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cathay747

PMDG 777 false terrain alarm

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I'll play ignorant.  I thought yellow was close to you and red above? Don't know the specifics but I'm willing to learn.

 

Regardless, the alarms were false. Does cycle 1502r2 (current cycle) provide same results?  If so, that is reason to submit a trouble ticket.

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<p>

 

That's a pretty poor picture, to be honest. I mean, I can see most of the major things are covered - gear is down and flaps seem to be a in a landing config - but taking a picture/camera with a phone is a bit backward. The sim comes with a default screenshot button. Just hit the V key...

 

Concerns:

  • Your selected speed is below your VREF. If anything, it should be at least 5 above it.
  • Your INIT REF page isn't displayed, so I don't know what flap setting you've selected to see if it matches.
  • Based on the picture, it's hard to tell, but it seems like you have add-on scenery that isn't lining up with everything. That isn't going to cause it directly, but it could be an indicator of another problem causing it. It could just be the odd angle you have things set at.

Vref is 119 with flaps 30, the autoland worked fine and the plane did flare and land on the runway

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Vref is 119 with flaps 30, the autoland worked fine and the plane did flare and land on the runway

It would've done it right at the flap limit speed, too. That doesn't mean it's good, or right. If you're not using proper procedure in one area, I'm betting you're using improper procedure somewhere else, which could be causing this.

 

If you want a plane to behave realistically, you have to treat it realistically.

 

Your speed clearly shows below the VREF marker. We're you using the Flap 25 marker for a Flap 30 landing? I mean...the fact that you're clearly ignoring the plane here kinda tells me you're ignoring other things, too, which could be the cause of your issues.

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I'll play ignorant. I thought yellow was close to you and red above? Don't know the specifics but I'm willing to learn.

 

Regardless, the alarms were false. Does cycle 1502r2 (current cycle) provide same results? If so, that is reason to submit a trouble ticket.

Yes the warnings are false but they shouldn't be there at all. If I had 1502 I would have been flying it. Why would a false warning with 1502 be indicative of a problem but not with 1501?

 

How do you explain the elevated terrain displayed immediately around the airport? That caused the warning. Everything else was green.

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It would've done it right at the flap limit speed, too. That doesn't mean it's good, or right. If you're not using proper procedure in one area, I'm betting you're using improper procedure somewhere else, which could be causing this.

 

If you want a plane to behave realistically, you have to treat it realistically.

 

Your speed clearly shows below the VREF marker. We're you using the Flap 25 marker for a Flap 30 landing? I mean...the fact that you're clearly ignoring the plane here kinda tells me you're ignoring other things, too, which could be the cause of your issues.

I have NOT misused the plane or used it unrealistically.

 

Vref is 119 (speed on the AP panel) for flaps 30 and I am clearly in the right speed range

my speed is clearlu

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I am getting the same problem, two airports I recall is OMDB and EGLL.

 

The terrain warning kicks off at about 1000ft AGL and accompanies down till I'm about 10ft above the ground. I also have missing callouts like 500, 400 but I do get "2500" and "10" callout. I always have Flaps 30, speedbrakes armed and autobrakes at 3 on both airports. I also have VREF + 5 speed and I normally disengage AP at 1000ft. I will provide a screenshot if I can. I use AIRAC 1501.

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just heard that AIRAC cycle 1503 is released, will that solve the issue?

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An AIRAC is a navigation database.

An update would update airways, SID and STAR, so that the things you can select from your FMC are identical to the real world paper charts.

 

It does not update the terrain database.

 

FSX terrain can be updated to reflect real world terrain better with addon like FSGenesis mesh (there are other products for mesh too but I use FSGenesis).

Updating FSX mesh (terrain) is nice but will not fix your problem.

 

Because the PMDG777 terrain database (which is what gives you the warning when close to terrain) can not be updated as far as I know.

 

False terrain warnings could occur if you are descending towards an airport that the terrain database does not have.....but OMDB and EGLL will surely be in the database.....so I dont know what causes your false warning.

Maybe your PMDG777 terrain database was corrupted and needs to be restored?

