A B737-700 PLT DEPARTING SNA RPTS VISUALLY CLRING TFC AND CLBING WITH CUTBACK PWR.

Narrative

NIGHT VMC SNA NOISE ABATEMENT DEP TO 5000 FT ASSIGNED ALT. TWR DIRECTED SWITCH TO DEP CTL DURING CUTBACK PROC. UPON CONTACT; SOCAL DEP CTL DIRECTED US TO MAINTAIN 3000 FT. THEY THEN ADVISED US OF TFC AT 3500 FT IN OUR 2 O'CLOCK POS; A C152. WE RESPONDED WITH THE TFC IN SIGHT. PRIOR TO ALT ACQUIRED; SOCAL DIRECTED US TO MAINTAIN VISUAL AND CLB TO 10000 FT. WE DIALED 10000 FT INTO THE ALT SELECTOR AND CONTINUED OUR CLB. WE WERE APPROX 2.5 DME ON THE SNA LOC AND PASSING 2500 FT. PWR WAS AT THE CUTBACK SETTING AND AIRSPD WAS V2 +20 KTS. WE CONTINUED THE CLB AND TURNED AWAY FROM THE TFC WHICH WAS CONTINUOUSLY IN SIGHT. IN RETROSPECT; MAINTAINING 3000 FT AND PASSING BELOW THE CESSNA WOULD HAVE BEEN MORE PRUDENT. I SUSPECT ATC WANTED US TO CONTINUE THE CLB TO FACILITATE NOISE ABATEMENT OVER THE NEWPORT BEACH COMMUNITY. THIS WAS ALSO IN THE BACK OF OUR MINDS. FURTHER; WE WANTED TO CONTINUE THE CLB BECAUSE OF A SIMILAR EVENT ON A PREVIOUS FLT. ON THAT SNA DEP; SOCAL ALSO DIRECTED A 3000 FT LEVELOFF. PRIOR TO 6 DME; AND AFTER ALT ACQUIRE OCCURRED; WE WERE DIRECTED TO CLB TO 10000 FT. SELECTING LEVEL CHANGE ENGAGED N1; DRIVING THE THROTTLES BEYOND CUT-BACK. WE ALLOWED THE THROTTLES TO ADVANCE TO N1. OUR THOUGHT WAS THAT THE HOLD DOWN WAS FOR TFC AND WE WANTED TO SCAN OUTSIDE AS WE APCHED THE COASTLINE RATHER THAN DEALING WITH THE DISTR OF DISENGAGING N1 AND RE-ESTABLISHING CUT-BACK PWR AGAIN. CONSEQUENTLY; ON THIS SUBSEQUENT DEP; WE HAD A BIAS TO CONTINUE THE CLB IN THE NOISE ABATEMENT PROFILE. RECOMMENDATION: AN ATC DIRECTED LEVELOFF OUT OF SNA IS PROBABLY DUE TO TFC. IF SOCAL DEP ISSUES A 'MAINTAIN VISUAL AND CLB' DIRECTION; CONSIDER REFUSING THE CLB AND ALLOW ATC TO MAINTAIN TFC SEPARATION. IF ALT ACQUIRED HAS OCCURRED AND THE CREW ELECTS TO CLB EITHER: 1) SELECT LEVEL CHANGE; ALLOW FULL PWR AND DISREGARD THE NOISE ABATEMENT PROFILE (CLBING IN A FAMILIAR CONFIGN WOULD MINIMIZE COMPLICATIONS AND ALLOW FOR MORE THOROUGH TFC SCANNING); OR 2) SELECT LEVEL CHANGE AND DESELECT N1 AND MANUALLY POS THE THROTTLES TO THE CUTBACK SETTING; OR 3) SELECT VERT SPD 500 AND CLB OUT WITH THE RESULTING REDUCED PWR SETTING UNTIL REACHING 6 DME AND THEN SELECT LEVEL CHANGE OR VNAV PER THE SNA PROFILE.