A320
Air Traffic Control Fully Certified
Other / Unknown
ATC Issue All Types; Conflict Airborne Conflict
General None Reported / Taken
Airspace Structure; Procedure
An A320 was on ILS 26L into ONT just past PETIS NDB descending out of 3;400. I observed a VFR target without transponder from north of Highway 10 southbound going to cross the ONT final and issued traffic to the A320. I offered the A320 a vector around the traffic and he declined. The traffic did not merge; but only just barely. This is a known VFR transition area just below the Class C at ONT. The traffic was clear of the A320 and I transferred communication to ONT. Subsequently I called RAL Tower and asked if they were talking to the aircraft without transponder; they were and I asked the altitude of the aircraft. They advised he said he was at 2;200. This is an all too common problem at ONT; what I would suggest is that we protect the aircraft on the ONT final better and have the east extension of ONT's Class C be down to the surface out to PETIS NDB. This problem needs to be addressed before something does happen on the final into ONT.
SCT Controller described a conflict event involving Air Carrier traffic inbound to ONT on the ILS 26L and VFR traffic crossing the ILS path; the reporter recommending ONT's Class C be expanded to reduce same type events.