Real pilot question - What is a "Converging" ILS

[Chris Catalano 0]

Anyone know what a "Converging ILS" is and how does it differ from a regular ILS? I have charts for both kinds at KDFW in Dallas. I am not sure how to read the converging ILS charts as opposed to the regular ILS charts (which I DO know how to read). Is there any difference between the two? When I choose RWY 36 to land at on my FMC, I do not get the option to choose left or right - it only gives me "36" as a choice, yet, if I choose 36 and dial in the correct frequency for 36L, I still get my localizer & glideslope needles to work correctly. The wierd thing is that when I choose 36 from my FMC, it shows an icon for 36R with a white dashed line, yet, as I said, my localizer & GS needles work correctly if I set my radio frequencies for 36L. All very confusing for me! Why do I not get the option to choose either Left or Right in the FMC for RWY 36, and when I DO choose 36, why does the white dashed runway line that appears correspond to 36 right?Thanks all.Chris Catalano

[Guest hlm65]

Hi Chris,for what I know a converging ILS is a procedure in which SIMULTANEOUSLY two flow of aircrafts are allowed to approach two converging and ILS-equipped runways. I don't have the KDFW plates at hand, but if I remember correctly, the converging ILS should be with, for example, the 36 runways and the 31 runways or the 18s and the 13s. In both the approach plates (at least, the Jeppesen that I used) there is a caption with something as "converging simultaneous approach with rwy XX authorized". The weather minima are normally HIGHER than in normal or parallel operations.Hope this helps clarify your question regarding the converging approaches.

[Chris Catalano 0]

Thanks for the info!Two questions:a) do you read the converging ILS charts the same way as you do the ordinary non-converging ILS plates?b)How did I get the info to show correctly on my instrument panel the other night? This was despite the fact that the only choice I had in the FMC was "36" (and not 2 choices - 36L and 36R). When I selected 36 & I dialed in the freqency for 36L, it showed me a white dshed line for 36R on my instrument panel, yet all my needles worled correctly and gioded me to 36L

[Guest mseyfang]

Converging ILS approaches allow two ILS equipped runways to be used in IMC but are modified to allow to provide a greater safety margin for aircraft that are on converging courses. Generally, a converging ILS approach is the same as a regular ILS with the exception of the missed approach procedure and minima, which are higher in order to provide a higher safety margin for aircraft on converging paths in the event two planes have to execute simultaneous missed approaches. You read the charts the same. You will generally only find these types of approaches at high traffic airports like DFW and IAD. As an example, there is a published Converging ILS procedure at PIT for runways 28R and 32. The normal missed approach procedure for each runway is a hold at the EWC VOR. On the converging ILS procedure, 28R gets the missed approach hold at EWC, while the Converging ILS for 32 calls for a hold at AGC rather than EWC. Minima for each approach are raised from the standard 200' RA to 822' RA.As for the glitch in (:(, it sounds like a bug in your AIRAC database.Hope this helps.Matt

[Guest hlm65]

Hi.For question a): yes, you read the same way, the converging ILS plates are virtually the same as the normal ones except for higher minima and different missed approaches.For question :(: I don't know, seems to be a bug in your nav data files. Try to download from navdata.at a new set.Hope this helps.