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Loss of left engine power lead to loss of right engine


Rongor

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Yesterday, my left engine shut down after suffering from complete loss after oil pressure had dropped to zero. "No problem" I thought and pulled the yellow throttle lever left of me to the upper position, for compensating the loss of left engine power by maximizing power of the healthy right engine.

My rotor pitch indicator was at around 10, so in a pretty regular power regime. Yet only after a few seconds of the left engine still winding down, the right engine started to loss rpm too and soon it was following the left engine in to complete power loss, albeit it appeared to be struggling to keep power but ultimately slowly went down (within half a minute or so). 

 

I was surprised by this. I'd expected to continue with the healthy right engine. Yet it literally behaved like it was wasting all its energy to keep the left engine going to. As we know, this isn't technically possible as these turbines work free and have no direct connection.


Any ideas why my right engine might have been affected in this case? Right engine parameters (oil pressure, temps) were just fine. 

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1 hour ago, Rongor said:

Any ideas why my right engine might have been affected in this case? Right engine parameters (oil pressure, temps) were just fine. 

 

It sounds like whatever caused the left engine to fail caused the right to fail. An engine failing can't be the cause of the other doing so. You didn't mention anything about receiving hostile fire, so what conditions were you flying?

Were you flying high or in cold temps/precipitation that could lead to icing? Did you receive any Ekran messages about turning on anti-icing systems?

Did you ensure your EEGs were switched on during start-up? Did you get Ekran messages about engine vibrations?

Were you running low on fuel?

Did you have random failures enabled?


Edited by Raptor9
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7 hours ago, Raptor9 said:

You didn't mention anything about receiving hostile fire, so what conditions were you flying?

Were you flying high or in cold temps/precipitation that could lead to icing? Did you receive any Ekran messages about turning on anti-icing systems?

Did you ensure your EEGs were switched on during start-up? Did you get Ekran messages about engine vibrations?

Were you running low on fuel?

Did you have random failures enabled?

 

You are right, I didn't mention all this and there are possibly other dozens of potential issues. In fact I didn't mention any of these because none of these factors were contributing to the described situation😉

The left engine was put out by hostile small arms fire. After that, all external factors remained constant and had no further effect on what was happening. So it is no question why the left engine failed. I was focusing on the correct actions to continue flight with OEI. Sadly it didn't work because the healthy engine decided to lose power after putting the throttle lever to max. This last fact is the only thing I was questioning. Sorry if I didn't make myself clear with this.


Edited by Rongor
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From what i remember flying the KA-50, it does not fly well one 1 engine with weapons.  It sounds like that the loss of the left engine along with the state of your collective just bogged down the right engine tell where you crashed. Honestly the best way to survive is after losing a engine is to take and jettison the weapon stores and fly home.     It may be a two engine helicopter, still needs the power of 1.5 engines to really be able to continue flying.    I have flown back home plenty of times on one engine. It takes alot more work with power management of the collective to make it back.  Pull to much collective and you bog the engine down and sink.

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7 hours ago, Rongor said:

So it is no question why the left engine failed. I was focusing on the correct actions to continue flight with OEI. Sadly it didn't work because the healthy engine decided to lose power after putting the throttle lever to max. This last fact is the only thing I was questioning. Sorry if I didn't make myself clear with this.

 

Well Ka-50 has 2x2400shp so now you have almost 2400shp less, after losing one engine you did the correct thing and placed throttle lever into emergency this grants you a bit more power but helicopter is still extremely under powered, next thing to do would be to jettison missile pods/fuel tanks and probably even fire all Vikhr with that red emergency ATGM jettison switch (un/fused- switch that controls this is next to ATGM jettison) into safe direction or enemy territory 😄 while doing these things never let the helicopter get slower than 80km/h, you can't hover with one engine. Rolling landing is preferred, "hover" landing can be done but it will more resemble autorotation landing.

By flying with forward speed of >80km/h you will see that you can hold speed/altitude and even climb you can also look at your EPR gauge and you will see that working engine is really pushing it so RTB should be done ASAP.

One more thing, raising the collective should be done with caution when you lose one engine, because at higher collective position one engine will be unable to keep rotor RPM in the allowed range causing even more trouble VRS and also AC generator will stop functioning which will in turn shut down some of the systems and others will be powered via inverter until rotor RPM is restored. So constantly keep rotor RPM in check.

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Concur with the above. Loss of one engine should itself lead to another being lost. With governors on even max throttle also shouldn't lead to overheating. There's definitely damage modeled in DCS that worsens over time, i.e. you lose an engine a or hydraulics fully only some time after taking damage. My guess would be the right engine did actually take damage, but not enough to knock it out immediately like your left engine. This is assuming there's no icing, dust or hard knocks that took it out.

I'm also pretty sure damage can cause engines to have weaker output instead of just on-off, so sometimes it's hard to stay up even with everything shed/jettisoned/launched and lower fuel - you'll have to gauge your lift after dumping to see if you can still keep afloat. And pop gear earlier if you think you'll lose hydraulics.

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I had a similar situation but in the Mi8. I lost an engine to ground fire and flew on one engine. I noticed the functioning engine was operating at high temperature, the power indicator ( the two yellow needles for each engine) was extremely high and rotor rpm was 110% in forward level flight. I tried to roll back the throttle to reduce rotor rpm and engine temp, but it didn’t respond. Coming in on short final at 40 kmph and at 50m, the engine quit, resulting in a very hard but survivable landing. 

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in the ka-50 and mi-8 the TV3-117 engines automatically go to max rated power when one of the engines fails.

you can run the remaining engine for up to 60 minutes in this state.

but for every minute after the first 6, this reduces the service life of the remaining engine. 

As max rated is above take off power the remaining engine should show higher than take off on the engine pressure ratio/indicator gauge.

and PTIT should be high (maximum 990)

Rotor RPM should remain the same. if its high or low this will reduce the time you have based on limitations in the rotor system. above 103% should be 20 seconds..

below 88% and its 30 seconds.

If the Rotor RPM stays high/low then you have lost more than just an engine. (governor system)

land ASAP.

 

 

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If I'm on only one engine I take advantage of ground effect and translational lift by going low to the ground and above ETL speed but not so fast I'm above optimum ground effect.  Not a bad idea, as others have said, to jettison stores.  Thankfully DCS BS has jettison, though I've rarely ever done that, to be honest.  Go easy on the collective.  It's hard to know in the sim if there is damage to common systems that might affect both engines or if you just over-stress the other engine, but on one engine I usually try to be gentle on the collective and RTB.  Sometimes I make it back, sometimes I don't.  Sometimes I don't bother trying to RTB and just keep on fighting.

The constantly weird rotor RPM after engine loss indicating damaged governor is very interesting info.

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