Jump to content

Archived

This topic is now archived and is closed to further replies.

adamant365

Time Prediction Way Off

Recommended Posts

Hey everyone,I'm cruising along in the beautiful 737-600 (WestJet 571, CYHM to CYYC), and I just went to check my PROG page for an ETA at CYYC, and it says that I'm going to arrive at 0655Z. The problem is, the current time is 2239Z. I know it's not going to take another 8hrs, 16 mins to get there from where I am (somewhere over Lake Superior). Also, even though the current time is 2239Z, it says I will arrive at the DLH VOR at 0442Z. But DLH is only 160NM from my current location.I've checked my flightplan for any waypoints that are way off course but there are none. And yes, I've double-checked that my NGX clock is displaying zulu and not local time. The fuel prediction looks spot on based on the winds I entered and the distance/payload in that I planned for 4200 LB reserve and it is predicting arrival at CYYC with 4600.Has anyone else noticed this issue? I think this is the first I've noticed it. A lot of times when I'm flying, I check what's on the PROG page to know how long it is going to take me to get there and I don't recall such a discrepancy before. This is also the first I've flown the -600 so maybe it is A/C specific??Thanks,


Adam Hill

Share this post


Link to post
Share on other sites

I have no such issues with the 800/900 NGX models after several test flights. Unfortunately I have not yet purchased the add-on.


Craig Williams

Share this post


Link to post
Share on other sites

What time are you looking at? Your system (pc) time or the sim time. The fmc will be referencing the time in relation to the time that has been set for the sim time.


Nyasha Gwaza
FSX, DP55WB, Intel Core i5-2300 processor 2.8 Ghz, NVIDIA GeForce 9400GT graphis card, 8GB RAM, Windows 7 Professional 64 bit

 

Boeing777_Banner_Pilot.jpg

Share this post


Link to post
Share on other sites
What time are you looking at? Your system (pc) time or the sim time. The fmc will be referencing the time in relation to the time that has been set for the sim time.
I am looking at the time on the NGX clock to the left of the PFD. I always set the FSX sim time to the departure time of the real flight I'm simulating, minus about 15 minutes for cockpit prep. So, for this flight WS571, the departure time is 1625ET. So, from the free flight menu, I changed my location to CYHM gate 5, selected the 736 WS livery, and then changed the LOCAL TIME in FSX to 1610ET. FSX showed 2010Z at that point which is correct for eastern daylight time. Then I loaded up the sim, did my preflight prep, taxied, took off, and it wasn't until about an hour into my flight when I wanted to check my ETA in YYC that I noticed the big discrepancy.I never sync my Sim to PC time or anything like that...would FS Real Time alleviate an issue with time prediction in the NGX if my FSX time is not synced to real-world time??Another example...I'm coming up on GFK VOR. The NGX says I will arrive there at 0419.9Z but my current NG clock time says 2336Z and I'm only 10NM from the VOR. As soon as I passed the VOR, The ATA on the PROG page shows that I arrived at 2337Z and the "Data" on the Nav display changed to reflect the actual time I crossed it instead of the predicted 0419Z.

Adam Hill

Share this post


Link to post
Share on other sites
I am looking at the time on the NGX clock to the left of the PFD. I always set the FSX sim time to the departure time of the real flight I'm simulating, minus about 15 minutes for cockpit prep. So, for this flight WS571, the departure time is 1625ET. So, from the free flight menu, I changed my location to CYHM gate 5, selected the 736 WS livery, and then changed the LOCAL TIME in FSX to 1610ET. FSX showed 2010Z at that point which is correct for eastern daylight time. Then I loaded up the sim, did my preflight prep, taxied, took off, and it wasn't until about an hour into my flight when I wanted to check my ETA in YYC that I noticed the big discrepancy.I never sync my Sim to PC time or anything like that...would FS Real Time alleviate an issue with time prediction in the NGX if my FSX time is not synced to real-world time??Another example...I'm coming up on GFK VOR. The NGX says I will arrive there at 0419.9Z but my current NG clock time says 2336Z and I'm only 10NM from the VOR. As soon as I passed the VOR, The ATA on the PROG page shows that I arrived at 2337Z and the "Data" on the Nav display changed to reflect the actual time I crossed it instead of the predicted 0419Z.
I had similar concerns last night. It was proposed that you set the time to GMT time... I haven't tested, but there was also a suggestion of a utility that fixes FSX time issues... Hope this helps!

