DC10 crew had an near midair collision in ZOA class east.

Attributes
ACN	560406
Time
Date	200209
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	intersection : papee
State Reference	CA
Altitude	msl single value : 12000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa.artcc
Operator	common carrier : air carrier
Make Model Name	DC-10 30F
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival star : el nido 5
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 75 flight time total : 6000 flight time type : 350
ASRS Report	560406
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	conflict : nmac non adherence : required legal separation other anomaly other
Independent Detector	aircraft equipment : tcas other flight crewa other flight crewb
Resolutory Action	flight crew : took evasive action none taken : detected after the fact other
Miss Distance	horizontal : 0 vertical : 300
Supplementary
Problem Areas	Airspace Structure FAA Flight Crew Human Performance
Primary Problem	Airspace Structure

Narrative:

The aircrew received a TCASII RA while on the el nido five arrival into sjc at an assigned altitude of 12000 ft. The TCASII directed us to 'climb now' and showed traffic to be 300-400 ft below our position. At the same time that the captain initiated an evasive climb out of 12000 ft, ATC notified us of VFR traffic in our vicinity of unknown altitude. After the traffic was clear of conflict, the captain descended back down to 12000 ft and notified ATC of the position of the conflicting VFR traffic. ATC seemed surprised by the proximity of the 2 aircraft and even reconfirmed our altitude assignment of 12000 ft. Although it was a very clear day, none of the crew members saw the other aircraft. I feel that the captain did the right thing by trusting the TCASII and following its commands. TCASII works great, even on a clear day when you feel more comfortable trusting your eyesight.

Original NASA ASRS Text

Title: DC10 CREW HAD AN NMAC IN ZOA CLASS E.

Narrative: THE AIRCREW RECEIVED A TCASII RA WHILE ON THE EL NIDO FIVE ARR INTO SJC AT AN ASSIGNED ALT OF 12000 FT. THE TCASII DIRECTED US TO 'CLB NOW' AND SHOWED TFC TO BE 300-400 FT BELOW OUR POS. AT THE SAME TIME THAT THE CAPT INITIATED AN EVASIVE CLB OUT OF 12000 FT, ATC NOTIFIED US OF VFR TFC IN OUR VICINITY OF UNKNOWN ALT. AFTER THE TFC WAS CLR OF CONFLICT, THE CAPT DSNDED BACK DOWN TO 12000 FT AND NOTIFIED ATC OF THE POS OF THE CONFLICTING VFR TFC. ATC SEEMED SURPRISED BY THE PROX OF THE 2 ACFT AND EVEN RECONFIRMED OUR ALT ASSIGNMENT OF 12000 FT. ALTHOUGH IT WAS A VERY CLR DAY, NONE OF THE CREW MEMBERS SAW THE OTHER ACFT. I FEEL THAT THE CAPT DID THE RIGHT THING BY TRUSTING THE TCASII AND FOLLOWING ITS COMMANDS. TCASII WORKS GREAT, EVEN ON A CLR DAY WHEN YOU FEEL MORE COMFORTABLE TRUSTING YOUR EYESIGHT.

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.