust...and there's at least another russian site which quotes same value...

There is also reference to an R-13F2-300 on the web , rated at 7200kgf...and you can find reference of this R-13F2-200 in Gordon's book , tho no detail about the thrust...

Does anyone can shed some light over these engines, right now it looks quite confusing about which is which, and on which Mig-21 version were they used ...the R-25-300 is somewhat better known , its suposed to have 9900kgf in emergency mode at low alt and mach1 , however long time ago i've read something about "only" 8600kgf , in a hungarian publication - something about the intake design/cone ? couldnt translate the whole sentence back then...-called Top Gun , if any of you know it ...

Thank you!

 

[mrdetonator]

The article called R-13F-300 from writter Ing. Marián Hocko, PhD. on mzak.cz website is a little misunderstanding, there should be written R-13-300 only. The engine R-13-300 thrust on afterburner is stated 6600+65-130 kp.(engine manual). The R-13F-300 was a small modification of the R-13-300 used with heavier SMT, MT and had a modified nozzle with flame holders and additional fuel pump for the so called "emergency regime". The R-13F2-300 was installed in Su-15TM.

 

[lancer21]

Thanks for your reply Mrdetonator!

Yes i saw the note left by martinez in the shoutbox on mzak.cz website...so that would meen that the emergency thrust is 8500kgf max ,and that for instance the operational limits of the R-13F in emergency mode are roughly same as for R-25-300, ie , no more than 3 mins max , 1 minute in boost mode equal 1 hour on the log book etc...wonder where that 6490kgf value came from ( and also one the most interesting part afaik is that the 6600 kgf thrust of the R-13 was "guessed" right from the seventies in the west!)

Interesting info regarding the Su-15TMs , i thought they have regular R-13-300 ...i know Gordon mentions about the prototype Su-15bis , with two R-25s...which also speaking wich Gordon mentions that some sources say its actually 6850kgf in afterburner and 7100kgf in boost mode!

Of course the manuals reign supreme... ;D

 

[overscan (PaulMM)]

MiG-21MF with R-13-300 (and its manuals) was exported from 1970 onward, so its not surprising at all....

 

[mrdetonator]

so that would meen that the emergency thrust is 8500kgf max ,and that for instance the operational limits of the R-13F in emergency mode are roughly same as for R-25-300, ie , no more than 3 mins max , 1 minute in boost mode equal 1 hour on the log book etc...wonder where that 6490kgf value came from ( and also one the most interesting part afaik is that the 6600 kgf thrust of the R-13 was "guessed" right from the seventies in the west!)

Later produced engines R-13-300(izd.95) had three afterburning regimes, the MF "Malaya forsazh-small afterburner", the 1F "prvaya forsazh-first stage afterburner" and the 2F "vtoraya forsazh" in english "second stage afterburner". Added regime "2F" was triggered automatically and only when engine throttle lever was set to the afterburner far-end position (engaged 1F ) and the aircraft flying at an altitude equaling speed Mach =>1.5 . Then the engine control automatic increased LP compressor RPM to 103%, set engine nozzle diameter to max and the main fuel pump regulator NR-54 supplied more fuel with increased output pressure giving an extra thrust boost for better intercept characteristics. The disadvantage you could not switch it on during take-offs, subsonic speed during manuevering,...

The Mig-21SMT featuring the R-13F-300(izd.95F) had been equipped with a switch in front of the engine throttle lever saying "CH.F. - Chrezvychayny Forsazh", which supposedly could be used during take-offs to help heavier SMT to get airborne or during maneuvering at speeds around Mach1 helping with max. surplus 1900kgf over the normal afterburning thrust. But the principle of thrust increase is almost the same as in case of R-13-300, except the additional(or modified) fuel pump mentioned before.

 

[Fox_One]

Interesting, didn't knew that. I thought that MiG-21bis was the only version with the Ч.Ф. switch.

 

[lancer21]

so that would meen that the emergency thrust is 8500kgf max ,and that for instance the operational limits of the R-13F in emergency mode are roughly same as for R-25-300, ie , no more than 3 mins max , 1 minute in boost mode equal 1 hour on the log book etc...wonder where that 6490kgf value came from ( and also one the most interesting part afaik is that the 6600 kgf thrust of the R-13 was "guessed" right from the seventies in the west!)

Later produced engines R-13-300(izd.95) had three afterburning regimes, the MF "Malaya forsazh-small afterburner", the 1F "prvaya forsazh-first stage afterburner" and the 2F "vtoraya forsazh" in english "second stage afterburner". Added regime "2F" was triggered automatically and only when engine throttle lever was set to the afterburner far-end position (engaged 1F ) and the aircraft flying at an altitude equaling speed Mach =>1.5 . Then the engine control automatic increased LP compressor RPM to 103%, set engine nozzle diameter to max and the main fuel pump regulator NR-54 supplied more fuel with increased output pressure giving an extra thrust boost for better intercept characteristics. The disadvantage you could not switch it on during take-offs, subsonic speed during manuevering,...

The Mig-21SMT featuring the R-13F-300(izd.95F) had been equipped with a switch in front of the engine throttle lever saying "CH.F. - Chrezvychayny Forsazh", which supposedly could be used during take-offs to help heavier SMT to get airborne or during maneuvering at speeds around Mach1 helping with max. surplus 1900kgf over the normal afterburning thrust. But the principle of thrust increase is almost the same as in case of R-13-300, except the additional(or modified) fuel pump mentioned before.

Thanks , great info Mrdetonator!

Regarding the R-25 , stumbled upon this page on the net ...

http://militaryforces.ru/weapon-1-10-59.html

Very interesting datas there...can it be corelated with the engine's manual ? the site seems to be an oficial one , maby belonging to Rosoboronexport...

Thanks.

 

[mrdetonator]

Regarding the R-25 , stumbled upon this page on the net ...
http://militaryforces.ru/weapon-1-10-59.html
Very interesting datas there...can it be corelated with the engine's manual ?

from R-25-300 manual

 

[lancer21]

Brilliant , thanks alot!