Question on compressor stalls

[vadupleix]

Hello All,

 

I was flying at 27000-29000 ft at M1.4 today (on my way home after a zoom climb, if you wonder why I’m so fast at this altitude) and I put my throttle at idle position. Then I hear a “Bang” noise, then another one after about 30 seconds, then repeat every 30 seconds-ish. There’s no cockpit shaking nor stick shaking (I’m using a FFB stick), just this “Bang” noise. It goes away if I push the throttle back to mil position.

 

I’m not sure if this is a compressor stall? If so, how is that possible? Because in my understanding the engine won’t go below certain power setting (possibly mil power?) when supersonic, regardless of the throttle position. In fact I don’t observe any change in my engine RPM/TIT/FF indicator when I move the throttle between idle and mil.

 

Would love to know the reason behind this! Thanks in advance.

[draconus]

Have you messed with any of these switches: Throttle temp, Throttle mode, Inlet ramps, Airstart, Eng mode?

[vadupleix]

Have you messed with any of these switches: Throttle temp, Throttle mode, Inlet ramps, Airstart, Eng mode?

 

Negative.

[BonerCat]

If you've taken any battle damage, it could've messed with your engine and inlet systems, but that's the only thing i can really think of

[grant977]

Ra do failures on? I had the starboard engine controller fail once putting it in secondary mode 5 mins after leaving the boat and got into compressor stalls.

[fat creason]

You were most likely in SEC mode or had some problem with the AICS, but not enough info here to really tell

[r4y30n]

That was my first thought when stumbling on this thread. The manual (both HB's and NATOPS, if I recall) suggests that any kind of hiccup that can happen on the F110 will only happen under SEC or otherwise degraded function. Seems like GE knew what they were doing when they designed these engines.

[vadupleix]

You were most likely in SEC mode or had some problem with the AICS, but not enough info here to really tell

 

Is there a possibility that something was damaged during the zoom climb? I was in full burner climb from 40000 to 100000 ft and retarded throttle only after I reached peak altitude, will that cause any damage to the engine?

[ChockP51]

I got some "bang" compressor stall too. Happened occasionally when I dive from high altitude with throttle idle and pull some moderate G (3 to 7 g-ish) at around Mach 1.2-1.4. Engine operate in PRI mode and Ramp is not stow.

[r4y30n]

What's your RPM? Did it actually drop to idle or did it hold near MIL?

[ChockP51]

Around mill rpm. Idle lockup work flawlessly.

[vadupleix]

What's your RPM? Did it actually drop to idle or did it hold near MIL?

 

Mil for me as well

[Scrape]

Had this been real life it's very possible that it could have been a compressor stall. Compressor stalls can and do happen for a myriad of conditions on fighter jets. A compressor stall doesn't mean anything broke, or had degraded performance. It doesn't mean the engine was damaged before or after. I suspect that HB did their due diligence when coding, and that means certain conditions make the engine "unhappy" are possible in DCS. Also mirroring a bit of real life, these conditions may prove difficult to reproduce. I've encountered a couple myself in the sim, and I think it's pretty cool.