c172pilot

Keeping it real....time

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Hey everyone,

My question has to do with 'real time' flying and "mirroring" a real flight. What I mean is this: Taking the real flight plan and its scheduled times and trying to mirror what they do in real time in the sim. I am well aware that the PMDG777 has its set of performance metrics and programming so getting a 'true-to-life' burn is not necessarily likely as discussed in multiple previous posts. I have found that reducing the fuel load in P3D 3.4 for PMDG777 by 9,000-11,000lbs results in the planned arrival loads of the plan. Granted, it's always a couple hundred pounds off, no biggie.

My biggest concern, however, is I was able to get my flight I am doing today, KDFW-VHHH, to be in sync with the real flight within 1-2 minutes. Attached are two screenshots taken within seconds of each other to highlight my concern and my question:

How come my P3d flight is ~20 minutes earlier than the real world equivalent while being at the same spot geographically? I use ASN in P3d 3.4 and PMDG 777 (whatever recent update included) on a windows 7 rig. PC performance is certainly not the issue. I understand that it would be near impossible for it to be exactly the same, but I find it odd with the same parameters set I am 20 minutes ahead of sked when compared to the real live flight?

Additionally, I have noticed that my clock is also off. I know this is a constant issue with P3d/FSX and I am curious how the Zulu time will be off in the CDU compared to real world ZULU (in the program). So, to reiterate, I'll pop my brakes on time and rotate after the real one has. about an hour later- I'll return to the computer and notice I am way off on arrival time.

Has anyone been able to figre out the trick to managing the P3D clock???  If I have been too vague or confusing, please let me know so I can correct it.

IMG_9213_zpsmdccrhxg.png

 

Please note my enroute time to the real one etc...

aa125%20comparison_zpsg3w6a1ck.jpg

 

Thank you,

Sumner Rabin

 

Edited by c172pilot
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The clock in FSX (and I'm guessing P3D) is loosely tied to your frame rate.  This is one reason why some use we have time-sync programs.  Usually this is noticed by those who have issues with mircosutters, but you've found it the other way around!

There are a number of good time-sync programs, both freeware and payware.  The freeware program is called FS Time Sync (you'll find it in the AVSIM Library and a few other places).  The payware version is called FS Real Time.  I have both, and the payware version has a few other benefits as one might imagine, but the freeware version should will get the job done for you.

Best wishes.

 

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Thanks so much for the info! So, I consistently get 40+Fps in good to high density settings due to some great tweaks I use from a YouTube video. I would then assume my clock would be "fast". But it's behind. So this program will ensure my flights arrive as they should? (Obviously taking into account winds etc...)

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Hi Sumner,

Could you maybe link that Youtube video you speak of? Would like to have a look at that.


Thanks!

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Hmmm,

 

it could be so many things. Especially for a long haul flight. At that distance from Hong Kong the small difference in Cost Index and actual winds aloft may skew the results considerably. The better way to verify your concern would have been to actually compare the arrival time. A comparison of the current ground speeds would also give some answers. The reason I post is that even though I have FSRealtime I see little difference between my watch and FS time when I don't use it. So I doubt it alone is responsible for the difference.

 

Regards, 

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2 hours ago, xkoote said:

The reason I post is that even though I have FSRealtime I see little difference between my watch and FS time when I don't use it.

 

It's for sure that frame rate affects time, and if could just be that you're system is running in a manner that matches up.  Mine too is pretty close, but I know those with slower systems that lag behind. The above is the first time I've seen someone who is ahead time wise.

 

Agreed regarding the difference between weather, temps, etc. 

 

 

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All on line traffic services, such as Flightaware, provide information on the track displays that are delayed, usually about 20 min. This is for a variety of reasons as you can imagine.

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FligthAware is, yes... but FlightRadar24 (which his screenshot is from) isn't.

At least where I live (Denmark) it's pretty much live - or no more delay than max 30 seconds...

