cx777

Red EPR EICAS

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I'm conducting some test flights and I have noticed that on the PW variant the TOGA is exceeding the engine EPR (1.54) it goes to (1.55) and goes red(while rotating). I followed the takeoff procedures.(move throttle to 50% engage TOGA then move throttle forward once thrust ref is displayed on the pfd). However if I derate power on the thrust lim page it does not happen 1.46 EPR. My throttle is calibrated and are not moving while all this is happening. Also I have not noticed this the GE or RR engines.

Neil Vince

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Gents,

 

There are umpteen protections against this. One would have to lean on F4 with his elbow to red line. Can you please open a ticket with support and state temperature and altitude that you have seen this ? Also are we talking -ERF and 4062 engines or -400/-F regular and 4056 engines ?

 

Thank you

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Gents,

 

There are umpteen protections against this. One would have to lean on F4 with his elbow to red line. Can you please open a ticket with support and state temperature and altitude that you have seen this ? Also are we talking -ERF and 4062 engines or -400/-F regular and 4056 engines ?

 

Thank you

It's happening on the 400 and 400F PW models. Haven't really tested the ERF.

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Hi,
It seems I have the same issue. I have just took off with United 747-400 PW4056 engines, this is my first flight with PW engines.

I took off as usual, throttle to ~50% then press TOGA, push my throttle to 100%, EPR went above and got red boxes. After take off I press CANC to get rid of the red box but this is the first time happen to me with the new Queen. I did everything the same as I have done since I bought the aircraft.
I will do another take off later after I finish this flight.
Hoang Le

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Also I have not noticed this the GE or RR engines.

You wouldn't notice it with the General Electric engines because General Electric does not use EPR, so it would be impossible to have a red EPR indication for a gauge that doesn't exist.

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I have had this happen with R.R.(EPR)and G.E.(N1) engines on pushing TOGA at approx 50% EPR or N1 and advancing throttles once THR REF appears.If I carefully advance the throttles the EPR or N1 just goes above the red line and the THR REF annunciation changes to SPD. Once in the air the annunciation returns to THR REF. If I advance the throttles quickly I get the red box appearing. I have presumed that this is due to spiking from my four lever throttle quadrant. I have another throttle quadrant that I successfully use with the 737 NGX and the 777. Am going to use this

quadrant next time I fly the 747 and assign one lever to operate all four throttles. Hopefully this will solve the problem. I will post the outcome in this thread.

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This happened to me 2 hours ago out of Quito on my current flight, advanced throttles gently, pressed TOGA, flap 20 takeoff no de-rate. real weather. 747BCF pw engines. first time I used no de-rate and my EPR still has the red boxes in cruise. - David Lee

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Hi,

For all of these who have the problem, how did you set the A/t override option in the CDU? Mine is set to IN HOLD MODE ONLY and I don't recall having had this issue (though I may have missed it, I seldom use full TO thrust).

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30 minutes ago, Budbud said:

Hi,

For all of these who have the problem, how did you set the A/t override option in the CDU? Mine is set to IN HOLD MODE ONLY and I don't recall having had this issue (though I may have missed it, I seldom use full TO thrust).

set to never and I have not had an issue in the 777 or 747 before, first time non de-rated takeoff and I got the redline - David Lee

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Won't this be related to the more times highlighted bug of the actual N1 constantly increasing by itself during HOLD mode at takeoff (when it should not change, unless the pilot moves the throttles), so exceeding the takeoff reference N1, with the danger of an engine exceedance?

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53 minutes ago, jgoggi said:

Won't this be related to the more times highlighted BUG of the actual N1 constantly increasing by itself during HOLD mode at takeoff (when it should not change, unless the pilot moves the throttles), so exceeding the takeoff reference N1, with the danger of an engine exceedance?

I don't think so. From what I've noticed, the N1 might increase slightly, but the EPR doesn't change when this happens.

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Just had a derated T/O from VTCC  go rogue in the red. 25% gas in the tanks and few PAX. I assume this is now something the great folks @ PMDG are looking at? 

