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digidax
02-28-2017, 12:54 PM
Hi,
here it's the scenario / flightplan:

Lateral: Takeoff on EDDF RWY 23L, SID SONEB 5T to SONEB, after right turn DIR TO "BOT", finishing approach back to 25L via METMA
Vertical: CRZ Level: 4000 ft

ILS: dent: IDSW with 109.90 checked on RNAV

APPR Phase: DH: NO or Empty, all other Points like QNH .. are set.
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After Takeoff, AP1 activated, 5 NM before BOT, pressing the ILS Button. IDSW is identified. After right turn to Wpt METMA, pressing APPR button.
G/S and LOC are captured and engaged. Activating AP2. FMGS is following ILS but no CAT III dual ist displaying in the 4 th FMA column.

Aircraft is following ILS. FMA displays LAND. PAPI indicator shows 2 white and 2 red.
Around 1 NM before RWY 23L, the magenta G/S indicator is going faster down and the aircraft is NOT following.

If I do not take over for manual landing and bring down the bird, the FMGS goes to Go Around Phase and starts a missed approach procedure correctly.

I have read the FCOM but have no idea what's going wrong. Like a normalflight from EDDC to EDDL, CAT's are shown and AUTO LAND is possible.
The only thing what's different is, is that there was no DECEND phase after CRZ.

I will now make a test flight with the CRZ level of 5000 ft and then make a DECEND phase to 4000 ft on BOT to catch the glide path intersection.

best regards Frank

digidax
02-28-2017, 04:03 PM
So, speculation confirmed: 4 Touch and Go's, two on 23L and two on 23R, with a DECEND phase before APPR Phase CAT III dual ist displaying in the 4 th FMA column and AUTO LAND is successful done.

So the question, is it a bug or a feature?

best regards, Frank

jeehell
03-01-2017, 02:32 PM
Probably you forgot to activate approach phase in the MCDU.

digidax
03-01-2017, 05:19 PM
Probably you forgot to activate approach phase in the MCDU.

You're right. The scenario I have drawn is comparable like a missed approach procedure. This is descripted in FCOM: PRO-NOR-SRP-01-80-00004057.0008001 / 14 FEB 11

That's why a decend phase is not activated and so a approach phase is not following. For this matter, I have manually activate in MCDU the approach phase and have also to check if it's activated before trusting in a successful Cat III autoland.

Thanks, Frank