APPR not following G/S properly

I’ve recently been trying APPR with an A321. I have ensured that my ILS is tuned and set as source, but when APPR captures the G/S it does not follow it properly, and my diamond next to the altitude tape goes down. I have also ensured that I am below 250kts, below 3000ft and that I am below the glideslope. Am I doing something wrong? I suspected that I’m approaching the G/S at too high of an angle, so I have my procedures set and VNAV to descend roughly in line with the G/S, but that does not work.

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Could you send a video of this happening?

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One other thing to ensure is that you have intercepted and locked on to the localizer - your heading should be within 30 degrees of the localizer path when you cross it, then the LOC indicator will go green in the APPR control, and should steer you on to the beam.

The glideslope only locks on if the localizer is already locked.

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Should be below 170, not 250 knots; that’ll help you intercept it better. Also, I try to intercept below the glide scope as it creates a smoother intercept. Overall APPR can be wonky on some aircraft where they s turn until the catch the localizer. Hand fly it, much more fun and rewarding. 😎

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I’ve had it happen to me too I’ve heard it’s an issue because of the old physics or something along the lines of that.I fly the 319,320, and 321 a lot so what I’ve learned is if starts doing that disconnect the AP and fly it manually.

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All you need to do is have a long final, that is when APPR will work without a problem. Just be at 3000 feet, locked onto the localizer, then ALT that is yellow will turn into GS which will be green, then it will auto land.

Everybody who gave feedback, I will try this later on. Thanks!

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Manage to slow down at 210 kts selected. And activate the APPR phase in PERF.

Then, here is a generic sequence:

  • Set managed speed, the plane will slow down to green dot speed (~195 kts)
  • Set flaps 1, the plane will slow down to -S speed (~180 kts)
  • (the last 12 Nm) Set flaps 2, the plane will slow down to -F speed (~145 kts)
  • (the last 6 Nm or 2000 ft) Set gear down, then flaps 3 and full, the plane will slow down to Vapp (~135 kts)

If it is possible, 2 choices to capture glide slope (localizer is already intercepted):

  1. Set flaps 1 at G/S*
  2. Set gear down at G/S*

In USA you should often encounter the case 2.
But the ATC could decide another way. For example 160 kts until the last 4 Nm, so in this case your are flaps 2, gear down the last 6 Nm, and at 4 Nm managed speed flaps 3/full to be ready before the last 3 Nm (1000 ft).

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I have this problem more often than not on the A318, A319, A320 and A321. APPR works absolutely perfectly on all other aircraft equipped with it, but I don’t understand why it would only malfunction on these specific aircraft. I follow the exact protocol of approach that I do on say a 737-8, but in an A320 family plane it doesn’t work. The thing is that it works sometimes, but I can’t figure out what I do differently those times to times where it doesn’t work.

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Does this mean that the plane will slow down itself at these stages, or would I have to manage it myself? And how would I activate/display the green dot speed?

That’s done in the real Airbus the infinite flight one cannot do any of that if you want to replicate you’d have to do it manually and simulate green dot and speeds such as that


So there is no managed speed:
Set 195 kts
At G/S: flaps 1 set 180 kts
At 12 Nm: flaps 2 set 150 kts
At 6 Nm or G/S: gear down, flaps 3/full, set 140 kts.

That’s a helpful chart. Thanks!

I tried it with a 737 and that speed chart. Worked like a charm. Thanks again!

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