Go around thrust logic?

[tcas_climb 45]

It works fine for me, the thrust mode changes to THR

[jgoggi 65]

Thank you. You have SP1c, don't you? It's really, really strange why it doesn't change in mine, I tried about 100 times, both with and without A/P and it always remains in SPD. Only after touch down, if I press the TOGA again, the mode changes to THR. I can't really figure out where the problem is...

[777simmer 117]

According to FCOM 9.20.12:  "or below 100 feet radio altitude on approach the autothrottle will not automatically activate."  Understand that this refers to the case where A/T is not already activated.

That is actually about the stall protection feature.

Not TOGA.

 

TOGA works up untill touchdown.

TOGA becomes armed with flaps not up or if the GS is captured)

 

If touchdown (bounce) occurs after TOGA has been pressed then TOGA mode stays engaged!

Can someone please explain how the go around thrust works? During landing if I press the TOGA switch it seems that the thrust does not increase or increases just a little in order to keep the airplane maintaining Vref, without a tendency to climb if the A/P is engaged. Further, I read on the FCTM that if I press TOGA  a second time, the thrust should increase to the maximum G/A thrust, but nothing happens if I press TOGA  a second time on the PMDG 777.

Thanks.

Last time I checked TOGA worked great.

Its function was improved with the service packs.

 

Are you sure you had the flaps not up or that you had GS capture?

Otherwise TOGA for go around is not armed.

[jgoggi 65]

 

 

Are you sure you had the flaps not up or that you had GS capture?

 

Rob, please check the video I made:

http://youtu.be/sagJjRbFlfk

 

It seems to me that I am perfectly configured for the approach, but if you find something not correct, please tell me. The very strange thing is that, after I press TOGA, the roll and pitch modes change from LOC-G/S to TOGA, but the thrust mode remains in SPD, doesn't change to THR, thus there is no increase in thrust and the airplane doesn't start climbing.

[777simmer 117]

Rob, please check the video I made:

http://youtu.be/sagJjRbFlfk

 

It seems to me that I am perfectly configured for the approach, but if you find something not correct, please tell me. The very strange thing is that, after I press TOGA, the roll and pitch modes change from LOC-G/S to TOGA, but the thrust mode remains in SPD, doesn't change to THR, thus there is no increase in thrust and the airplane doesn't start climbing.

Hmmm yes that does not look right at all.

 

Have you contacted PMDG support?

 

I have no time right now to try it....but will do so tomorrow.

Like I said, last time around it did just fine.

[jgoggi 65]

Thank you, Rob. I tried at work and I get the correct THR indication. I really can't understand what is wrong at home. Anyway I will try and delete all panel settings and all saved flights and restart with the default installation panel settings.

Thank you guys for your help.

[jgoggi 65]

I have erased all panel states, all flights, FSUIPC.ini and used the original Aircraft.cfg, but nothing works...

 

Now I am reading this on the 777 Introduction pdf file (page 0.00.53):

 

"I’m seeing erratic changing fuel loads and autopilot issues.

There is an issue with the BIOS/UEFI clock and high precision event timer on certain recent Asus motherboards at the time of this writing. The timer becomes erratic or stops completely and causes issues with the aircraft systems. We use these timing functions extensively and they must be working correctly for proper operation of the airplane. Check with Asus for a firmware update and consider replacing the CMOS battery on your motherboard if you experience these issues. The problem is not specific to PMDG or to FSX and has been widely reported on the big hardware forums around the Internet. If you are building a new PC for FSX, we recommend staying away from Asus motherboards until this issue is confirmed to be resolved."

 

I have an ASUS Z87 Plus motherboard, purchased Sep 2014. I hope the problem is not related to it, otherwise I am really in big troubles. How can I check that? Further, why should I change the CMOS battery?

[777simmer 117]

I think that particular CMOS problem caused the airplane to go absolutely crazy.

Not just fail to do certain things.

 

But I also think that problem has been solved by a specific update routine.

You should at ASUS.com

[jgoggi 65]

After a lot of testing I found out that if I do a complete flight, from takeoff to landing, the THR mode works during go around, but if I go around and then perform a second approach with a second go around, when I press the TOGA switch this second time the mode remains in SPD and the aircraft doesn't climb. I think there might be a bug here, the THR mode should work in any case. Could anyone please try a second go around? Thanks.

[Budbud 227]

Hi,

 

I have just done a flight test around KPAE, two successive go-arounds followed by a full landing. All worked perfectly and during both GA, the Auto-throttles switched to thrust mode.

I haven't tested a second GA after a first GA at Thrust Ref (twice TOGA) though. But according to what I understood, your issue doesn't depend on whether you press TOGA once or twice?

[jgoggi 65]

 

 

I haven't tested a second GA after a first GA at Thrust Ref (twice TOGA) though

 

Thank you for testing. If you press TOGA twice will you have THR REF displayed? That's another point I would like to understand, when I press TOGA the second time the mode remains in THR, not THR REF, even if the throttles correctly advance to the GA N1.

[Budbud 227]

Hi James,

 

I did two successive go arounds tonight pushing twice the TOGA buttons and it led me to a bit of confusion as I obtained two different results... I will have to to more tests to clarify this.

First, it seems for both GA that full thrust was applied by the autothrottles only after flaps retraction to flaps 20 and/or gear up... (This I must also clarify). Before any of these actions, the thrust remains to thrust.

 

Now the difference.

On the first GA, after the second push, thrust switched to Thrust Ref while getting full thrust. On the second GA, it remained to thrust...

 

I'll have to test now how the things interract between flaps, gear, and the time of the first push and the second one... I'll go to read also again a little the FCOM and FCTM because, I realize that I don't really know how it works for a GA with full thrust...

For instance, do twice pushes on TOGA be immediately one after the other, or must I wait for the second one for any action before or period of time?

[jgoggi 65]

Thank you, Romain. I think there is something not working correctly. I tried at least 15 go around and only once, like you, after retracting gear and flaps, I had THR REF, all the other times only THR and, above all, never THR REF after pressing the button twice. Maybe it's something for the developers to look into....

[Budbud 227]

You should report it by submit a ticket. It is the most effective way.

[jgoggi 65]

Already done, waiting for a feedback  ^_^