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On ‎3‎/‎26‎/‎2017 at 6:06 AM, jgoggi said:

Won't this be related to the more times highlighted bug of the actual N1 constantly increasing by itself during HOLD mode at takeoff (when it should not change, unless the pilot moves the throttles), so exceeding the takeoff reference N1, with the danger of an engine exceedance?

No. This is not at all related to that issue. As I've noted several times in responses to you, that issue is protected within the AT margins. The issue seen here is caused by hardware positions overriding the AT.

36 minutes ago, funkyhut1 said:

Just had a derated T/O from VTCC  go rogue in the red. 25% gas in the tanks and few PAX. I assume this is now something the great folks @ PMDG are looking at? 

Yes.

...but as I'll always note here, if you find something, please report it via the official avenue. It's troublesome to me when I see people post here and assume/hope we'll happen upon it. Posts here aren't guaranteed to be seen. Tickets are. I'd hate for something to go floating off into the ether because someone didn't use the official support avenue to report something. A lot of us on the team were scattered about this weekend. I ignored the forum entirely from about Thursday until late last night. I can state categorically that I did not read every single thread, or even every post within those threads.

  • Upvote 1

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I had the same problem, however, when I changed A/T Derate to 1500 ft instead of at CLB1 in the T/O REF page the problem disappeared. Don't know if this has already been tried, but it worked for me. 

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On ‎3‎/‎25‎/‎2017 at 11:37 PM, 777200lrf said:

This happened to me 2 hours ago out of Quito on my current flight, advanced throttles gently, pressed TOGA, flap 20 takeoff no de-rate. real weather. 747BCF pw engines. first time I used no de-rate and my EPR still has the red boxes in cruise. - David Lee

Not to hijack the thread, but are you flying out of the old airport or the new?  And in the event it is the new what scenery are you using?

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On 8/29/2017 at 4:46 AM, FLHXRider said:

Not to hijack the thread, but are you flying out of the old airport or the new?  And in the event it is the new what scenery are you using?

I recommend north_central_ecuador_v2.zip in the library here

It uses default buildings but much better than nothing and for free

Make sure you have a mesh product I use FreeMeshX - David Lee

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I have this issue too. Noticed on -400PW (at least).

EPR goes to red after takeoff on one (or two) engines, and stay always in red, even with lower values

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4 hours ago, jasoncardeira said:

and stay always in red, even with lower values

Yeah, once the limit it exceeded, it's going to stay that way until you bring it in to have it inspected. Potential damage to the engine is going to need to be looked at by maint, so the plane isn't going to let you forget it just because the values have been reigned in.

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I've had this issue with PW4056 engines as well.

Take off was normal, then as power was reduced to CLB the A/T kept fluctuating thrust on Eng 1+2 and alternating with thrust on Eng 3+4. EPR went into the red.

I disconnected A/T, manually set CLB power and the issue was gone.

This doesn't happen on RB211 or non EPR engines.

It happened multiple times with the 4056' from 'benign' airports such as TNCM and EHBK.

Hope this helps the troubleshooting process.

If not, I can probably create a video.

Regards

Mark Foti

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I have also experienced this issue and I am 100% certain it was not my error.

It has occurred in both climb and in cruise (I have more than 1,000 hours in the PMDG 744 at this point). I have seen this issue maybe 6 or 7 times. I have seen it happen in all the 744 engine types.

I suspect it is related to activesky weather changes. The issue is most likely happening at weather transitions in the activesky weather world. I have seen it happen when I entered light-moderate turbulence at cruise altitude. Time acceleration may also exacerbate the problem.

I have also seen it happen when performing step climbs (no time acceleration when it happened).

I generally fly the 744 at near maximum payload but with medium to light fuel loads, my typical flights are in east Asia and take less than 3 hours from clock on to clock off.

My throttle override setting is set to off, my throttles and yoke are disabled during autopilot flight.

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This issue happened after update the PMDG 744, it was working fine before the update.

MoDez

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