weird airspeed issue

[windshearDK 52]

I have now seen this happen only twice, but they are flights apart, so they both happened within proximity of one another.

 

Nothing is wrong during climb or descent, but during cruise, the green speed acceleration indicator is moving up and down, up and down, making the plane loose altitude and climb then descend, in total madness!

 

I have been flying with out such issues for quite some time now, so I do not identify anything wrong on my part, setup wise.

 

Also I noticed during ADIRU alignment, I had to reenter the coordinates after it suddenly needed the digits again.

 

Please any ideas on what is happening to my new baby?

 

Plus on my backup PFD sometimes it flashes black and it says: "WAIT ATT"?!?!

[scandinavian13 5,192]

 

 

Please any ideas on what is happening to my new baby?

 

Common problem, and about a billion threads here in the forum about it.

 

If you're using ActiveSky, or similar, use DWC mode to smooth the winds.  If you're using another weather program, crack open the manual to look at the different depiction modes they offer.  If you're using FSX default stuff, you need to either not use it, or buy FSUIPC and enable wind smoothing.

[windshearDK 52]

I use AS2012, but I tried quitting it and clearing all weather, but the problem stayed even with no wind.

 

I am a very experienced simmer, and I have witnessed previous issues with activesky with the 747X, and this seems not to be as a result of this program.

 

I have flown the NGX since it came out with out anything like this... Why is the backup PFD showing: "WAIT ATT" ? 

 

I have FSUIPC payed and installed, so I will of course check up on that program to make sure it smooths out the winds

[FLEX1978 373]

ATT means you have a problem with the air data (ADIRU) source feeding your ISFD.

 

I'll have a look for the exact msg.

 

EDIT - give this a try, push the ATT reset switch, hold for at least 2 seconds, reset takes approximately 10 seconds

 

WAIT ATT (Amber) - Indicates temporary self correcting loss of attitude.

[windshearDK 52]

I did have issues with my ADIRU alignment before the flight... Where is this ATT reset button? Any other info on what could cause this fault?

[FLEX1978 373]

ATT reset is at the bottom left of your ISFD. I had a look through the maintenance manual but couldn't find anything, also nothing in the QRH.

 

WAIT ATT is the result of your problem, not the cause. Your problem is definitely with the ADIRU and likely an issue with the align during preflight.

 

I don't own the PMDG 777 so not sure what it is says in your docs regarding the ISFD. My FCOM ref is 10.10.44 you can check your docs and see if it matches.

 

Regards

[777simmer 117]

 Also I noticed during ADIRU alignment, I had to reenter the coordinates after it suddenly needed the digits again.

 

During allignment?

Make sure you dont move the aircraft during allignment cause then it starts all over.

 

During taxi the ADIRU sometimes auto re-aligns if you stop long enough.

No need to put in new coordinates then, just ignore that, it is normal.

[windshearDK 52]

Yes at the gate alignment was started, then I went back to the init ref page and the coordinates were all boxes again, so I had to dial in my position, and the counter restarted, was a strange thing.

 

I am not moving my plane, again please remember, I am an experienced simmer and I have flown this 777 for over a 100 hours already with thousands in the NGX...

ATT reset is at the bottom left of your ISFD. I had a look through the maintenance manual but couldn't find anything, also nothing in the QRH.

WAIT ATT is the result of your problem, not the cause. Your problem is definitely with the ADIRU and likely an issue with the align during preflight.

I don't own the PMDG 777 so not sure what it is says in your docs regarding the ISFD. My FCOM ref is 10.10.44 you can check your docs and see if it matches.

Regards

 

I think there is some issue. I did have an issue aligning the ADIRU, and I think the source of the problem is to be found there. I used a saved cockpit after an uneventful flight, but I did have an issue I described in the post above... Any thoughts? Bad panel state save?? 

 

After second alignment everything looked fine! All the way up to TOC there was no problem at all

[777simmer 117]

Do the boxes also come with an FMC message?

Like "enter Inertial Position"?

 

If all power is removed from the ADIRU AFTER it has been alligned (which should not be possible because it should stay powered by the HOT Battery Bus, but could be modelled incorrectly) then that could also be a cause of having to reallign.

Or if you turn the ADIRU switch off for more than a few seconds, then you must also reallign.

 

If the ADIRU is alligned then your PFD and ND change from black to normal colours.

As long as they stay normal and you dont get an FMC message you do not have to enter a new position.

[windshearDK 52]

I know all of the above, please I am not a beginner!

I am doing my preflight CDU setup and then when I press the INIT REF page it shows the boxes.

 

I don't remember any EICAS message, but I dial in the coordinates again. No power has been lost and of course I wouldn't shut off the ADIRU during the alignment process

[FLEX1978 373]

Ok Boaz,

 

Let's both do some work that involves reading the documentation I'm going to find out exactly where the ISFD gets it data from.

 

Can you answer a question, I had a look at a screenshot of the PMDG 777 and the Standby PFD as you call it does not look like the ISFD installed on the Qatar 777 freighters, I only have access to to real world documentation so don't want to waste time investigating for you, Can you confirm you actually have an ISFD installed on your addon?

 

Cheers

[windshearDK 52]

I am using the Emirates paint scheme with PMDG setup which means only one backup instrument... I can supply a screen shot if you want?

 

And sorry for my lack of proper naming, it's just, well I fly the darn thing I don't talk to the instruments 

[777simmer 117]

I know all of the above, please I am not a beginner!

I am doing my preflight CDU setup and then when I press the INIT REF page it shows the boxes.

 

I don't remember any EICAS message, but I dial in the coordinates again. No power has been lost and of course I wouldn't shut off the ADIRU during the alignment process

I am not saying you are a beginner, I am just ticking off things from my list that could cause what you are seeing. I can stop doing that ofcourse if it annoys you.

[windshearDK 52]

I know you are trying to help, but I am letting you know that your list starts with causes that are way too simple!

[777simmer 117]

I know you are trying to help, but I am letting you know that your list starts with causes that are way too simple!

Very often the solution to a problem is actually quite simple :-)

Ok. What happens if you dont put anything into the boxes?

Is everything still ok, position correct, PFD and ND displaying properly?

(I would try an allignment myself but I am abroad so cant)

 

If so, then maybe the boxes appearing are a bug and you should report it to PMDG.