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Just saw this thread.  A few points and suggestions:

 

The file WpNavApt.txt has entries for each airport runway.  It is updated as part of each new Airac.  The last 5 digits of each runway entry are the altitude for that runway.  For example KATL is 01026. 

 

The file ARPT_RWY.dat, also in the PMDG/NAVDATA folder, is NOT part of an Airac (take a look at the first line, and compare it to Airac files).  It is generated by the PMDG 777 and used, AFAIK, as a kind of cache.  It also has entries for every airport and runway.  At the end of the first line of each airport entry is an altitude number (following the last semicolon).  For each runway, the fifth field in (marked by semi-colons) is the altitude for that runway.  Here is KDEN RW 7, 5434 is the runway's altitude:

 

RW;07;39.840945;-104.726656;5434;11155;082;082;12000

 

So, would those people who are having a problem please take a look at the entries in the above two files for the problem airports to see if the altitude is incorrect?  All these files can be opened and searched w/ Notepad.  Just don't edit or save them!  This would help narrow down the issue.  Please report back.

 

Also want to mention that Airports.dat is part of the Airac, but only has longitude/latitude for each airport, no altitude data.

 

If ARPT_RWY.dat has an altitude error, please note it and then remove that file from PMDG/NAVDATA.  It will regenerate the next time you load the 777.  See if that fixes the problem and report back.  This procedure is known to fix other errors having to do w/ runways not showing up in the FMC.

 

Finally, as another clue, I have only noticed "Pull Up!" when approaching Kai Tak runway 13.  I approach on the glideslope, but when I make the turn it becomes a visual landing and I may or may not still be on the glideslope (and am definitely not on the loccalizer!).  It's after the turn as I approach the runway that I get the warning.

 

Hope this helps!

 

Mike

 

 

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Members

40 posts

Joined 5 Months and 4 Days Ago.

 

Posted 04 February 2015 - 02:53 AM

I was landing at LHR with the 777-300ER the other day, and when I was locked and coming down the glideslope, at about 1000ft, the terrain alarm screamed all the way until I touched down on 27R, despite I was in full landing configuration (flaps 30, gear down, autobrakes 1)

scenery : UK2000 London extreme

 

OK, I've been able to reproduce the problem.  I changed the altitudes for all runways at KSFO to 1013 instead of 13 in both wpnavapt.dat and ARPT_RWY.dat (altitude data as described in my previous post).  I loaded a previously saved, often used 28R approach situation using the 200LR (in Steam - @ 6 mi out), and got "Caution terrain" all the way down the GS until @ 200 ft, when I got "Terrain, Terrain!  Pull UP!" w/ appropriate indications on the DUs.  

 

I deleted the ARPT_RWY.dat file and let it rebuild.  It picked up the incorrect 1013 altitudes, presumably from WPNavApt.txt.  Same warning result.

 

I fixed the data in wPNavApt.txt, deleted ARPT_RWY.dat and allowed it to rebuild, reloaded the same 28R approach, and no more problems.

 

So the next time this happens, check the altitude entries for the problem airport in WPNavApt.txt and see if they are wrong (as I described earlier).  If not, delete ARPT_RWY.dat and allow it to rebuild.  See if that fixes the problem.

 

It's still not clear if the problem is coming from the Airac data, presumably in WPNavApt.txt, or the PMDG 777 cache file, ARPT_RWY.dat. So I hope people w/ this issue will report back on what fixes it.

 

Mike

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ok so for vhhh07L it says 12467 in my wpnavapt

what do the numbers represent? feet? Any decimal places involved??

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ok so for vhhh07L it says 12467 in my wpnavapt

what do the numbers represent? feet? Any decimal places involved??

That's runway length in feet. The figure for threshold elevation is at the very end of the line, last five digits IIRC. For VHHH it's 28 feet.

 

This data also appear in ARPT_RWY.dat. The elevation is after lat/long in that file.

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Also want to add that ARPT_RWY.dat has TWO entries for each runway, one presumably from the Airac/wpnavapt.txt file, and one apparently from FS's database.  So there could be an issue w/ either entry for a given runway, but I did not experiment w/ the runway entries that begin w "FS;".  But they both should be checked (also have to wonder if even a small discrepancy in altitude between the two runway entries causes problems).

