Narrative:

Air carrier inbound on OAKES2 arrival to oakland international airport (oak) at 6;000 feet had to respond to a TCAS RA approximately 15 miles east of oak due to a VFR aircraft that was on a 1200 code southeast bound indicating 5;500 feet. The 5;500 foot traffic was issued to the air carrier approximately 10 miles prior to their merging point and the air carrier reported that he had; 'traffic in sight.' within about 8 miles of their merging point. At the merging point; the air carrier responded to a TCAS RA and climbed to an altitude of about 6;300 feet. The VFR aircraft at 5;500 feet was not in communication with nct approach.the san francisco (sfo) class B airspace does not provide adequate airspace protection for oakland arrival traffic. It allows VFR aircraft to fly directly into the path of IFR commercial aircraft that are descending into oakland without any communication with ATC. This is a severe deficit in the national airspace system and it may result in a midair collision someday.I recommend lowering the sfo class B shelves. The 8;000-10;000 foot shelf should be lowered to 6;000 feet. The 6;000-10;000 foot shelf should be lowered to 4;000 feet. And the 4;000-10;000 foot shelf should be lowered to 3;000 feet. This would protect the oakland final approach traffic; but still would allow VFR aircraft to fly underneath the class B airspace.

Related reports:

Google
 

Original NASA ASRS Text

Title: Aircraft on IFR arrival route responded to a TCAS/RA to avoid a VFR aircraft. TRACON had issued the traffic to the IFR arrival pilot and the pilot reported the traffic in sight. The IFR arrival aircraft was restricted to 6;000 feet to stay above the VFR target who's Mode C indicated 5;500 feet. The reporter states this is a routine occurrence in this area as the overlying Class B Airspace does not provide protection for this airport's arrival routes.

Narrative: Air carrier inbound on OAKES2 Arrival to Oakland International Airport (OAK) at 6;000 feet had to respond to a TCAS RA approximately 15 miles east of OAK due to a VFR aircraft that was on a 1200 code southeast bound indicating 5;500 feet. The 5;500 foot traffic was issued to the air carrier approximately 10 miles prior to their merging point and the air carrier reported that he had; 'Traffic in sight.' within about 8 miles of their merging point. At the merging point; the air carrier responded to a TCAS RA and climbed to an altitude of about 6;300 feet. The VFR aircraft at 5;500 feet was not in communication with NCT approach.The San Francisco (SFO) Class B airspace does not provide adequate airspace protection for Oakland arrival traffic. It allows VFR aircraft to fly directly into the path of IFR commercial aircraft that are descending into Oakland without any communication with ATC. This is a severe deficit in the National Airspace System and it may result in a midair collision someday.I recommend lowering the SFO Class B shelves. The 8;000-10;000 foot shelf should be lowered to 6;000 feet. The 6;000-10;000 foot shelf should be lowered to 4;000 feet. And the 4;000-10;000 foot shelf should be lowered to 3;000 feet. This would protect the Oakland final approach traffic; but still would allow VFR aircraft to fly underneath the Class B airspace.

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.