I’m getting increasingly frustrated trying to land the 320 using ILS and the LS. I’ve watched a number of youtube instruction videos and think I’m doing everything right - and, indeed, I take off, cruise along on AP, passing all of the waypoints etc, go up and down in altitude and then things start going awry as I am on approach. I’m at the prescribed altitude at the right distance (or am I?), have entered the decision altitude etc in the FMS, switch on LS, then LOC, then to APPR (LOC goes off, logically) and it all looks fine. I drop the gear, apply flaps etc and the ■■■■ thing just flies at approach speed straight over the top of the runway without descending. Also, at times the autothrottle goes bonkers and does its own thing (or sometimes refuses any input whatsoever on final and just goes to full throttle and stays there no matter what I do with the keyboard or throttle levers (TM TCA Airbus). What am I missing? Have I got the aircraft misconfigured i.e. too late with the flaps etc (re the latter, the flap markers don’t seem to appear at the right times - but that might just be me being all over the place??). Based ono ATC instructions I go to the altitudes they advise, meaning I am now using Selected altitude, rather than Managed - is that throwing the LS off? All that said, I have landed the 320 using the LS before but I can’t work out what I’m doing wrong now? BTW, something odd (to me…) I noticed is that in the automatically generated flight plan, in the last stages it has the speed at 150kn for landing and then at altitude zero (the last line) it has an airspeed of 234kn, but that line does not appear in the FMS on the plane - not sure what that is about? I have noticed on a number o f occasions that there is a discrepancy between the generated FP and what shows in the FMS. On one occasion it showed all of the waypoints for a looping approach but the last 4 did not appear in the FMS, so when I passed the last waypoint (which was the destination airport itself) it tried to send me back on itself and went into this wide arc to nowhere… Any ideas on any of that? Sorry for the brain dump… I’ve run out of ideas…
When you activate the LS, do you see the Magenta diamond both on the horizontal plane and vertical plane? If you’re tuned in to the right frequency, it should appear, and when you press APPR button, the FMA should display both LOC and G/S as blue (armed). And when the horizontal magenta diamond are within range, the LOC will engage into active mode and will replace the NAV mode, and as the vertical magenta diamond passes the middle line, it would override the ALT mode and activate the G/S mode. You should feel a sudden pitch down as you capture the glide slope.
If you’re above the glideslope, it’s almost impossible to chase the glideslope without a sudden nose dive. So make sure you’re below the glideslope when you capture the signal. If you have access to ILS approach chart, it would tell you which altitude you should be in at what distance to capture the ILS signal appropriately.
Thanks!
After a bit more testing I have concluded that my key miss was not being on the Managed altitude, so it was holding the last Selected altitude (as directed by ATC…). That, combined with picking up the G/S as you describe looks like having done the trick and I can now land without a problem (accepting some manual intervention that may be required to deal with strong crosswinds etc).
Next topic for me is learning to execute regulation go-arounds. Let’s see how that goes…