Buddy Morgan

 

Specs removed by Admin. See AVSIM Signature policy in Hangar Chat

Share this post


Link to post
Share on other sites

Another interesting note...from my original post, while I was out over Lake Superior, the FMC was reporting a prediction of 0655Z at CYYC. Now that I'm another hour into the flight, the FMC is reporting a prediction at CYYC of 0552Z. So there is something funny going on with the prediction logic itself. At least with this flight anyway...

I had similar concerns last night. It was proposed that you set the time to GMT time... I haven't tested, but there was also a suggestion of a utility that fixes FSX time issues... Hope this helps!
Thanks, I'm not quite sure what you mean by set the time to GMT. When I set up my flight, I'm setting the local time which also changes the GMT in the sim. As for the utilty, "FS Real Time," I may try it out. Of course, the strangeness of FSX issues dictates that I may never see this issue again.

Adam Hill

Share this post


Link to post
Share on other sites
Thanks, I'm not quite sure what you mean by set the time to GMT. When I set up my flight, I'm setting the local time which also changes the GMT in the sim. As for the utilty, "FS Real Time," I may try it out. Of course, the strangeness of FSX issues dictates that I may never see this issue again.
In the time of day screen selected at the free flight screen... When I set my local time to be accurate, Zulu time (or GMT... Greenwich Mean Time) showed 1 hour fast... So the solution was to set an accurate Zulu time, regardless of what the local time says... For instance right now it's 14:39 local/19:39Z... On FSX it would show 20:39ZAs for the crossing zones and having inaccurate arrival times, I cannot verify at this time.

Buddy Morgan

 

Specs removed by Admin. See AVSIM Signature policy in Hangar Chat

Share this post


Link to post
Share on other sites
In the time of day screen selected at the free flight screen... When I set my local time to be accurate, Zulu time (or GMT... Greenwich Mean Time) showed 1 hour fast... So the solution was to set an accurate Zulu time, regardless of what the local time says... For instance right now it's 14:39 local/19:39Z... On FSX it would show 20:39ZAs for the crossing zones and having inaccurate arrival times, I cannot verify at this time.
Thanks for the reply. I see what you are saying now...but there is a simple fix (I think) for what you are describing. The Time and Season screen defaults local time GMT offset to that of the DEFAULT FLIGHT. So, since I'm near KLEX and am in Eastern time, it was always 3 hours off of the actual offset no matter where I moved my aircraft to. So, I simply changed the default situation to be the trike at KLEX instead of Friday Harbor. I haven't had GMT offset issues since then. You may try changing the default situation to start in your time zone and see if it fixes your hour-off situation. Are you in US Mountain Time by any chance??I don't know where I read about this fix, but it worked for me.Anyway, back to the issue I'm seeing...now that I'm almost 3 hours into the flight, the ETA has moved back further to 0511Z (current NG time is 0029Z). Even though that is still quite a bit off (~3.5 hours by my estimate), it is getting closer to accurate. I will simply have to do the exact same preflight again (after I land this one of course) and see if the issue persists.

Adam Hill

Share this post


Link to post
Share on other sites

Before you push back you should set your time to the link. http://www.zulutime.net/ This way you always will always depart at the actual time of day it is at your location. Zulu is pretty much used by everyone and if your not using it I have no clue why not.So instead of using the Top Local Time Set it using the Bottom GMT Time and whatever the link above says use that.


Paul Deemer

Share this post


Link to post
Share on other sites
Thanks for the reply. I see what you are saying now...but there is a simple fix (I think) for what you are describing. The Time and Season screen defaults local time GMT offset to that of the DEFAULT FLIGHT. So, since I'm near KLEX and am in Eastern time, it was always 3 hours off of the actual offset no matter where I moved my aircraft to. So, I simply changed the default situation to be the trike at KLEX instead of Friday Harbor. I haven't had GMT offset issues since then. You may try changing the default situation to start in your time zone and see if it fixes your hour-off situation. Are you in US Mountain Time by any chance??I don't know where I read about this fix, but it worked for me.Anyway, back to the issue I'm seeing...now that I'm almost 3 hours into the flight, the ETA has moved back further to 0511Z (current NG time is 0029Z). Even though that is still quite a bit off (~3.5 hours by my estimate), it is getting closer to accurate. I will simply have to do the exact same preflight again (after I land this one of course) and see if the issue persists.
I'm CST, and I did setup the default flight to load at KOKC (CST)... The problem for me was/is that despite the local time being accurate, the Zulu time was still an hour fast... Resetting to an accurate Zulu time yields an hour earlier than the actual local time... but! The sim seems to like it a bit better :). I'd crosscheck Zulu time for inaccuracies at your free flight screen and see if there are any discrepancies between that and local.In my case, I think it may have something to do with daylight savings time.... During the summer, local time is -0500 GMT while the winters are -0600 GMT... We'll find out on Saturday!Cheers!

