ILS Freq Question

[georgetyrrell 7]

Greetings, Can anyone clear this one up?, Yesterday on app to KDEN 17L 110.15 Course 170 by the charts, 110.15 Course 171 comes up on the FMC, A/c didnt catch the glideslope. Today app to EIDW 108.9 Course 282 by the charts I have, 111.35 Course 281 on the FMC when RWY28ILS selected. what dictates the freq of the ILS? Is it the aircraft that you're flying (airac data), the default MS freq or the freq and course listed by the charts or the add on airport? Any clarity would be appreciated. retried both approaches and both times the published chart details were the correct ones.Thanks in advanceGeorge

[jc_150 3]

Hi GeorgeI thought I would try and confirm your findings. Initially I have checked the runway data for both airports using two different sources, mainly FSNAV and Navigraph. Both show that your frequencies and runway headings are correct, and both show an ILS and a glideslope, so no backcourse problems. I cannot completely understand your terminology used, as you state that you were unable to catch the glideslope. Does that mean that the A/C captured the ILS frequency, but failed to catch the glideslope, or does it mean that you failed to capture the ILS, then of course it would not catch the gledeslope either. In my approaches I try and catch the ILS first with the glideslope above me using the LOC button then catch the glideslope when it shows solid diamond by pressing app button. The nmest phase of this would be to do a flight at the airports that you state, but I cannpot do that until tomorrow (Friday) and I will report back. If I cannot do this by Sunday I shal;l be away for a week so will apologise in advance for any late response. Please tell me what plane you were using and if I have it installed i can use same.regardsJohn Calleja

[cavaricooper 2,613]

The AFCAD for the field determines the frequency and course. Obviously it is a good idea if the AFCAD and NavData are all in sync with the latest Airac. Additionally there is a Rwy surface problem (bitumen) that sometimes manifests itself.Always a good idea (as suggested by my mate Steve Bell) to check your destination AFCAD if its the first time you are flying there.The NavData just needs to mirror the AFCAD and the AIRAC update. Fortunately, ILS' don't change very often!Best-Carl F. Avari-Cooper BAW0225http://online.vatsimindicators.net/980091/523.png| XP Pro SP3 - FSGS System Unification | 2 x APC UPS | Coolermaster Stacker 830 SE | Gigabyte P35 DS3R | e8500 @ 4gHz | Tuniq Tower 120 | EVGA 8800GT 512MB | Sony 40" Bravia XBR | Creative X-Fi Fatal1ty | Bose Companion 5 | 2 x 1 GB Corsair XMS2 | 2 x 320GB WD Caviar RAID 0 | Corsair HX620W PS | CH Products Yoke-Pedals-Throttle Quadrant | Aerosoft 747MCP-EFIS-EICAS |

[downscc 1,327]

Specifically, the ILS freq/crs info is provided to the FMS by wpNavAPT.txt file in your navdata folder. This is one of the files updated each cycle, sometimes called AIRAC updates. Navigraph obtains current AIRAC data on the market, rather than directly from the FAA NACO publisher (for the US). Once every blue moon there will be an error in the data but most often it is a problem with MSFS building an aviation simulator with a static navigation database. As already explained by Carl, the freq/crs info can be manipulated with an AFCAD editor.Hope this helps. See also: http://ops.precisionmanuals.com/wiki/NAVDATA_Data_Dictionary

[Airbrakes 0]

Or if the ILS frequency dosent match the data on the FMC you could change it. Go to the Nav Radio page in the FMC and enter 108.90/282 in the scratchpad. Press 4L LSK to place the data in the ILS reciever.

[georgetyrrell 7]

Thanks everyobe for all the replies. So, to clear, it doesnt matter what freq is contained in the FMC as long as the AFCAd for the airport I'm landing at has the correct ILS details and I am flying those and I can change the freq and course manually in the FMC and it will fly the ILS?Also is the ILS freq and course changeable using the AFCAD program by Lee Swordy?Thanks againGeorge

[downscc 1,327]

The Lee Swordy program is for FS9.There is the Airport Design Editor Version 1.22 for FSX free in the AVSIM library.To be clear again, the FMC will tune to the correct current freq 99% of the time. If the current freq is different in MSFS because it is out of date, you can either manually change the FMC to the old freq in MSFS or update MSFS with an afcad file editor. Maybe 1% of the time the data used by the FMC is wrong, which in this case you just use the correct freq by manually setting it into the FMC.

[jc_150 3]

Hi again GeorgeWith the help of the other guys I recon you will solve your problem, and maybe I don't need to fly the airports. I only have fs9 and will do them if you need me to. I am away till Sunday 10thregardsJohn Calleja

[georgetyrrell 7]

Thanks John, yeah forgot to mention its the 737-700 and FS9. Got AFCAD and had a look, I changed the freq of the ILS and course to the real world charts numbers. Unfortunately as somebody suggested to change the details in the NAVRAD section of the FMC but its not the Queen just the NG. Havent really checked it out but I'd imagine there are ways to write your own procedures, and I dont mean SIDSTARS but ILS approaches?Its funny after years of fixing and tweaking I now have a PC that needs no maintainance and I can now get around to these things, I suppose its FlightSim Evolution!!George

[downscc 1,327]

<Sure, but they are just a line or two in one of the sections for the sidstars. For example, here is KDEN ILS 17L:APPROACH ILS17L FIX IRINE 7000 RNW 17LTRK 170 UNTIL 5900 HDG 120 INTERCEPT RADIAL 078 FROM FIX FQFHOLD AT FIX LIMEX RIGHT TURN INBOUNDCOURSE 078 ALT 10000 LEGTIME 1 TRANSITION GWENS FIX GWENS AT OR ABOVE 9000 FIX BXP82 AT OR ABOVE 8000First line is the approach from the FAF to the runway.Next lines are the missed approach procedure.The transitions that lead from IAF to FAF follow that.There are some fix definitions earlier in the file, but nowhere do you actually "design" the approach. Just the fixes and the route. Nothing in the PMDG simulation or the sidstar/navdata "creates" the ILS, just keeps track of what the location, freq and course so it can be used.Design the approach with the afcad editor. You position the localizer, glideslop, dme, freqs and courses and angle. There are some limits, such as the marker beacons aren't in the afcad and you can'd delete an ILS (only move it). Have fun!