Narrative:

We were flying into sna on the kayoh 5 arrival to runway 19R. During the arrival at 8;000 feet; socal vectored the flight off the STAR to a 290 degree heading. After assigning the heading; socal indicated that there was traffic at 12 to 1 o'clock; but; the traffic's altitude was unverified. Both the captain and first officer looked for the traffic in the direction given by ATC. Seeing nothing; the crew looked at the TCAS. No targets were shown on the TCAS. The first officer had been hand flying the aircraft since 18;000 feet on a clear; sunny; late afternoon. Socal then issued a clearance to slow to 190 knots; then; descend to 6;600 feet. The first officer started to slow from 220 knots at idle power; and; at 190 knots started to descend to 6;600 feet. About this time; socal again stated there was traffic at 12-1 o'clock; altitude unverified. The captain was the first to notice the aircraft immediately followed by the first officer gaining visual. The traffic was less than a mile at 1 o'clock nose on. The piper aircraft flew directly over us at about 8;000 feet. Once the traffic passed; the first officer noted that the altimeter was passing 7;600 feet and still in our descent. Our planes missed by 300-500 feet. The aircrew informed socal of the near miss. Socal indicated that his radar scope still had no transponder readout from the civilian aircraft. Upon landing; the captain called the socal supervisor. Per the socal supervisor; the aircraft had previously violated class B airspace at lax as well. Now the same aircraft was in the arrival corridor to sna. Socal had no communication with the aircraft we had passed.

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Original NASA ASRS Text

Title: A319 flight crew experiences a NMAC descending out of 8;000 feet during the KAYOH 5 arrival to SNA. The intruder was a fixed gear Piper eastbound at 8;000 feet without a transponder and had reportedly passed through LAX Class B earlier without a clearance to do so.

Narrative: We were flying into SNA on the KAYOH 5 arrival to Runway 19R. During the arrival at 8;000 feet; SoCal vectored the flight off the STAR to a 290 degree heading. After assigning the heading; SoCal indicated that there was traffic at 12 to 1 o'clock; but; the traffic's altitude was unverified. Both the Captain and First Officer looked for the traffic in the direction given by ATC. Seeing nothing; the crew looked at the TCAS. No targets were shown on the TCAS. The First Officer had been hand flying the aircraft since 18;000 feet on a clear; sunny; late afternoon. SoCal then issued a clearance to slow to 190 knots; then; descend to 6;600 feet. The First Officer started to slow from 220 knots at idle power; and; at 190 knots started to descend to 6;600 feet. About this time; SoCal again stated there was traffic at 12-1 o'clock; altitude unverified. The Captain was the first to notice the aircraft immediately followed by the First Officer gaining visual. The traffic was less than a mile at 1 o'clock nose on. The Piper Aircraft flew directly over us at about 8;000 feet. Once the traffic passed; the First Officer noted that the altimeter was passing 7;600 feet and still in our descent. Our planes missed by 300-500 feet. The aircrew informed SoCal of the near miss. SoCal indicated that his radar scope still had no transponder readout from the civilian aircraft. Upon landing; the Captain called the SoCal Supervisor. Per the SoCal Supervisor; the aircraft had previously violated Class B Airspace at LAX as well. Now the same aircraft was in the arrival corridor to SNA. SoCal had no communication with the aircraft we had passed.

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.