 

Mike

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Also want to add that ARPT_RWY.dat has TWO entries for each runway, one presumably from the Airac/wpnavapt.txt file, and one apparently from FS's database. So there could be an issue w/ either entry for a given runway, but I did not experiment w/ the runway entries that begin w "FS;". But they both should be checked (also have to wonder if even a small discrepancy in altitude between the two runway entries causes problems).

 

Mike

Everyone's ARPT_RWY.dat is different. I haven't seen any FS entries in mine for example.

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Hi guys!

 

And what the solution of this problem?

 

1504 AIRCAC, the same problem...

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And what the solution of this problem?

 

Hi, Alex155,

 

Have you tried deleting ARPT_RWY.dat in fsx>PMDG>NavData  ?  You can back it up first to be on the safe side.  It will rebuild the next time you reload the 777.

 

PMDG wants everyone to use full names in its forums.

 

Mike

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Have you tried deleting ARPT_RWY.dat in fsx>PMDG>NavData  ?  You can back it up first to be on the safe side.  It will rebuild the next time you reload the 777.

 

Thank you for reply, but it doesnt help  :(  Still have "Terrain" warning on landing phase.

 

Now i am pushing "Terr ovrd" button (Near gear lever) on final, to disable this warning. But i hope to find other solution of this problem.

 

Alex

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Thank you for reply, but it doesnt help  :(  Still have "Terrain" warning on landing phase.

 

Now i am pushing "Terr ovrd" button (Near gear lever) on final, to disable this warning. But i hope to find other solution of this problem.

 

Alex

I guess that when you updated to 1504 you reintroduced the problem?

 

I think what Mike meant is that you have to go through the same procedure each time untill Navigraph puts in the proper elevation numbers in their Airac cycles.

Just saw this thread.  A few points and suggestions:

 

The file WpNavApt.txt has entries for each airport runway.  It is updated as part of each new Airac.  The last 5 digits of each runway entry are the altitude for that runway.  For example KATL is 01026. 

 

 

I did not know the 777 terrain database is updated from the Airac cycles.

Interesting and cool!

 

I wonder how terrain height is known when away from an airport though and how that terrain data can be updated to reflect FSGenesis mesh for example.

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Thank you for reply, but it doesnt help :( Still have "Terrain" warning on landing phase.

 

Hi, Alex,

 

Please name the specific airport and runway(s) where the problem is found, and please post the entries for the airport from the WPNavApt.txt and ARPT_RWY.dat files.  They are located in FSX>PMDG>Navdata.  You can open them with Notepad and won't damage them as long as you don't use "File>save" or "File>save as."  Also, any airport or other scenery near the airport.

 

Again, PMDG's moderators require that you sign your full name.

 

 

Thanks,

Mike

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So, would those people who are having a problem please take a look at the entries in the above two files for the problem airports to see if the altitude is incorrect? All these files can be opened and searched w/ Notepad. Just don't edit or save them! This would help narrow down the issue. Please report back.

 

I have this problem on OMDB (Fly Tampa) at runaway 13R aproach. So I've look into the files that you mention, but the altitude is correct in both (and so for all other 3 runaway at OMDB):

 

wpnavapt:

 

OMDB30R13123300 25.247708  55.380933110.9030000032

 

arpt_rwy.dat:

 

RW;30R;25.247708;55.380933;32;11090;300;300;13123

 

And stiil have false terrain alarm. As I mention at the begining at this topic, this issue have started after I upgrade the airac cycle to 1502. The wierd thing is that if I downgrade the airac cycle to 1408 the issue dissapear.

So I'm not so shure that the two files wich you mention are the problem. What do you think?

BTW: the numbers are identical in both files no matter wich airac cycle I use (1502 or 1408).

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I've try to look deeper into this problem. There is another add-on wich use the runaways.xml file created with "make runaways" tool form the root of FSX :RAAS. As indicated in the manual of RAAS, after you install a new scenery, to avoid incorect calls problem of runaways or maybe not playing the advisory, you have to run this tool "1. Run the MAKE RUNWAYS tool to refresh your runways database". So I open the file created by "MakeRwys" tool wich is "runaways.xml", and at the same runaway on OMDB - 30R - found this:

 

OMDB,0302,25.247707,55.380978,34,300,13143,110.90

 

As you can see here is 34 and not 32. But a very little difference, I mean we talk about 2 feet, could cause the incorect Terrain call?

