Restart engine in flight tutorials?

[Stratos]

I'm getting frequent engine quits, specially on hard maneuvers while A-G attacks, is there a tutorial or a guide to learn how to restart the engine again?

Thanks!

[Buzzles]

The manual is located here:

...\Eagle Dynamics\DCS World\Mods\aircraft\MiG-21BIS\Doc

Page 162, which is 2.4 Engine Relight of the Emergency Procedures. There's not much to do aside from closing the throttle, turning on engine relight and then reintroducing the throttle.

 

If you keep suffering engine flameouts, you might want to look at the rules for engine use in the manual on page 35, especially around 0 and negative G flight.

The engine in the '21 doesn't like negative G much but can tolerate it in short periods; it positively hates 0g.

Edited August 2, 2015 by Buzzles

[PiedDroit]

You need to:

- idle throttle

- switch the emergency air start ON (up)

- monitor the rpms while the engine restarts

- apply throttle when rpm > 30%, check engine operation

- switch emergency air start OFF (down).

 

From the manual (p 162):

Proceed as follows to relight the engine:

- set the throttle lever at SHUT-OFF;

- turn on the AIR RELIGHT (LV34, in-flight engine start-up) circuit breaker and make sure that

the relight system is on, referring to illumination of the SWITCH OFF IGNITION light in the

panel (RV70).

At any given altitude when the LP rotor speed is equal to or in excess of 30%, shift the throttle lever

to any required non-reheat power setting without any delay; then the engine will accelerate to the

preset power setting, up to the FULL THROTTLE setting, in not longer than 25 s.

The relight of the engine is monitored by increase of the engine rpm and specific sound of the

running engine. The jet-pipe temperature grows slowly; therefore it cannot be regarded as a sure

symptom of engine relight. Once the engine has picked up the idle speed, smoothly move the

throttle lever to FULL THROTTLE check the engine for normal running then cut out the AIR RELIGHT

(LV34) circuit breaker.

If the engine has failed to get relighted, cut out the AIR RELIGHT (LV34) circuit breaker and set the

throttle at SHUT-OFF; then make another relighting attempt.

Edited August 2, 2015 by PiedDroit

[JNASova]

And keep the speed >500

[grunf]

To avoid engine shutdown:

Engine run at FULL REHEAT and SECOND REHEAT at airspeeds in

excess of 1000 km/h at low and medium altitudes is allowed as long

as fuel amount in tanks is at least 800 L

20. Negative g-loads may be developed for not longer than:

(a) 15 s at non-reheat engine settings;

(b) 5 s at reheat settings;

© 3 s at second reheat setting.

21. Flight with g-loads approximating zero (±0.2 g) should not last

for longer than 1 -2 s.

WARNING Negative or near-zero g-load flight is allowed provided

the tanks contain at least 500 L of fuel

[KansasCS]

Restart engine in flight tutorials?

 

I have to add that yesterday my engine quit on me and I couldn't restart it, even after going into idle and engaging in-air-restart repeatedly. I still had heaps of fuel left, too.

[1.JaVA_Platypus]

For me, it is one of those quirks that makes me love the MiG-21. Luckily we are not real MiG-21 pilots with a flame-out! Everyone once in a while, the engine quits on you. It never happens in a suitable moment. And sometimes, it doesn't want to restart. How many restarts do you get anyways? I think the second time the engine quits, your chances of restarting are a lot less.

[Ryan Legend]

Also putting the anti surge doors switch on manual while you're restarting the engine in mid-air could help. Just don't forget to switch it back to auto when you're done.

 

If you exeed the IAS speed limit of 1300 Km/h to often in your flight, you might damage your engine. Wich results in being unable to restart it again.

[Nooch]

I have to add that yesterday my engine quit on me and I couldn't restart it, even after going into idle and engaging in-air-restart repeatedly. I still had heaps of fuel left, too.

 

I guess because your speed was too low. It happened to me once and I was very surprised it didn't want to restart. Just dive to get some speed and it should work fine.

[OnlyforDCS]

Im betting the OP (and a lot of you who are having problems) is pulling a lot of negative G's. I have never had a flameout or engine failure in the Mig21 but I take care to execute maneuvers properly, for example I roll on my back before pulling positive G's to line up on a ground target before rolling right side up. I also take care not to exceed the speed limitations of the engine at low altitude.

[Ryan Legend]

I wonder, did the earlier MiGs have the same negative G's problem too? Like the '15?

[Art-J]

Well, every plane has this problem, the question is how long can You operate under neg G. The -15's engine is not reheated and not as thirsty as R25, so it can work inverted for "impressive" 15 seconds (according to the manual, I never tested it with stopwatch).

[311Gryphon]

I know this isn't that difficult of a procedure and is well documented here and easy to follow, but for some reason I really like testing in flight engine restarts and I made a video in case anyone just wants to see it.

 

 

Thanks!

[QuiGon]

For me, it is one of those quirks that makes me love the MiG-21. Luckily we are not real MiG-21 pilots with a flame-out! Everyone once in a while, the engine quits on you. It never happens in a suitable moment. And sometimes, it doesn't want to restart. How many restarts do you get anyways? I think the second time the engine quits, your chances of restarting are a lot less.

 

I would also like to know what impacts the chances of restarting the engine in flight? Because I often can't get it back to live after my engines quits for the 2nd time.

[Nerd1000]

I would also like to know what impacts the chances of restarting the engine in flight? Because I often can't get it back to live after my engines quits for the 2nd time.

 

The mid-air restart function uses (IIRC) a tank of oxygen to relight the engine. If you use up too much on the first try then you won't be able to relight the engine a second time. It also won't re-start when you are traveling at supersonic speeds or less than 550 km/h IAS.

[QuiGon]

The mid-air restart function uses (IIRC) a tank of oxygen to relight the engine. If you use up too much on the first try then you won't be able to relight the engine a second time. It also won't re-start when you are traveling at supersonic speeds or less than 550 km/h IAS.

 

Alright, makes sense. Thank you for clarifying this.

 

Btw, since I'm not really an expert in this field, what prevents me from just doing a normal engine startup in the air?

[Nerd1000]

Alright, makes sense. Thank you for clarifying this.

 

Btw, since I'm not really an expert in this field, what prevents me from just doing a normal engine startup in the air?

 

I'm not sure. Maybe the igniter needs ground power to work?

[QuiGon]

I'm not sure. Maybe the igniter needs ground power to work?

 

I'm always starting the engine without aksing the ground crew for ground power. As far as I know the startup process includes some kind of APU, that ignites the engine. That's what the switch on the left wall panel next to the fire extinguisher switch is for. You can't start the engine without it.

[Nerd1000]

I'm always starting the engine without aksing the ground crew for ground power. As far as I know the startup process includes some kind of APU, that ignites the engine. That's what the switch on the left wall panel next to the fire extinguisher switch is for. You can't start the engine without it.

 

The 'APU' is is mislabeled- its actually the alternator. I suspect that the ability to start without ground power is a bug because whenever I've done it the ASP has refused to switch on.

[domini99]

But.. In real life, can the mig be started without usage of ground power?

[portman]

And keep the speed >500

 

As far as I remember, RL manual also states that you have to be below 10.000 m.