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Hi Sumner,

The clock may be part of it -- but beyond that I think you also need to take in to account that, although the MSFS/P3D world is pretty good, it is not perfect.

The P3D atmosphere, for instance, is pretty good. But it is not perfectly realistic. Nor are the ASN winds and temperatures going to be absolutely identical to those experienced by the real flight. Nor does the PMDG 777, good though it is, perform quite exactly like a real 777. The P3D globe is pretty accurate, but it is not perfectly accurate (tried flying over the poles?). And so on and so forth.

Also -- and perhaps even more relevantly -- do you know how FR24 calculates ETAs? I don't, but I would not be entirely surprised if it is pretty rudimentary: i.e. take current ground speed and divide by great circle distance remaining to destination. I'm 99.9% certain that that ETA data is not directly from the real aircraft's FMS, and I'm pretty much 100% certain that it doesn't take in to account wind, weather and temperature data for the remaining distance. This could easily result in significant differences to the predictions your PMDG 777 FMS is making, which do take all of that stuff in to account and are therefore far more accurate.

When does the FR24 elapsed timer start counting? Is at at pushback or airborne time, is it automatically sensed or based on an actual OOOI report? What about your elapsed timer?

There are lots and lots of variables.

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I apprecaite all your input, fellas.I work for this particular airline and have live access into the database so I use FR24 for visual purposes only.

 

I have given it more consideration and feel that perhaps I am just too eager to make simulation- a reality.

In this flight, I landed at the same "time" the real one did (granted, I held for 10 minutes to decend, so really I was 10 minutes earlier). And, I was 7 minutes shorter on the flight time. I suppose, that's about as real as one can get.

Are there other suggestions you all may have to improve any realism performance I could use??

 

Thank you all!

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2 hours ago, skelsey said:

Hi Sumner,

The clock may be part of it -- but beyond that I think you also need to take in to account that, although the MSFS/P3D world is pretty good, it is not perfect.

The P3D atmosphere, for instance, is pretty good. But it is not perfectly realistic. Nor are the ASN winds and temperatures going to be absolutely identical to those experienced by the real flight. Nor does the PMDG 777, good though it is, perform quite exactly like a real 777. The P3D globe is pretty accurate, but it is not perfectly accurate (tried flying over the poles?). And so on and so forth.

Also -- and perhaps even more relevantly -- do you know how FR24 calculates ETAs? I don't, but I would not be entirely surprised if it is pretty rudimentary: i.e. take current ground speed and divide by great circle distance remaining to destination. I'm 99.9% certain that that ETA data is not directly from the real aircraft's FMS, and I'm pretty much 100% certain that it doesn't take in to account wind, weather and temperature data for the remaining distance. This could easily result in significant differences to the predictions your PMDG 777 FMS is making, which do take all of that stuff in to account and are therefore far more accurate.

When does the FR24 elapsed timer start counting? Is at at pushback or airborne time, is it automatically sensed or based on an actual OOOI report? What about your elapsed timer?

There are lots and lots of variables.

Thank you for that insight! I appreciate :).... The timers for FR24 must be upon radar contact. I know Flightaware is based on brake release.

14 hours ago, harvester21 said:

Hi Sumner,

Could you maybe link that Youtube video you speak of? Would like to have a look at that.


Thanks!

I will keep looking for it. I can't find it. but it's a tweak not involving opening DLL's or anything like it. it involves using the Nvidia Inspector

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My sim flying has become 100% mirroring the real routes in real time, and getting the real plans if I can. I tune into liveatc.net if the areas are covered through the entire flight. Never had this much fun, to be honest. Your Dallas to Hong Kong flight has a lot of liveatc coverage

Departure:

https://www.liveatc.net/search/?icao=kdfw

Finding en-route atc is an art but I fly and my laptop has up the liveatc coverage map to help. For Pacific coverage

https://www.liveatc.net/search/?icao=hf

san francisco radio and nat Pacific tracks are sometimes online. You can hear the real flight getting requests possibly being told to set a lower speed for traffic. VHHH liveatc can be busy in the small number of feeds but you have complete arrival, tower and ground coverage at that airport too.

