Mid-air engine shunt/shutdown? What happened?

[KilledAlive]

I was performing a high speed dive going around Mach 1.2, leveled out, and I followed it up with a long, swooping, climbing left turn to gain some altitude and maintain my speed. Suddenly, towards the top of the curve where I was planning on descending or leveling out, a loud "THUNK" was heard, a puff of exhaust emerged from my tail, and I completely lost engine power. This is the first time this had happened to me without pulling some serious negative G's or doing something else wacky to the air frame. This is also the first time for me that my engine produced that exhaust puff as well. Sorry, I don't have a Tacview of it, but I was just wondering what other conditions an engine shunt and loss of power can occur. I was able to re-light, so it wasn't complete engine failure.

[Lixma 06]

Happened to me a few times - what's happening is that while from your perspective you're performing a gentle turn/wing-over, from the engine's perspective you're entering a zero-G parabola - a bit like the vomit comet they use to train astronauts.

[Frederf]

Engine seems to hate 0±½g more than it g < -1. The higher the fuel rate the sooner the dispenser tank runs dry and it takes ~30s to refill.

 

Also confirm <1300 km/h and <M2.1 as those kill the engine every time too.

[Satarosa]

I find that currently the engine runs out all too often it's probably not like that in reality the MiG-21bis had a reputation for being reliable !

[KilledAlive]

Happened to me a few times - what's happening is that while from your perspective you're performing a gentle turn/wing-over, from the engine's perspective you're entering a zero-G parabola - a bit like the vomit comet they use to train astronauts.

 

Yeah, I guess in the same way that the engine hates pulling negative g's, it also hates zero g maneuvers as well.

[Frederf]

I tried as many variables as I could think of and got ~7-18s time to flameout when G<+0.5. I never had flameout G>+0.5.

 

The real manual mentions 15-3-2 seconds for MRT, 1st, 2nd afterburner respectively due to fuel feed from dispenser tank. Test DCS:

 

Idle -1g, 18s

MRT -1g 10s

1st -1g 8s

2nd -1g 8s

 

It's clear from testing that the actual quantity in the dispenser tank isn't being persistently tracked for this purpose as the time to flameout -1s can elapse, 1g flight very briefly resumed, and the process repeated when no time has been given for the tank to refill.

 

The region around -0.2 to +0.2g seems to be the most sensitive which should be due to oil feed but the engine cuts out presumably by fuel before the oil pressure drops to an unsafe level (the oil pressure does drop steadily in this condition).

[QuiGon]

Yeah, I guess in the same way that the engine hates pulling negative g's, it also hates zero g maneuvers as well.

It hates ~0g even more than negative g.