AN INST PLT; FLYING VFR IN THE LOS ANGELES BASIN; EXITED THE VFR CORRIDOR WITHOUT SCT'S PERMISSION.

Narrative

WAS UTILIZING SOCAL APCH FLT FOLLOWING ON A VFR FLT FROM SBP TO TOA. FLYING VFR ON TOP OF OVCST. WHEN I APCHED LOS ANGELES BASIN; I ASKED CTLR TO USE LAX SFRA GOING SW. CTLR TERMINATED FLT FOLLOWING JUST N OF SMO VOR AND ADVISED ME TO SQUAWK THE XPONDER CODE FOR USING LAX SFRA AND THE SFRA UNICOM FREQ. I THOUGHT HE WOULD STAY WITH ME TO S SIDE OF LAX SFRA (AS I HAVE DONE WITH FLT FOLLOWING MANY TIMES BEFORE). I WAS GOING TO ASK FOR VECTORS AND WAS CAUGHT UNPREPARED. GND WAS NOT VISIBLE FOR REF (BEING ABOVE THE OVCST). I WAS INADEQUATELY PREPARED TO NAV THE LAX SFRA BY THE SMO VOR (ON THE 132 DEG RADIAL). IT TOOK A MIN TO GET PREPARED AND GET SET UP. I WANDERED OFF A DIRECT COURSE ACROSS THE SFRA AREA GOING SW. ADDING TO MY CONFUSION WAS MY INABILITY TO KNOW WHEN I WAS IN; AND THEN CLR; OF THE LAX SFRA AS IT IS DEFINED BY GND REF (THAT I COULD NOT SEE BEING ABOVE THE OVCST). NEXT TIME; BETTER PREPARATIONS IN CASE FLT FOLLOWING IS TERMINATED UNEXPECTEDLY. WILL BE SET UP FOR OWN NAV AT ALL TIMES. RECOMMENDATIONS: 1) TO HAVE LAX SFRA N AND S BOUNDARIES DEFINED BY NAV FIXES (LAX VOR RADIALS XING THE SMO 132 DEG RADIAL FLT PATH WOULD BE GOOD) IN ADDITION TO GND REFS TO ENHANCE AWARENESS WHEN FLYING VFR ON TOP. 2) WHEN LAX IS OVCST; RECOMMEND SOCAL APCH TRY AND AVOID TERMINATING VFR FLT FOLLOWING UNTIL ACFT ACROSS TO AVOID SAME SIT. NOT A GOOD AREA IN WHICH TO BE LOST DUE TO CONFLICT WITH OTHER TFC.