Problem with NPA managed/managed

[FraPre 89]

Hello,

for testing i will fly an NPA (NDB Approach) managed/managed. My routing from EDDF to EDDH i leave at the transition for vectoring to final approach. All FMCU entries at PERF APP Page and F/PLN Page are correctly, APPR Phase is activated. At the last segment before final approach i fly with intercept heading and will descend (selected with V/S) from 5000 to 3000 (FAF alt). At the DIR Page i choose DIR TO FAF with inbound radial and the intercept point are calculated and showed on ND, the Flighplan is automatic sequenced.

With "clear for NDB approach" i push APPR on the intercept leg and the FMA showed direct FINAL APP, the descend discontinoues, and the airplane is level off at the actually alt (as sample 4100 ft). The further fly to intercept point and to FAF is lateral correctly, but the descend to DA(H) starts now to early and partly outside of final approach leg.

I´ think, with push APPR the correctly modes at first on the intercept leg are ALT (FINAL) and APP NAV and at FAF FINAL APP?

Fly with FAF alt (3000 ft) on the intercept leg is the same.

Where is the fallacy?

Best regards

Frank

(i hope, my english is anderstandable)

[The Dude 6537]

Your english is perfectly understandable.

Could you try DIR TO without radial in please. And just to be sure, first select APPR on the FCU when you are at 3000. And which approach did you select in the MCDU (full correct name please).

Please report back with your findings. Thanks.

[FraPre 89]

Hi Frank,

the fly with FAF altitude (3000 ft) at intercept leg and set DIR TO FAF (ALF10) without IN - radial brings no succes (respective flight mode). With push APPR on FCU, the mode change direct to FINAL APP, the plane fly now direct to ALF10 and holds the altitude (3000 ft). At ALF10 the plane intercepts the selected approach track and beginns with alive the V/DEV Brick according to descend.

The selected approach at first is for EDDH ILS15/ via NOL15; before reach NOLGO i change to HDG selected to LBE VOR and set the new approach NDB15/ via LBE. I fly via HDG to LBE, than with HDG 331 outbound (and parallel to the rwy track) for 10-15 NM, then set intercept HDG 091 to 101. This intercepts the approach track few miles before FAF.

Best regards

Frank

[The Dude 6537]

When I see your pics everything is going the way it should. What exactly is your problem here?

[FraPre 89]

Maybe no problem, but the question, is the directly mode change in FINAL APP on the intercept leg, far before intercept point reached, correctly?

The manuals "speaks" first from mode FINAL and NAV APP and at the FAF from FINAL APP.

On descend to FAF altitude and fly on intercept leg to final approach course the descend is stopped and the plane fly with actually alt. I means, the plane must continous the before selected descend to showed value in the ALT window.

I means this FCTM (Page 183 - 185)

http://www.737ng.co.uk/A320%20321%20FCTM%20Flight%20Crew%20Training%20Manual.pdf

Maybe, this function is not correctly simulated - o.k., that´s the way it is.

Best regards

Frank

[Joshua Che. 1601]

Due to the limitations of the navdata format, we wont change this.

[FraPre 89]

Thanks!

Best regards

Frank