ZOA center controller reported that an aircraft on the suutr two arrival missed a crossing restricti...

Narrative:

Aircraft X was a smf arrival descending on a STAR and a facility automated coordination with an adjacent sector (15); and entering my sector (34). Aircraft Y was a sfo arrival descending on the STAR as well. The two stars are procedurally separated (smf arrivals descend below sfo arrivals) which allows for the automated information transfer from sector to sector of the smf arrivals coming from S15. Aircraft Y was at FL300 descending on the dyamd arrival at the time and aircraft X was out of FL330 descending on the suutr arrival; was supposed to be below FL210 when the two arrivals cross path. The S15 controller called and mentioned aircraft X had missed his altitude crossing restrictions and was being stopped above aircraft Y. Aircraft X was stopped at FL320; aircraft Y was advised to increase the rate of descent to allow aircraft X to keep descending; as well as vectored away from aircraft Y's arrival path. Aircraft X was handed off and switched to nct descending to FL200 and on assigned heading instead of the arrival routing to avoid other potential traffic climbing out of approach control. The situation was alleviated because the S15 controller caught the aircraft X's late descent profile; but had he switched the flight to nct approach; aircraft X would have caused a potential disaster especially since the automated transfer procedure has them transferring frequencies to a different approach control sector from the sfo arrivals. Advise the pilots of better understanding the importance of meeting altitude/speed restrictions on stars; and what happens when they do not comply with these restrictions. Maybe a better descent altitude profile on the STAR instead of a 'dive' because the altitude restrictions on the suutr arrival from this direction display aircraft staying high and then doing a quick descent to meet the altitude restrictions (example: staying at FL360 until the last minute and then diving down to meet a restriction to cross a fix below FL210).

Original NASA ASRS Text

Title: ZOA Center Controller reported that an aircraft on the SUUTR TWO arrival missed a crossing restriction; creating a direct conflict with another aircraft on the DYAMD THREE arrival.

Narrative: Aircraft X was a SMF arrival descending on a STAR and a facility automated coordination with an adjacent sector (15); and entering my sector (34). Aircraft Y was a SFO arrival descending on the STAR as well. The two STARs are procedurally separated (SMF arrivals descend below SFO arrivals) which allows for the automated information transfer from sector to sector of the SMF arrivals coming from S15. Aircraft Y was at FL300 descending on the DYAMD arrival at the time and Aircraft X was out of FL330 descending on the SUUTR arrival; was supposed to be below FL210 when the two arrivals cross path. The S15 controller called and mentioned Aircraft X had missed his altitude crossing restrictions and was being stopped above Aircraft Y. Aircraft X was stopped at FL320; Aircraft Y was advised to increase the rate of descent to allow Aircraft X to keep descending; as well as vectored away from Aircraft Y's arrival path. Aircraft X was handed off and switched to NCT descending to FL200 and on assigned heading instead of the arrival routing to avoid other potential traffic climbing out of approach control. The situation was alleviated because the S15 controller caught the Aircraft X's late descent profile; but had he switched the flight to NCT approach; Aircraft X would have caused a potential disaster especially since the automated transfer procedure has them transferring frequencies to a different approach control sector from the SFO arrivals. Advise the pilots of better understanding the importance of meeting altitude/speed restrictions on STARs; and what happens when they do not comply with these restrictions. Maybe a better descent altitude profile on the STAR instead of a 'dive' because the altitude restrictions on the SUUTR arrival from this direction display aircraft staying high and then doing a quick descent to meet the altitude restrictions (example: staying at FL360 until the last minute and then diving down to meet a restriction to cross a fix below FL210).

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	1512167
Time
Date	201801
Local Time Of Day	0601-1200
Place
Locale Reference	ZOA.ARTCC
State Reference	CA
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR SUUTR TWO
Flight Plan	IFR
Aircraft 2
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Descent
Route In Use	STAR DYAMD THREE
Flight Plan	IFR
Person 1
Function	Enroute
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 6
Events
Anomaly	ATC Issue All Types Conflict Airborne Conflict Deviation - Altitude Crossing Restriction Not Met Deviation - Altitude Undershoot Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy

ZOA center controller reported that an aircraft on the suutr two arrival missed a crossing restriction; creating a direct conflict with another aircraft on the dyamd three arrival.