Buddy Morgan

 

Specs removed by Admin. See AVSIM Signature policy in Hangar Chat

Share this post


Link to post
Share on other sites
I'm CST, and I did setup the default flight to load at KOKC (CST)... The problem for me was/is that despite the local time being accurate, the Zulu time was still an hour fast... Resetting to an accurate Zulu time yields an hour earlier than the actual local time... but! The sim seems to like it a bit better :). I'd crosscheck Zulu time for inaccuracies at your free flight screen and see if there are any discrepancies between that and local.In my case, I think it may have something to do with daylight savings time.... During the summer, local time is -0500 GMT while the winters are -0600 GMT... We'll find out on Saturday!Cheers!
Gotcha. I check the offset before just about every flight to make sure it is accurate and it has always been accurate. Strange...

Adam Hill

Share this post


Link to post
Share on other sites

Everytime I set it to the Zulu time if I look at the local time it is correct. I think maybe you dont have the right time zone selected in your Windows setup or else you did not enable the auto daylight savings time option?Example. I set mine to (GMT-5:00) Eastern Time (USA & Canda) and Check the Box below that for Automatically adjust clock for Daylight Savings Time. (I'm on the East Coast)It will start doing the -5 hours again when we go back to Standard Time. But for now its only -4:00 for Daylight Savings time. But if you have that Automatic Adjust Clock for Daylight Savings Time it will always be right.FSX just uses whatever your system clock is using in windows.


Paul Deemer

Share this post


Link to post
Share on other sites

Be careful with FS Real Time if you use lots of AI aircraft. If you let it regularly update the internal FS clock automatically, it can create swarming clusters of AI aircraft off in the distance, which you may not even see - except with a map utility that shows all AI aicraft around you. This is a very old FS problem that was never addressed by the FS Real Time devs. This large-scale spawning of AI can kill your FPS and may not even know why.


Regards,
Al Jordan | KCAE

Share this post


Link to post
Share on other sites
Hey everyone,I'm cruising along in the beautiful 737-600 (WestJet 571, CYHM to CYYC), and I just went to check my PROG page for an ETA at CYYC, and it says that I'm going to arrive at 0655Z. The problem is, the current time is 2239Z. I know it's not going to take another 8hrs, 16 mins to get there from where I am (somewhere over Lake Superior). Also, even though the current time is 2239Z, it says I will arrive at the DLH VOR at 0442Z. But DLH is only 160NM from my current location.I've checked my flightplan for any waypoints that are way off course but there are none. And yes, I've double-checked that my NGX clock is displaying zulu and not local time. The fuel prediction looks spot on based on the winds I entered and the distance/payload in that I planned for 4200 LB reserve and it is predicting arrival at CYYC with 4600.Has anyone else noticed this issue? I think this is the first I've noticed it. A lot of times when I'm flying, I check what's on the PROG page to know how long it is going to take me to get there and I don't recall such a discrepancy before. This is also the first I've flown the -600 so maybe it is A/C specific??Thanks,
Did you thoroughly check the flightplan to make sure that a erroneous waypoint was not included in the plan? I have seen this happened where a waypoint with same name is used but is located on the other side of the world, thus giving you the time difference...

Santos Cedeno

Dell Studio XPS 9100 Core i7 920 2.67GHZ 12GB DDR3 RAM 8GB USB RAM W7HP-x64 ATI Radeon HD 5700 1G FSX GOLD Acceleration SP2

PMDG NGX737-600, 700, 800, 900, SP1

Share this post


Link to post
Share on other sites

  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
  • Donation Goals

    AVSIM's 2020 Fundraising Goal

    Donate to our annual general fundraising goal. This donation keeps our doors open and providing you service 24 x 7 x 365. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. We reset this goal every new year for the following year's goal.


    43%
    $10,960.00 of $25,000.00 Donate Now
×
×
  • Create New...