FSX Airport Headings off?

[Mace 1,902]

>What you are seeing is a discrepancy between the surveyed>aviation databases (FAA/ Jeppsen/ DIFAF) and the satellite>photo/ real world.>I know that, but what I am asking is this question: How accurate IS GoogleEarth considered to be? Accurate to 100m? Accurate to 10m? 1m?RhettAMD 3700+ (@2310 mhz), eVGA 7800GT 256 (Guru3D 93.71), ASUS A8N-E, PC Power 510 SLI, 2 GB Corsair XMS 2.5-3-3-8 (1T), WD 250 gig 7200 rpm SATA2, CoolerMaster Praetorian case

[RFields5421 1]

Google Earth projects the photograph of KASE with the same accuracy as the base aviation data about the runway. What GE is showing is a discrepancy between the visual and the database at the same resolution and projection accuracy.There is a long discussion on GE's accuracy on Wikipediahttp://en.wikipedia.org/wiki/Google_EarthAnother issue is that GE uses the WGS-84 World Geodetic System - probably because that is what GPS satellites and technology use.That system is about 100M off the real world at Greenwich UK for the Prime Meridian.

[scott967 62]

I've never seen any horizontal accuracy statements for GE. Check this out for KEIK / 48V 40.01 -105.05 (blue outline is from USFIF data):http://forums.avsim.net/user_files/168451.jpgscott s..

[scott967 62]

You're right about KASE. I did an overlay of the GE picture and the usgs DOQQ (with transparency), also adding the USFIF data and the runway threshold positions (horizontal accuracy 5 cm) from the ngs.http://forums.avsim.net/user_files/168458.jpgscott s..

[cklink 0]

Grabbed them - Thanks Jim."One of the problems with Canada is when FSX moved the Airport scenery by about 2-3M for proper scaling the Localizers moved also." It's odd then that 26R is the only one at CYVR. Coming the other way on 08L its fine, as with the rest of the runways. They just missed that one?Looking up terminal/approach charts/freqencies etc is expected for venturing off to unknown destinations, but slewing there to verify localizer/glidescope alignment sure isn't. I have only found a few as mentioned, but it sure gives an unwanted "surprize" ending to a two hour flight in the soup.Anyways I really appreciate that you guys can (and have) fixed some of this up. It will be most appreciated once some of the commercial payear birds come over, thus doing more IRF flying in FSX vs FS9. LOL, I can just picture the LVLD767 with "autoland" on, flaring with a gental touchdown - then smashing head on into the 26R localizer building it was lined up with (100+ yards right of the runway. ;) Ooops ...Garett

[RFields5421 1]

I completed a new CYRV airfield data file for the runway heading and number change. Added a few parking spots. I've also finished a modified airport background polygon and exclude file.Anyone want to test them - send me a PM. Pretty small files - only a few KB.

[fisheye 3]

I just finished an ILS approach to MMAA Acapulco Rwy. 28 and found that the ILS was not properly aligned with the runway. It brought me in about 100 ft. to the right at touchdown but on roll out I ended up at the centerline of the runway at the opposite end. How do I fix this problem. I have tried three different programs to no avail. Whats up with FSX and after reading the posts here it looks like a larger problem than I realized. The programs I tried was AFCAD, ADE, and Microsoft SDK which might do it but I don't know how.Norm

[ryanbatc 12,816]

I've noticed this too, Duluth, KDLH, the 27 ILS freq is 108.70 course 270, as per the NACO plates dated most current.In FSX the course is 271 yet it does not match up well with the centerline. Hmmmm

[Guest sstobbe]

I am currently correcting most if not all of the BC land and water aerodromes north of Squamish and east of the Columbia River to be located and oriented correctly vs. aerial photography. I am correcting aerodrome elevations and flattens to make as accurate as possible. I am adding all listed water aerdromes in the area as well. I plan on releasing Coast Mountains first, Rockies/Columbia Mtns second, and Intermontane Plateau/Northern BC third.I use Tileproxy, and got tired of the misalignment.

[AlaskanFlyboy 7]

>I've noticed this too, Duluth, KDLH, the 27 ILS freq is>108.70 course 270, as per the NACO plates dated most current.>>In FSX the course is 271 yet it does not match up well with>the centerline. Hmmmm>>This could be due to the real-world equipment itself. Not all are perfectly aligned with the runway center-line. The goal is to bring you down near target until minimums and then from there you land visually and ignore whatever the instruments tell you. If this is a CATIII approach though, then yes, there's some issues. Felts Field has one that brings you in at an angle to keep from hitting the surrounding hills. When you see the runway, you just simply break off to the right and align yourself visually.----------------------------------------------------------------John MorganReal World: KGEG, UND Aerospace Spokane Satellite, Private ASEL 141.2 hrs, 314 landings, 46 inst. apprs.Virtual: MSFS 2004, MIDCON P-401"There is a feeling about an airport that no other piece of ground can have. No matter what the name of the country on whose land it lies, an airport is a place you can see and touch that leads to a reality that can only be thought and felt." - The Bridge Across Forever: A Love Story by Richard Bach

[scott967 62]

>I've noticed this too, Duluth, KDLH, the 27 ILS freq is>108.70 course 270, as per the NACO plates dated most current.>>In FSX the course is 271 yet it does not match up well with>the centerline. Hmmmm>>According to FAA Flight Inspection, the Rwy 27 true heading is 272.28 and so is the localizer, I-JUD.According to ADE 1.22 looking at the default data, the runway is 272.3 as is the localizer.Using Google Earth image in ADE, it appears that both runway and localizer are properly positioned.I note that FAA is using MagDec Epoch 1985 with a variation of 2E, thus the magnetic centerline would be 272.3-2 = 270 (rounded to the nearest whole degree) for the charted heading. But in FSX I get the magdec as W1.1 according to AFSD, thus you would have to fly 273.4 magnetic to track the localizer. Note that localizers don't "know" about headings; they only show a centerline based on the physical position of the antenna array, which results in an identical signal depth of modulation from each side when the ILS radio receiver is on the centerline. I understand that FSX uses MagDec epoch 2005 for its internal variation model. According to this calculator, the actual magdec for today is West 0.22 degrees, and it appears to me that the model is off a bit in FSX.http://www.ngdc.noaa.gov/geomagmodels/struts/calcDeclinationscott s..