Trying to figure out the proper A/P procedure when I'm doing an ILS approach.   The ILS typically has at least two waypoints that bring you first onto the localizer then to glideslope capture.   Assuming I get vectors to final, should I then put the autopilot back in NAV / VNAV mode or simply arm LOC and after capture, ensure I'm on a good decent profile using V/S to capture glideslope. 

Any advice from RL pilots (especially airliner crew) is much appreciated. 

 

1 hour ago, 11bee said:

Trying to figure out the proper A/P procedure when I'm doing an ILS approach.   The ILS typically has at least two waypoints that bring you first onto the localizer then to glideslope capture.   Assuming I get vectors to final, should I then put the autopilot back in NAV / VNAV mode or simply arm LOC and after capture, ensure I'm on a good decent profile using V/S to capture glideslope. 

Any advice from RL pilots (especially airliner crew) is much appreciated. 

 

When on HDG to intercept an ILS, if no descent steps are needed to reach the FAF, you can activate APP mode. 

If descent steps are required, start by engaging LOC and follow crossing restrictions using VS or VNAV. Once you pass the last waypoint with an altitude restriction before the FAF, switch to APP mode and confirm the correct altitude at the FAF.

Happy landings.

8 hours ago, 11bee said:

Trying to figure out the proper A/P procedure when I'm doing an ILS approach.   The ILS typically has at least two waypoints that bring you first onto the localizer then to glideslope capture.   Assuming I get vectors to final, should I then put the autopilot back in NAV / VNAV mode or simply arm LOC and after capture, ensure I'm on a good decent profile using V/S to capture glideslope. 

Any advice from RL pilots (especially airliner crew) is much appreciated. 

 

Normally you'll be put on a intercept heading and below the glidepath, so no need to engage any other modes. Once you're on a intercept heading just arm APP mode and it'll capture localiser and then descend on the glidepath. If you're intercepting the glidepath from above you'll need to do some V/S trickery to try and establish it, but this is messy and most pilots wouldn't favour this.

3 hours ago, Tom Wright said:

so no need to engage any other modes. Once you're on a intercept heading just arm APP mode and it'll capture localiser and then descend on the glidepath. 

That is correct "only" if there are no waypoints with intermediate altitudes before FAF that include stepdowns. He needs to be aware of those restrictions. It's not just "Once you're on a intercept heading just arm APP mode and it'll capture localiser and then descend on the glidepath.    " 

Important thing that IRL you are not interjecting ILS on your own you are guided my ATC which usually brings you to heading to intercept localizer until you get GS. At this point you should have already  dialed ILS frequency, indent it - If you fly GPS you would switch to LOC mode.

if you fly antique airplane with CDI needles only. Usually ATC vectors you to intercept below GS. Important step in ILS approach is check GS intercept altitude to make sure you are not following "ghost" signal. You would use DME or cross radial to identify important fixes along localizer. We also used to use timer on approach which would be last resort to identify missed approach if everything fails 

Nowdays all ILS approaches coupled with GPS RNAV overlay so you have redundant way to identify all fixes along the way. Due nature of some busy big airports you can be cleared to ILS way out, following "feeder" routes speed and altitude restrictions. You would still need to go for LOC at FAF to ride the beams.

4 hours ago, sd_flyer said:

Important thing that IRL you are not interjecting ILS on your own you are guided my ATC which usually brings you to heading to intercept localizer until you get GS.

Just another real-life scenario. There are non-radar places or closed towers where you can be cleared for "an approach" and follow a prescribed procedure or transition. It can be any approach type of your choice based on certification. 

 

1 minute ago, LRBS said:

Just another real-life scenario. There are non-radar places or closed towers where you can be cleared for "an approach" and follow a prescribed procedure or transition. It can be any approach type of your choice based on certification. 

 

I must say there no greater load on the pilot as shooting approach single pilot without automation at night at IMC. Hail to “freight dogs” who is doing night freight in old beat up airplanes 

4 hours ago, LRBS said:

Just another real-life scenario. There are non-radar places or closed towers where you can be cleared for "an approach" and follow a prescribed procedure or transition. It can be any approach type of your choice based on certification.

Yep, I've done plenty of these when hoping around Africa, South America and into austere island destinations. They clear you to the IAF and off you go. Really fun when it's an NDB in the weather. Was really fun flying heavies and doing NDB approaches while making those "The tail will rise and the head will fall" comments. Now days with proper avionics, you fly it all by FMS with the ADF dialed up. Ya got to love it.