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invernyx / md11-bugs

The official bug tracker for the TFDi Design MD-11
https://tfdidesign.com/md11.php
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[BUG] - AFS not honouring ALT in window #1277

Open KJA1582 opened 1 month ago

KJA1582 commented 1 month ago

Describe the bug

When changing the INIT Page altitudes, AFS commands climb thrust and pitches upwards even though AFS ALT window value has not changed

Steps to reproduce

Establish cruise with INIT Page crz level and AFS ALT window matching Increase INIT page crz level observe climb

Expected behaviour

AFS honouring AFS ALT window

Evidence

https://youtu.be/2nmX5waF0lg

File too big for GH

Simulator

Microsoft Flight Simulator 2020 (MSFS)

Crash

No

Phase of flight

Cruise

Pitch

3°

Bank

0°

Heading

287

Altitude

FL320

Departure

OMDB

Arrival

EDDF

Cruise level

FL320

ZFW

199848 kgs

CG

24.1

Fuel

42950 kgs

Cost index

80

Route

OMDBEDDF_PDF_1716904292.pdf

Location

19nmi before SRT

Agreement

turbofandude commented 1 month ago

This will be solved by causing a new cruise altitude > your altitude to revert to CLB mode (it'll also fix the lack of CLB THRUST during S/C)

KJA1582 commented 1 month ago

Yes, but shouldn't AFS not actually climb if the window is lower then the target? Unless switching from CRZ to CLB mode fixes this

joon44 commented 1 month ago

Yes, but shouldn't AFS not actually climb if the window is lower then the target? Unless switching from CRZ to CLB mode fixes this

ALT window is always the absolute ceiling or floor altitude the plane climbs/descends to. Theres only exception for engine driftdown.