PA28 on vectors for approach has near midair collision with twin opposite direction and climbing.

Attributes
ACN	334993
Time
Date	199603
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : san
State Reference	CA
Altitude	msl bound lower : 2500 msl bound upper : 2500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : san
Operator	general aviation : personal
Make Model Name	PA-28 Cherokee/Archer II/Dakota/Pillan/Warrior
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : private pilot : instrument
Experience	flight time last 90 days : 30 flight time total : 700 flight time type : 500
ASRS Report	334993
Person 2
Affiliation	Other
Function	flight crew : single pilot
Events
Anomaly	conflict : nmac
Independent Detector	other flight crewa
Resolutory Action	flight crew : took evasive action other
Consequence	Other
Miss Distance	horizontal : 200 vertical : 50
Supplementary
Primary Problem	Ambiguous

Narrative:

En route to san from bullhead city. We were being vectored above an area of san diego called mission valley, given vectors for sequencing into san, behind commercial traffic. VMC, cavu, on a weekday. I was PIC, other pilot was under hood (goggles) for currency flight training. ATC was calling 2-3 targets as we entered class B from northeast. However, a target suddenly appeared at our 12 to 1 O'clock position, without any traffic call. It was a light twin aircraft climbing through our altitude, heading east, and coming right at us. I grabbed the control and made a sharp left turn to avoid the aircraft. Ballpark horizontal clearance was 200 ft. No call was ever received from ATC, nor did we ever tell her. Her sector was non-stop chatter, and she was in constant communication with some aircraft. She was extremely busy. I know the other aircraft never saw us. Without evasive action it would have been a fatal incident. I believe this aircraft might/could have just departed runway 27 at san, and was executing a climbing right turn, through our altitude and heading. Quite possibly they never switched from control tower to ATC after departure to get traffic call (us), or they executed turn without/prior to switching frequencys. Who knows?

Original NASA ASRS Text

Title: PA28 ON VECTORS FOR APCH HAS NMAC WITH TWIN OPPOSITE DIRECTION AND CLBING.

Narrative: ENRTE TO SAN FROM BULLHEAD CITY. WE WERE BEING VECTORED ABOVE AN AREA OF SAN DIEGO CALLED MISSION VALLEY, GIVEN VECTORS FOR SEQUENCING INTO SAN, BEHIND COMMERCIAL TFC. VMC, CAVU, ON A WEEKDAY. I WAS PIC, OTHER PLT WAS UNDER HOOD (GOGGLES) FOR CURRENCY FLT TRAINING. ATC WAS CALLING 2-3 TARGETS AS WE ENTERED CLASS B FROM NE. HOWEVER, A TARGET SUDDENLY APPEARED AT OUR 12 TO 1 O'CLOCK POS, WITHOUT ANY TFC CALL. IT WAS A LIGHT TWIN ACFT CLBING THROUGH OUR ALT, HEADING E, AND COMING RIGHT AT US. I GRABBED THE CTL AND MADE A SHARP L TURN TO AVOID THE ACFT. BALLPARK HORIZ CLRNC WAS 200 FT. NO CALL WAS EVER RECEIVED FROM ATC, NOR DID WE EVER TELL HER. HER SECTOR WAS NON-STOP CHATTER, AND SHE WAS IN CONSTANT COM WITH SOME ACFT. SHE WAS EXTREMELY BUSY. I KNOW THE OTHER ACFT NEVER SAW US. WITHOUT EVASIVE ACTION IT WOULD HAVE BEEN A FATAL INCIDENT. I BELIEVE THIS ACFT MIGHT/COULD HAVE JUST DEPARTED RWY 27 AT SAN, AND WAS EXECUTING A CLBING R TURN, THROUGH OUR ALT AND HDG. QUITE POSSIBLY THEY NEVER SWITCHED FROM CTL TWR TO ATC AFTER DEP TO GET TFC CALL (US), OR THEY EXECUTED TURN WITHOUT/PRIOR TO SWITCHING FREQS. WHO KNOWS?

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.