B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 275
ATC Issue All Types; Conflict NMAC
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Human Factors; Airspace Structure; Procedure
We were on the HYP 5 STAR to SJC.  At 8;000 feet MSL and two NM prior to GILRO; NorCal issued clearance direct KLIDE.  ATC called out traffic that was observed at 8;500 feet MSL.  Flight crew did not visually see traffic.  ATC issued a 30 degree left turn to avoid traffic but then cancelled that clearance and issued a descent clearance to 6;500 feet MSL.  We received a TCAS RA with contact +400 and a RA descend command.   TCAS traffic was visually acquired by flight crew (GA low-wing prop with red/white paint scheme).  We were in a descent while performing a 5 to 10 degree right turn.  Conflicting traffic was observed descending as well and turning slightly left to keep aligned with our course.  Conflicting aircraft passed directly overhead +400 from our aircraft traveling the opposite direction. Increase FAA education of pilots in the NorCal area.  Highlight high density arrival corridors; proper communication procedures; discuss benefits of VFR flight following; and review proper procedures for a TCAS RA event.
B737-700 Captain experiences a NMAC with a light aircraft at 8;000 feet near GILRO. TCAS issued a descend RA and the Captain believes that the intruder was also descending. Both aircraft maneuvered to fly reciprocal courses.