The biggest thing I see to make your time different than the real thing is the Pacific ocean. Active sky does a great job but you can only do so much. sometimes you get more winds than the real flight sometimes less. I recently moved to Active sky 16 from active sky next and found more accurate data from as16.

The next problem is something you find listening to real atc and having the real plan. You get set speeds, step climbs, and make sure you are using the correct cost index that can be tough to get unless you have the real plan since most airlines today use a range all computed by their flight planning computers. And I almost forgot, you could be a lot lighter than the real flight the real loads combined with everything else helps make you mirror the real flight close to perfectly I have found. Hope this helps a bit.

 

Flying real time has made flight sim exciting again and I pick routes that have departure and arrival coverage from liveatc if I can, folloing the atc instructions as if I am there makes every flight unique. - David Lee

 

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3 hours ago, 777200lrf said:

My sim flying has become 100% mirroring the real routes in real time, and getting the real plans if I can. I tune into liveatc.net if the areas are covered through the entire flight. Never had this much fun, to be honest. Your Dallas to Hong Kong flight has a lot of liveatc coverage

Departure:

https://www.liveatc.net/search/?icao=kdfw

Finding en-route atc is an art but I fly and my laptop has up the liveatc coverage map to help. For Pacific coverage

https://www.liveatc.net/search/?icao=hf

san francisco radio and nat Pacific tracks are sometimes online. You can hear the real flight getting requests possibly being told to set a lower speed for traffic. VHHH liveatc can be busy in the small number of feeds but you have complete arrival, tower and ground coverage at that airport too.

The biggest thing I see to make your time different than the real thing is the Pacific ocean. Active sky does a great job but you can only do so much. sometimes you get more winds than the real flight sometimes less. I recently moved to Active sky 16 from active sky next and found more accurate data from as16.

The next problem is something you find listening to real atc and having the real plan. You get set speeds, step climbs, and make sure you are using the correct cost index that can be tough to get unless you have the real plan since most airlines today use a range all computed by their flight planning computers. And I almost forgot, you could be a lot lighter than the real flight the real loads combined with everything else helps make you mirror the real flight close to perfectly I have found. Hope this helps a bit.

 

Flying real time has made flight sim exciting again and I pick routes that have departure and arrival coverage from liveatc if I can, folloing the atc instructions as if I am there makes every flight unique. - David Lee

 

Hey David,

I like where your head is and what you do for realism. But, I would be lying if I said I actually sat there for more than 1 hour for the entirety of the flight LOL. For this particular flight (while it was done in real time) I went to work, hit the gym, made dinner for the wife and I, went swimming and watched a movie from appleTV and so on. I use the auto step climb and pause at TOD. THANK YOU PMDG for those features!!! I will say I am impressed by your commitment. I do love LIVEATC.net!

 

I will say I am NOT on the latest release of ASN as I kept getting CTD's, and am cautious to update to the latest release.

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On 3/8/2017 at 8:24 PM, c172pilot said:

Hey David,

I like where your head is and what you do for realism. But, I would be lying if I said I actually sat there for more than 1 hour for the entirety of the flight LOL. For this particular flight (while it was done in real time) I went to work, hit the gym, made dinner for the wife and I, went swimming and watched a movie from appleTV and so on. I use the auto step climb and pause at TOD. THANK YOU PMDG for those features!!! I will say I am impressed by your commitment. I do love LIVEATC.net!

 

I will say I am NOT on the latest release of ASN as I kept getting CTD's, and am cautious to update to the latest release.

I cheat often by being away from the controls but I do have at least one day a week I can fly 3-5 hours and once a month I can do a 10+ hour flight so I enjoy the realism of trying to simulate the entire flight - David Lee

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