Capturing the Localiser?

[G7USL 117]

How soon and when should this used?I don't need an instruction on how to use it, I know already, I just wondered when the earliest time it should be executed is?

[ronzie 21]

If you are taking vectors from ATC you will be given an intercept altitude and heading typically 30 to 45 degrees and in some cases 90 degrees due to various restrictions. As the indicator starts to move you adjust your AP heading to inbound and then lock onto it (set VOR/LOC or APP depending if there is a glideslope - the procedure as you know varies with your AP.)If you are only getting vectors part way, then you will get a cleared for the approach when you reach the IAF of the approach. At that time you will be expected to navigate the published procedure on your own. There can be a few types of entries such as a DME arc, procedure turn (where you fly outbound from the IAF, do a turn, and then intercept heading for inbound), and maybe some others I can't recall right now. The intercept heading will be on the procedure plate.So the answer is, if I understand your question, is to execute it when directed by ATC or by the published IAP.http://www.faa.gov/library/manuals/aviation/is a collection you might look at, particularly the Instrument Flying Handbook and the Instrument Procedures Handbook (Chapter 5 might be the best here).

[tanker 15]

The earliest would be when you are cleared for the approach and you have the localizer (no red flag). In practice, I prefer to wait until the cdi needle begins to move, then hand fly or use the heading mode to establish the aircraft on the centerline. The reason for this is that the autopilot tends to overshoot the centerline, then overcorrect, resulting in a seies of s-turns before it settles on the flight path.Dale

[G7USL 117]

Thanks for the replies guys :-)

[ronzie 21]

This is also a goodf time to issue reminder about an FS8-9 scenery bug:By default all localizers in FS appear to have the backcourse enabled. At runways that share the same frequency at each end, it is possible to be looking at and locking to the wrong one until you are just about 2 degrees off centerline.Always check the localizer ID to insure you are looking at the correct one and only then arm LOC or APP.Using AFCAD v2.21 from the libraries here, go into your favorite airports that share the localizer frequency at each end and turn off the backcourse.