MD-82 3 Posted October 1, 2013 Share Posted October 1, 2013 Hello all, after some repeated long range flights I am starting to notice that the PMDG 777 is more fuel efficient than the PFPX template for the 777. On flights of 7 hours or more, the difference can be as much as 2 tons extra on board when landing. So on my present flight I decided to validate the figures in PFPX and came to about 98% instead of the default 104% value. Now I have no trouble adjusting them. It is just that I want to know what I need to adjust. Either the PFPX BIAS or the fuel flow scalar on the PMDG 777. So my question is, in PFPX, what is the 100% bias reflect? Are the figures taken directly from FCOM's? If that is the case I will adjust the scalar of the PMDG 777. Cheers, Xander Link to comment Share on other sites More sharing options...
phil747fan 52 Posted October 2, 2013 Share Posted October 2, 2013 Xander, the datas used to create the PFPX template are the real one but i dont know which ones they use at PMDG. the datas are not coming from FCOM but from other tools more detailled. hope it helps you. the bias should be 100% unless you find a disperancy like the one found. all the best. Phil Link to comment Share on other sites More sharing options...
MD-82 3 Posted October 2, 2013 Author Share Posted October 2, 2013 Thanks Phil, made a small percentage correction in the aircraft.cfg to see how it goes. Cheers, Xander Link to comment Share on other sites More sharing options...
andyleigh 0 Posted October 4, 2013 Share Posted October 4, 2013 Hi MD82 If I was you I would stick with PMDG cfg.file. The guys at PMDG are very good at what they do. They test there configs very well. Altering it could have effects elsewhere. Better to change the bias In PFPX that's what it's there for. In the real world no two aircraft perform exactly the same the bias setting in PFPX is as real world. It's used to unjust the performance to match the aircraft. Actually there is a tool in PFPX to help you fine time the bias I can't remember what it's called. Link to comment Share on other sites More sharing options...
andyleigh 0 Posted October 4, 2013 Share Posted October 4, 2013 Looked it up. It's called the BIAS evaluator. Quote from the PFPX manual Evaluate: The Evaluate dialog allows to quickly determine Bias and Drag values for a specific aircraft type by comparing PFPX values with in-flight readings of a specific Flight Simulator add- on. An in-flight data reading should be done at optimum alti- tude and common speed schedule/cost index of the airplane desired. Enter the airplanes gross weight, altitude, present speed schedule, fuel flow per hour (total of all operating en- gines), Static Air Temperature (SAT), True Air Speed (TAS) and Ground Speed (GS). PFPX will propose a Bias and a Drag value. Use the Apply button to accept these values. Link to comment Share on other sites More sharing options...
MD-82 3 Posted October 4, 2013 Author Share Posted October 4, 2013 Thanks Andy, yes. If you see from the first post I evaluated a flight and it confirmed my suspicion that the PMDG 777 was running at 98% of the PFPX 777 calculated. And PFPX is based on actual cost index. I know that PMDG is good, but it's still FSX and it's still a simple flow scalar no matter how complex PMDG model their planes. The PFPX people have it much much more easy in that they don't have to compromise or simulate anything. They just make very complex database very user friendly. I respect PMDG for doing what they do. But for personal reason I still beleive it better to adjust the scalar just a tad to match PFPX's 777 performance tables. If I'm not happy I have retained the original value behind double slashes in the .cfg file. I can always go back to original. Thanks for the input. Cheers, Xander Link to comment Share on other sites More sharing options...
simbio 0 Posted December 27, 2013 Share Posted December 27, 2013 On a Flight from EDDP-LEBL/LERS PFPX planned 37622 lbs Fuel with a ZFW:547,000 lbs I land with 1,548 lbs I haven't change any value like BIAS or Cost index . There is a lot of discrepancy by the original poster as I should have landed with 11815LBS of fuel. What I doing wrong. Thank's Fabrizio Link to comment Share on other sites More sharing options...
Mr.Eurocup 2 Posted December 28, 2013 Share Posted December 28, 2013 these are my current! settings, Climb BIAS 96.2% , Cruise BIAS 96.2% , Descent BIAS 200.0% Drag 100.5% works perfect with my Companys Cost Index of 170 Link to comment Share on other sites More sharing options...
Emi 5161 Posted December 29, 2013 Share Posted December 29, 2013 Are these for the passenger or the freighter version? Link to comment Share on other sites More sharing options...
Mr.Eurocup 2 Posted March 19, 2014 Share Posted March 19, 2014 Are these for the passenger or the freighter version? freighter Link to comment Share on other sites More sharing options...
Pierre95 14 Posted March 19, 2014 Share Posted March 19, 2014 I use default settings and works like a charm with very good accuracy. Pierre Link to comment Share on other sites More sharing options...
Cmakris 18 Posted March 20, 2014 Share Posted March 20, 2014 I have observed it as well that with the default PFPX profile and ASN on flights of 7+ hours the fuel is approximately +2 to 2.5 tones difference. I tried to uses the Evaluate for the bias and when used the value that was calculated, I believe 98% on the next flight I ended -2 tones on the 777 than what it was predicted. I have not modified the bias to 100% and will test on the next flight. Chris Link to comment Share on other sites More sharing options...
Pierre95 14 Posted March 20, 2014 Share Posted March 20, 2014 Hi, I only fly lon range with 777 (12-15 hours) I'm always between +0.4 and +2.0 when landing. I use wind data in the FMC of course.... Cheers Pierre Link to comment Share on other sites More sharing options...
srcooke 422 Posted March 20, 2014 Share Posted March 20, 2014 Chris, There appear to be new templates for some aircraft, I guess introduced with 1.14. The PMDG 777 figures have 104% for CLB/CRZ/DES Link to comment Share on other sites More sharing options...
ITMan 7 Posted March 20, 2014 Share Posted March 20, 2014 My fuel on destination was always constant about 18000pound most of the time 100% for me CI 45 Make sure to input your cost index when creating flightplan Link to comment Share on other sites More sharing options...
Cmakris 18 Posted March 20, 2014 Share Posted March 20, 2014 Stephen, All my flights were with 1.12 and the 777LR was there with 104% and that gave me the +2 tones.I will look the templates for 1.14. Link to comment Share on other sites More sharing options...
srcooke 422 Posted March 20, 2014 Share Posted March 20, 2014 Stephen, All my flights were with 1.12 and the 777LR was there with 104% and that gave me the +2 tones.I will look the templates for 1.14. OK, I updated my fleet entries for the 747 and 777 as they were definitely different to the existing entries, which hadn't been modified. Link to comment Share on other sites More sharing options...
Cmakris 18 Posted March 20, 2014 Share Posted March 20, 2014 I have checked on 1.14. Templates for PMDG are with 104%. However if I choose the LR from the aircraft list it gives 100%. I will make a flight with 100% to check what the fuel values are. Chris Link to comment Share on other sites More sharing options...
Pierre95 14 Posted March 20, 2014 Share Posted March 20, 2014 My fuel on destination was always constant about 18000pound most of the time 100% for me CI 45 Make sure to input your cost index when creating flightplan And Make sure to set the FMC accordingly. Pierre Link to comment Share on other sites More sharing options...
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