B787 flight crew reported FMS VNAV system malfunction on arrival; and using vertical speed to fly th...

Attributes
ACN	1589725
Time
Date	201810
Local Time Of Day	0001-0600
Place
Locale Reference	LAX.Airport
State Reference	CA
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	B787 Dreamliner Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	First Officer Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 100 Flight Crew Total 13000 Flight Crew Type 742
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Instrument
Experience	Flight Crew Last 90 Days 210 Flight Crew Total 32800 Flight Crew Type 1037
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Altitude Crossing Restriction Not Met Deviation - Procedural Clearance

Narrative:

During the descent phase into lax; on the GOATZ1 arrival; the FMS VNAV system would not work. Our first indication of this fact was that we never had a TOD when in the cruise phase. We were given a clearance to cross goatz at 16;000; but the FMS would not let us enter it; no matter what format we used. We also never had a vertical situation display. We were then given a clearance to descend via the GOATZ1. Part of the distraction to us was the fact that the ATIS said that 25L; the normal runway we would be given from that direction; was closed. During the course of our arrival we were given at least four runway changes between runway 25L and 25R. During the arrival; due to the fact that I was flying the altitude restrictions using flch and V/south; we crossed dirby lower than 16;000 and bufie higher than 8;000.

Original NASA ASRS Text

Title: B787 flight crew reported FMS VNAV system malfunction on arrival; and using vertical speed to fly the STAR.

Narrative: During the descent phase into LAX; on the GOATZ1 arrival; the FMS VNAV system would not work. Our first indication of this fact was that we never had a TOD when in the cruise phase. We were given a clearance to cross GOATZ at 16;000; but the FMS would not let us enter it; no matter what format we used. We also never had a Vertical Situation Display. We were then given a clearance to descend via the GOATZ1. Part of the distraction to us was the fact that the ATIS said that 25L; the normal runway we would be given from that direction; was closed. During the course of our arrival we were given at least four runway changes between runway 25L and 25R. During the arrival; due to the fact that I was flying the altitude restrictions using FLCH and V/S; we crossed DIRBY lower than 16;000 and BUFIE higher than 8;000.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.