A320 descending into sac is confused by ZOA with company traffic landing sfo.

Attributes
ACN	583927
Time
Date	200306
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zoa.artcc
State Reference	CA
Altitude	msl bound lower : 12000 msl bound upper : 14000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa.artcc tracon : nct.tracon
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	descent : approach descent : intermediate altitude
Route In Use	arrival star : flunk
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zoa.artcc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 120 flight time total : 18000 flight time type : 2000
ASRS Report	583927
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne less severe non adherence : published procedure other anomaly other
Independent Detector	aircraft equipment : tcas other flight crewa
Resolutory Action	controller : issued new clearance other
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	ATC Human Performance

Narrative:

We had another aircraft going into sfo with similar call sign with ours, that was confused with our descent into sacramento. We requested lower altitude to make the swr VORTAC at FL240, or below. ZOA descended us to FL310 and said we would not get that restr at swr. We finally got clearance down to FL240 and a frequency change to lower sector. When the first officer checked in, he gave us lower altitude of 14000 ft and an altimeter setting for sfo. First officer said that was odd that they gave us sfo altitude 29.80. This was our first clue, but we did not do anything about it. As we continued into sacramento, we got a TCASII alert and got a visual on that aircraft (light twin). This was about the time ZOA discovered our (ie, his and ours) mistake. We requested a lower altitude and center said, 'air carrier X I gave you 11000 ft.' we said, 'no, air carrier Y requested lower.' center said, 'where are you?' I said that we are descending into sacramento. He gave us a new frequency for norcal approach, which gave us 12000 ft and heading 250 degrees. They also advised us that the twin had a visual on us. As we started out descent to 12000 ft, we got an RA, but our descent was already below the required by the RA, which shortly came back with, clear of conflict. We continued into sacramento to normal landing. This was caused by similar call signs and center not noticing at our check in, and gave us descent meant for air carrier Y into sfo.

Original NASA ASRS Text

Title: A320 DESCENDING INTO SAC IS CONFUSED BY ZOA WITH COMPANY TFC LNDG SFO.

Narrative: WE HAD ANOTHER ACFT GOING INTO SFO WITH SIMILAR CALL SIGN WITH OURS, THAT WAS CONFUSED WITH OUR DSCNT INTO SACRAMENTO. WE REQUESTED LOWER ALT TO MAKE THE SWR VORTAC AT FL240, OR BELOW. ZOA DSNDED US TO FL310 AND SAID WE WOULD NOT GET THAT RESTR AT SWR. WE FINALLY GOT CLRNC DOWN TO FL240 AND A FREQ CHANGE TO LOWER SECTOR. WHEN THE FO CHKED IN, HE GAVE US LOWER ALT OF 14000 FT AND AN ALTIMETER SETTING FOR SFO. FO SAID THAT WAS ODD THAT THEY GAVE US SFO ALT 29.80. THIS WAS OUR FIRST CLUE, BUT WE DID NOT DO ANYTHING ABOUT IT. AS WE CONTINUED INTO SACRAMENTO, WE GOT A TCASII ALERT AND GOT A VISUAL ON THAT ACFT (LIGHT TWIN). THIS WAS ABOUT THE TIME ZOA DISCOVERED OUR (IE, HIS AND OURS) MISTAKE. WE REQUESTED A LOWER ALT AND CTR SAID, 'ACR X I GAVE YOU 11000 FT.' WE SAID, 'NO, ACR Y REQUESTED LOWER.' CTR SAID, 'WHERE ARE YOU?' I SAID THAT WE ARE DSNDING INTO SACRAMENTO. HE GAVE US A NEW FREQ FOR NORCAL APCH, WHICH GAVE US 12000 FT AND HEADING 250 DEGS. THEY ALSO ADVISED US THAT THE TWIN HAD A VISUAL ON US. AS WE STARTED OUT DSCNT TO 12000 FT, WE GOT AN RA, BUT OUR DSCNT WAS ALREADY BELOW THE REQUIRED BY THE RA, WHICH SHORTLY CAME BACK WITH, CLR OF CONFLICT. WE CONTINUED INTO SACRAMENTO TO NORMAL LNDG. THIS WAS CAUSED BY SIMILAR CALL SIGNS AND CTR NOT NOTICING AT OUR CHK IN, AND GAVE US DSCNT MEANT FOR ACR Y INTO SFO.

Data retrieved from NASA's ASRS site as of July 2007 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.