Narrative:

This was a cross country training flight from rialto, ca, to sna, ca via pdz VOR (return flight). After departing runway 240 at rialto with a left crosswind departure, my student was to intercept the 010 degree radial from pdz and track inbound to pdz. He was slow had having difficulty getting oriented to the task. By the time he resolved his problems he had passed the 010 degree radial and was paralleling it. I suggested then proceeding direct to pdz by ctring the CDI and flying the course on the obs (180 degree to). This he did with the CDI slightly to the right. I felt comfortable that we were well outside the inner core of the ont arsa and also below the outer core at 2400 ft. As we continued sbound we contacted riverside tower advising them we were transitioning the west edge of their air traffic area north to south. They approved the transition and asked where we had departed from. We told them rialto and they informed us that ont had advised them of a possible airspace conflict with an aircraft on our route of flight -- an airliner had a TCASII alert on final into ont airport. While crossing the final approach path to ont at 2400 ft, 6 NM east, I had pointed out to my student a large aircraft descending to ont about 600 ft above us. I do not believe we violated any airspace but it is my resolve to increase my personal margins around arsa's to 3-4 mi and 500 ft below.

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Original NASA ASRS Text

Title: FLT CLOSE TO ARSA BOUNDARY CAUSES TCASII RA FOR ACR WITHIN THE ARSA.

Narrative: THIS WAS A XCOUNTRY TRAINING FLT FROM RIALTO, CA, TO SNA, CA VIA PDZ VOR (RETURN FLT). AFTER DEPARTING RWY 240 AT RIALTO WITH A L XWIND DEP, MY STUDENT WAS TO INTERCEPT THE 010 DEG RADIAL FROM PDZ AND TRACK INBOUND TO PDZ. HE WAS SLOW HAD HAVING DIFFICULTY GETTING ORIENTED TO THE TASK. BY THE TIME HE RESOLVED HIS PROBS HE HAD PASSED THE 010 DEG RADIAL AND WAS PARALLELING IT. I SUGGESTED THEN PROCEEDING DIRECT TO PDZ BY CTRING THE CDI AND FLYING THE COURSE ON THE OBS (180 DEG TO). THIS HE DID WITH THE CDI SLIGHTLY TO THE R. I FELT COMFORTABLE THAT WE WERE WELL OUTSIDE THE INNER CORE OF THE ONT ARSA AND ALSO BELOW THE OUTER CORE AT 2400 FT. AS WE CONTINUED SBOUND WE CONTACTED RIVERSIDE TWR ADVISING THEM WE WERE TRANSITIONING THE W EDGE OF THEIR ATA N TO S. THEY APPROVED THE TRANSITION AND ASKED WHERE WE HAD DEPARTED FROM. WE TOLD THEM RIALTO AND THEY INFORMED US THAT ONT HAD ADVISED THEM OF A POSSIBLE AIRSPACE CONFLICT WITH AN ACFT ON OUR RTE OF FLT -- AN AIRLINER HAD A TCASII ALERT ON FINAL INTO ONT ARPT. WHILE XING THE FINAL APCH PATH TO ONT AT 2400 FT, 6 NM E, I HAD POINTED OUT TO MY STUDENT A LARGE ACFT DSNDING TO ONT ABOUT 600 FT ABOVE US. I DO NOT BELIEVE WE VIOLATED ANY AIRSPACE BUT IT IS MY RESOLVE TO INCREASE MY PERSONAL MARGINS AROUND ARSA'S TO 3-4 MI AND 500 FT BELOW.

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.