 

The difference is bigger with the  30L runaway:

 

ARPT_RWY.dat (navdata folder pmdg) is:

 

RW;30L;25.235919;55.394881;60;11130;300;300;14590

 

runaways.xml (root fsx used by RAAS) is:

 

OMDB,0301,25.235296,55.396034,34,300,14606,111.30

Here we talk about 26 feet difference!

And this put on another logic question:

 

Did RAAS have something to do with the false terrain allarm? :o

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I have this problem on OMDB (Fly Tampa) at runaway 13R aproach. So I've look into the files that you mention, but the altitude is correct in both (and so for all other 3 runaway at OMDB):

wpnavapt:

 

OMDB30R13123300 25.247708 55.380933110.9030000032

 

arpt_rwy.dat:

 

RW;30R;25.247708;55.380933;32;11090;300;300;13123

 

And stiil have false terrain alarm. As I mention at the begining at this topic, this issue have started after I upgrade the airac cycle to 1502. The wierd thing is that if I downgrade the airac cycle to 1408 the issue dissapear.

 

So I'm not so shure that the two files wich you mention are the problem. What do you think?

 

BTW: the numbers are identical in both files no matter wich airac cycle I use (1502 or 1408).

 

Artur Munteanu

 

 

 

Hi, Artur,

 

Thanks for going to the trouble of posting this information!

 

I don't have any addon scenery for OMDB, so that may be an important difference. 

 

I set up an approach to 30R with my current data, which is Airac 1503.  I did get some pull up messages on my first try, but this is because the current ILS data is different than my old, default scenery ILS.  I got a little low since I was expecting a GS indication and wrongly thought I was too high :huh:.  Once I tuned the ILS to match the FSX (old) frequency, it worked fine.

 

There are two differences between the data you posted, from wpnavapt.txt, Airac 1502, and what I have (1503): in mine, the altitude is 62 instead of 32, and the runway  length is 14275 instead of 13123. 

DUBAI INTL              OMDB30R14275300 25.247708  55.380931110.9030000062

 

So I put this data into my wpnavapt.txt file, deleted ARPT_RWY.DAT, and reloaded the setup for the approach.  I also reloaded the runway approach in the FMC.  ARPT_RWY.dat did pick up the differences for that runway, both altitude and length.  But again, no issues on an ILS approach.

 

If the numbers between the two airacs are the same, that  is really puzzling.  Could the discrepancy be between the two airport positions in the airports.dat file?? 

 

I am also wondering if it has something to do with your addon scenery?  Maybe it introduces a difference in location or hilly land on the runway approach?  It's easy to disable the scenery without fully deleting it.

 

I doubt RAAS has anything to do with it, but you can try disabling it.  But I think the scenery is more likely.

 

Mike

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There are two differences between the data you posted, from wpnavapt.txt, Airac 1502, and what I have (1503): in mine, the altitude is 62 instead of 32, and the runway length is 14275 instead of 13123.

DUBAI INTL OMDB30R14275300 25.247708 55.380931110.9030000062

 

Well... I must say that there is something wrong with the airac cycle, because there is no way that on 30R/12L rwy you have that lenght! The 14275 is the lenght of the 30L/12R!!!

"Dubai Airport has two runways, 12R/30L is 4,450 m × 60 m (14,600 ft × 200 ft), 12L/30R is 4,000 m × 60 m (13,120 ft × 200 ft)." (wiki), Also you can look at all charts for Dubai Intl.

I don't know what to say, there are too many variables wich don't mach. Is true that the scenery for Fly Tampa has an expanded area, but cover most of the city of Dubay, but was only aded the photo scenery and buildings, but not the terrain moddelling. And however the airport area, is plan without buldings or hills (it's desert there and sand on Dubai :rolleyes:), so I don't think that the scenery is the problem.

 

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