investigating Engine damage after only flying around

[canned_fire]

After a long flight on the 109 (more than 1 hour) I noticed that the engine was not producing as much power as in the beginning of the flight. I could reproduce the event, see track. It is rather simple just fly around at cruise power (around 1.15 ATA) and after about 50 minutes (use time compress) you can hear the engine damage and it producing less power by comparing the airspeeds. An easier way to check that is to “active pause”, and after around 30 minutes you can see the propeller pitch changing to compensate (increasing pitch) the loss of power. Interestingly if you keep a high power 1.25+ this doesn't seem to happen.

 

Can anyone else confirm this?

109 engine failure.trk

[grafspee]

On 11/27/2020 at 2:51 AM, canned_fire said:

after around 30 minutes you can see the propeller pitch changing to compensate (increasing pitch) the loss of power. 

109 engine failure.trk 114.31 kB · 3 downloads

Increased pitch is not symptom of lost of power. Lost of power will result in rapid decrease of prop pitch most likely straight in to minimum pitch. 

Increasing Airspeed or increasing power will induce higher pitch angle of the prop if you haven't touched throttle.

Edited December 6, 2020 by grafspee

[canned_fire]

Ok, can you explain the engine grinding noise at the end of the track? Or the resulting lower speed for the same ATA?

[grafspee]

I noticed lost of power and i noticed decrease in pitch at beginning pitch angle was around 50 and after +30min  at the same power setting it dropped to 41.

Hard to tell what is the reason for this.

Probably Ed is implementing new engine management system and you are experiencing some kind of engine failure.

Edited December 12, 2020 by grafspee

[NineLine]

Track no longer plays back, but I will take control and fly as you stated, will see if I can see what's going on, thanks guys!

[NineLine]

Ok, so this is what I saw, and I didnt use anything like active pause or such, I flew the entire flight on my own. As you stated originally I flew as close to 1.15 ATA the entire flight as I could. at about 1 hour and 10 mins, I did hear what sounded like engine damage noises. I flew with these for a few minutes, what is strange is I didnt see any change in the engine as far as gauges went, I didnt seem to loose any power either. I took the engine up to 1.4 ATA and the sound went away, and I was able to eventually bring it back down to 1.15 and I flew the aircraft until I ran out of fuel. 

 

So for sure something weird is going on, I will send a vid of my flight to the team and see what they can find out. Thanks guys.

[iFoxRomeo]

Perhaps at this powersetting plugfouling starts to creep in. High powersettings clean the plugs again. Maybe the plugfouling starts too soon.

 

Fox

[NineLine]

That's exactly it. I should have known that, but after showing my vid top Yo-Yo he reminded me. SO 1.15 is below normal cruise, and even at cruise you must run some max continuous, he recommends every 15 minutes. So what you are seeing is that the plugs are fouled, and increasing the power should clean them up.

 

 

[canned_fire]

Thanks NineLine for looking into this. According to the table attached, which I think applies to our Bf109K with 605DB engine, 1.15ATA is "economy cruise" which in my interpretation would be normal cruise. I know that ED's Bf109 manual gives 1.25 as "cruise", but the problem with using 1.25 is that it results in a airspeed that requires full nose down stab plus a little of stick forward to maintain level flight, which is uncomfortable during long flights (real or simulated).

 

The only time I have heard of "gunning the engine" is on prolonged descents at idle or long idle on ground, but I have never heard when using cruise settings. But maybe that's how the 109 was in real life, I don't know, I don't read German. It is interesting to know that the 109-G2 (at least) had a handle to clean the plugs, as described in the other attachment. I have wondered if this handle could be #8 on the third attachment?    

[NineLine]

As I am aware this was based on our research, its generally not a big deal unless your are flying a long time on low settings though, so it really shouldnt be an issue, just remember to give her a little extra gas from time to time. Thanks.

[DoctorVixen]

i bought the thing during sale someday, i remember learning to take off and all was fine. but when i take off i a mission like a min after take off the engine just dies.

had this 5 times in a row, als the trim did not work, probably doing something stupid wrong, but it made me lose all interest in this plane. ragequited, unistalled and never touched it since

 

[NineLine]

Just now, DoctorVixen said:

i bought the thing during sale someday, i remember learning to take off and all was fine. but when i take off i a mission like a min after take off the engine just dies.

had this 5 times in a row, als the trim did not work, probably doing something stupid wrong, but it made me lose all interest in this plane. ragequited, unistalled and never touched it since

 

Well if you ever try it again, and experience the same thing, let me know, send me some tracks and I will investigate. Thanks.

[iFoxRomeo]

21 minutes ago, DoctorVixen said:

i bought the thing during sale someday, i remember learning to take off and all was fine. but when i take off i a mission like a min after take off the engine just dies.

had this 5 times in a row, als the trim did not work, probably doing something stupid wrong, but it made me lose all interest in this plane. ragequited, unistalled and never touched it since

 

For me it sounds like this

 

Hint: Prop governor.

It's a great plane

 

Fox

 

[grafspee]

I've never seen someone posting in that way, "After take off in Bf-109, when my speed increase rpm of the engine goes up beyond red line then my engine dies, what am i doing wrong."

It is always like that,"everything is in green, i tried everything but engine keeps dying"

[Reflected]

Since the CEM update my 109 often dies on me too. Not going below 1.0 ATA. I'll try to investigate and post some tracks. Maybe I'm doing something wrong...

[grafspee]

4 hours ago, Reflected said:

Since the CEM update my 109 often dies on me too. Not going below 1.0 ATA. I'll try to investigate and post some tracks. Maybe I'm doing something wrong...

Dies mean prop stops or lost of power ?

[Reflected]

Lose power.

[NineLine]

Yeah if you get a track you know where to find me

 

[Reflected]

I flew around for a while to test and it worked fine.  Will get a track next time it happens.

[Reflected]

I have a track. Did not seem to exceed oil pressure limits. Took off at 1.3 ATA, flew at 1.42 for not more than 30 seconds, did not use MW50 at all, then mostly 1.3. My engine lost power and died soon.

 

109failure.trk

Edited January 23, 2021 by Reflected

[Reflected]

Same issue, I was well within limitations:

 

 

109failure2.trk

[Reflected]

Air start this time. Used 1.4 ATA for about 40 seconds:

 

 

109failure3.trk

[bart]

Weird....

 

I've just been on the AO server and flew around in a K4 for nearly 1 hour, no issues (other than prop keeps disappearing on F2 view!). I was at 1.4ATA almost all the time.

 

Are you guy's sure you have the prop control switch in the rear position?

Edited January 23, 2021 by bart

[Reflected]

Yes, prop is in auto. 

[NineLine]

Thanks I'll take a look at the tracks.