A B737-300 OVERSHOT ITS ASSIGNED HDG DURING A VECTORED DEP PROC FROM SNA.

Narrative

FLT DEPARTED SNA. SOCAL RAPCON INSTRUCTED FLT TO HEAD 200 DEG VECTOR. COPLT ACCURATELY READ BACK 200 DEGS AND INSERTED 200 DEGS IN FLT DIRECTOR MCP. CAPT MISHEARD 200 DEGS AS 270 DEGS AND BEGAN TURN. ENSUING COCKPIT ACTIVITY ALLOWED 270 DEG TURN TO BE COMPLETED AND SOCAL RAPCON ISSUED A TFC ALERT AND CALLED FOR IMMEDIATE L TURN. TFC WAS VISUALLY ACQUIRED AND DEP CONTINUED. UPON ARR IN LAS; CAPT CALLED SOCAL AND WAS INFORMED OF NO CONFLICT OF SAFETY WHICH REQUIRED RPTING. CONCLUSION: ACR MGMNT SHOULD BE TAKEN TO TASK FOR 90+ FLT HR SCHEDULES; OFTEN 'BACK SIDE OF CLOCK' AND ENSUING FATIGUE; ILLNESS AND INATTN BY FLT DECK CREW MEMBERS. SAFETY SHOULD BE OTHER THAN 'LIP SVC' BY MAJOR AIRLINE MGMNT! SUPPLEMENTAL INFO FROM ACN 414659: THE NOISE ABATEMENT PROC OUT OF SNA IS COMPLEX AND DEMANDING. THE AIRSPACE SURROUNDING THE WEST COAST IS CROWDED WITH VFR ACFT; REQUIRING A CONSTANT OUTSIDE SCAN. ALSO; AFTER BEING GIVEN THE 200 DEG HDG; THE FLT DIRECTOR GUIDANCE BARS DISENGAGED CAUSING A MOMENTARY DISTR.