Recently, I had a chance to compare the performance of PMDG's 744 to a real world flight. One of the forum members is a 744 FO for Air New Zealand and gave us a complete data-set from a flight he operated from London to Los Angeles. My goal was to precisely duplicate this flight in FS9 with the PMDG 744. It was suggested that the FSX devs might be interested in the level of realism the latest generation of 3rd party, add-on airplanes have now made available. The conclusion was that the Level of Detail these add-ons provide is not completely usable within the FS9 environment. This suggests that the FSX team has an opportunity to take advantage of the realism these airplanes provide. FSX's effort to provide reality based levels of detail in both weather and flight planning would not be wasted. The sim-planes that can take advantage of this LOD are here . . . now. Here

Hi Sam,Interesting post! Can you point me to any public web sites that have winds aloft data at 1000 foot intervals?Hope this helps,Jimhttp://www.hifisim.com/Active Sky V6 Development Team Active Sky V6 Proud SupporterHiFi Beta TeamRadar Contact Supporter: http://www.jdtllc.com/AirSource Member: http://www.air-source.us/FSEconomy Member:http://dot.kelder.net:8080/fseconomy/

Haha besides intercepting the signal from the radiosonde I doubt that would happen.Thanks Jim for all the work with Active Sky!

I'll keep my eyes open, but I've never seen a public site with that level of detail available. Actually, AS6 can still be a very valid source. The trick would be to print out the weather log, then enter these winds aloft data directly into the FMC, manually . . . but, As you might have been expecting, here's a request. Is there a way for AS6 to directly interface the FMC? In the RW, the latest (since the mid 90s that is) method of updating winds/temp data is through an enhanced ACARS satcom data link. We press "REQ WX" and the latest winds data is downloaded. We look it over and accept it. I see the interface is working between AS6 and FSBuild. But even as it is, this stuff is just amazing. Now, it's only a matter of increasing the level of detail.

Hi Sam,I asked just to be sure, but the reason is that there are some standard measuring guidelines that weather stations follow and this happens to be one of them, the altitudes that winds are measured. Yes, there may be some scientific group measuring winds every ???? feet and posting their data somewhere. But this is not world wide or even country wide.As for your suggestion: please drop a line to [email protected] and make this suggestion. It is a valid idea and would save a bunch of time in the future. We are currently working on future products and plans are not formal yet! Hope this helps,Jimhttp://www.hifisim.com/Active Sky V6 Development Team Active Sky V6 Proud SupporterHiFi Beta TeamRadar Contact Supporter: http://www.jdtllc.com/AirSource Member: http://www.air-source.us/FSEconomy Member:http://dot.kelder.net:8080/fseconomy/

How can you say it's the best fuel calculator there is based on a single data point?Even if it's not sheer luck (I doubt it is sheer luck that it's close, but a perfect match would be) you don't have enough data to make even the claim that it's dead on at all times, let alone that it's more accurate than anything else out there.

It's interesting to observe we are just comparing computer programs here. Here's the deal. The FMC (in the real airplane) calculates, then projects fuel on the basis of the environment it is (or will be) encountering. The Fuel Quantity System (in the real airplane) measures the amount of gas in the tank at any given moment. To start things off, the FMC is told how much fuel is onboard. The fuel qty sys actually measures the amount of fuel onboard. Ready? We're all fueled up and ready to go. On your mark, get set, "Gentlemen, start your engines." The FMC starts ticking down fuel on the basis of nothing but it's little computer brain. It looks at winds and altitudes and all sorts of stuff. On the basis of this information, it provides a current fuel estimate and a fuel projection for the destination -- and pretty much anywhere else along the track--. The fuel quaintly system starts ticking down fuel on the basis of the volume actually in the tank. If the FMC's "calculated" and the actual fuel quantity get too far out of whack, a boxing glove comes out of the MCP and pops the FO a good one. Now, at the end of the line, if the FMC's fuel projection matches the actual fuel quantity remaining, that means the FMC was able to accurately calculate fuel burn independently. It did NOT have to look at the actual fuel in the tank. It used nothing but it's computer program to do this.Now, I have a computer. It can be programmed. Why can't my PC be programmed to output a number based on variable (or fixed) environmental conditions just like that real 744's FMC -- a totally antique x86 based mini-box, BTW --. NO reason at all. As it appears, I have a very accurate rendition of the program loaded into a real 744 FMC on my computer's hard drive. As you suggested, this could have been a fluke, but those odds are even longer than the odds favoring that the PMDG's FMC was "dead-on." However, your point is well taken and I too think we need more testing! . . . so . . . Now that I have a definable baseline for comparison between the PMDG 744 and the real airplane (i.e., I now know it's at least in the ball park), I can now begin to make other comparisons. I'm accumulating a pretty good library of previously flown, fully noted (winds/temps/times/etc) 741/2 flight plans. These are all Pratt airplanes. As previous, (other than for the pure entertainment factor) there can be no "proof" provided by actual test flights. It'll be simply a matter of loading up the PMDG 744's FMC and checking the burn. These are different airframe and engine configurations so no direct comparison is reasonable. However, a very direct relativity should be apparent. We'll see. I'm collecting pre-flown MD11 plans too. Getting ready.

You can't compare 742 fuel consumption with 744 fuel consumption even if they use the same brand engines, same weight, and same flight profile through identical weather.The aerodynamics of the aircraft are quite different, if they weren't most airlines wouldn't have bought 744s to replace relatively new 742s. A main selling point was the lower fuel consumption of the 744...

Sure I can. The whole point of the drill was to check out this difference.