While in a managed descent on the wahuu arrival to den; an A320 captain reports crossing sayge at 17...

Narrative:

During the descent into den while on the wahuu arrival with all crossing altitude restrictions verified. We had the aircraft in speed/ destination/ nav mode; at 17;230 feet we crossed sayge intersection and the aircraft auto switched into V/south -1;100 FPM. We got the 'degraded' aural warning and then switched the aircraft back into managed mode. It stayed in this mode the rest of the way down making all altitude crossings. This is the second time this has happened to me in the last week. I had the same thing happen in february while descending into bwi. This is why i'm filing it this time because it seems to be a pattern. Our crews should be made aware that this is happening and to use greater vigilance while in managed descent mode and to report it when it happens so that we can get airbus to do something about it!

Original NASA ASRS Text

Title: While in a managed descent on the WAHUU arrival to DEN; an A320 Captain reports crossing SAYGE at 17;230 feet when a chirp is heard and the autopilot reverts to V/S at -1100 FPM. VNAV is reengaged and performs normally for the remainder of the arrival.

Narrative: During the descent into DEN while on the WAHUU arrival with all crossing altitude restrictions verified. We had the aircraft in Speed/ Destination/ Nav mode; at 17;230 feet we crossed SAYGE intersection and the aircraft auto switched into V/S -1;100 FPM. We got the 'degraded' aural warning and then switched the aircraft back into managed mode. It stayed in this mode the rest of the way down making all altitude crossings. This is the second time this has happened to me in the last week. I had the same thing happen in February while descending into BWI. This is why i'm filing it this time because it seems to be a pattern. Our crews should be made aware that this is happening and to use greater vigilance while in managed descent mode and to report it when it happens so that we can get Airbus to do something about it!

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.

Attributes
ACN	1240192
Time
Date	201502
Local Time Of Day	0601-1200
Place
Locale Reference	D01.TRACON
State Reference	CO
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Component
Aircraft Component	FMS/FMC
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe

While in a managed descent on the wahuu arrival to den; an A320 captain reports crossing sayge at 17;230 feet when a chirp is heard and the autopilot reverts to V/south at -1100 FPM. VNAV is reengaged and performs normally for the remainder of the arrival.