Emergency Afterburner

[Tetra]

Can somebody explain the purpose of the emergency afterburner? The only line I can find in the manual regarding it (aside from it's switches and a section about inverted flight) is that it was added to improve thrust to weight ratio at lower speeds but I am unsure as to if/when I should be employing it? Thanks for any pointers.

[ff4life4]

Use it when you need more power! I believe it was added so the Mig could compete better in a dogfight.

 

Manual says to only use it in 3 min interval. After a 30 second break, you have another 3 min and keep repeating.

 

Edit. It's a 30 second break. Not 30 min

Edited September 22, 2014 by ff4life4

[TwilightZone]

.......was this used for heavy weapon payload takeoffs?.....not sure on this but i believe in one of the Bunyap test videos he talked of its use a bit....not sure which video though

[Tetra]

Use it when you need more power! I believe it was added so the Mig could compete better in a dogfight.

 

Manual says to only use it in 3 min interval. After a 30 break, you have another 3 min and keep repeating.

 

Ah that makes sense many thanks for the explanation :thumbup:

 

.......was this used for heavy weapon payload takeoffs?.....not sure on this but i believe in one of the Bunyap test videos he talked of its use a bit....not sure which video though

 

Not seen the video but from what you're describing I believe that would be the SPRD you can attach which gives you rocket assisted takeoff.

[ff4life4]

I managed to use it to kill an f15 on the 104th server against a good pilot. I locked him. Hid in a mountain, when he flew over me, full emergency AB and you know the rest.

[TwilightZone]

@Tetra......you are correct.......i was thinking rocket assist takeoff.....:-)

[IonicRipper]

I managed to use it to kill an f15 on the 104th server against a good pilot. I locked him. Hid in a mountain, when he flew over me, full emergency AB and you know the rest.

 

Video or didn't happen :music_whistling:

[ff4life4]

I did it last night. Killed someone called Ace (and some some combo of numbers 9631)

 

I left this morning for a business trip. I'll try to find the track when I get back.

 

Idk if you know Stuge, but he was there when it happened. Ask him for proof :)

 

Edit: Stuge also killed an su-27 sp mig 21 has a chance. Just gotta use solid tactics and attack when you have the advantage.

 

I'd imagine 2 mig 21s working together could have good success against f15s and 27s. Use one as bait, run into a mountain range for cover and then follow up behind him

Edited September 22, 2014 by ff4life4

[IonicRipper]

I'm just pulling your leg ;)

 

Although I would like to see the track!

Edited September 22, 2014 by IonicRipper

[ff4life4]

Believe it or not, I had a few other close calls for getting kills. I was flying in formation with Beaupower for a while, and he got a kill within 2 miles. I locked the tgt on radar, but I lost him behind a mounting and Beau found him first and killed him with the f15.

 

Almost killed a mig 29 but I lost where he was and he got me. That was a close in fight.

 

And had some instances where I got close to other enemy's but when they got in a good killing position they were taken by other friendly fighters.

 

I noticed with the 21 I am much more careful about using better tactics. And only enter a fight when I have a decent chance, on my terms (unless I'm found first :).. which happens a lot lol

 

Edit: so far I have just been flying lown in the dirt, and pointing the radar up often to see if somethings in the distance. I always try to stay near mountains, and if I find a target I'll run and appear from somewhere else and try to find them then. If I guess right I'll require them close in and will then try to get visual and go from there.

 

A lot of its like fishing. Lots of time where nothing happens but then it gets exciting sometimes

 

Enough of giving my secrets away lol.

 

My next goal is to go Frog and Hog hunting

Edited September 22, 2014 by ff4life4

[MauganRa84]

Great to hear ff4life4. Your 21 stories are awesome.

 

Inspires a little more confidence to use the 21 against the more modern birds in DCS online.

 

Well done.

[Allesmor Obranna]

The ChR, or Emergency Afterburner is driven by the NR-44 Additional or Extra Afterburner Feed Pump. The two main feed pumps are the NR-54 for the Idle to Maximal, and the NR-22 for the min to max reheat. So the NR-44 is only for a certain regime, when all specified parameters are together. The inlet pressure is given, the speed is less than supersonic, the pressure altitude is less than 4000 meter and the time limit is 3 minutes.

The switch on speed is somewhere higher than 380 km/h, depending on the ambient pressure.

The Tumansky R-25-300 engine's big achievment is the increased air mass flow and the compressor pressure ratio. You don't think on big numbers, because the high pressure ratios such as 28-33 of the modern engines simply just did not exsist at that time.

The predecessor R-13-300 has pK ~8.6 and app. 60 kg/sec mass flow, while the R-25 has an upgraded first stage LP compressor (21 wider chord blades instead of the 24 narroer ones), so it has pK 9.8 and 68 kg/sec air mass flow.

 

This improvment was enough to increase the max dry thrust from 49 to 51 kN and the max AB thrust from 65 to 75 kN. But here is the ChR regime's big benefit.

When all required parametes are in together and the ChR switch under the throttle is turned up, the NR-44 starts to push the extra fuel to its own dedicated sprayers and the thrust is starting to increasing up to 97kN. It is quite big, since in this point the MiG-21bis has an almost 1:1 thrust/weight ratio.

 

The DCS MiG-21bis afterburner animation is a little bit wrong. The engine flame for the R-25 is normally closer to the AI planes than what Leatherneck did. But when you lit on the Emergency Afterburner, the flame does not change. This is not correct and you can see how the ChR is looking when it is turned on.

 

${1}

 

The solo take off and the solo flight (during the min radius turn) used the ChR.

 

Edited September 22, 2015 by Allesmor Obranna

[QuiGon]

That's some nice info, thank you!

 

Rep inbound :)

Edited September 23, 2015 by QuiGon

[Hadwell]

Well... in DCS, turning on the 2nd(emergency) afterburner below 5000m gives you a big acceleration boost, a higher rate of climb, and allows you to get all the way up till 1400kph IAS, where the engine cuts out and needs to be re-lit, even with missiles and a drop tank.

 

it shuts off by itself if you climb above 5000m, and if you don't flip the switch back to off, it'll turn back on as soon as you dive below 5000m.

 

just keep an eye on your fuel (or lack thereof)

Edited September 23, 2015 by Hadwell