ACR LGT FLC IN A NON COMPLIANCE WITH NOISE ABATEMENT PROC. DECIBEL RESTRICTION EXCEEDED.

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DURING CLBOUT FO SELECTED CLB-2 PWR AT 800 FT AGL IN ACCORDANCE WITH NOISE ABATEMENT PROCS AT SNA. THE THRUST RATING PANEL DID NOT CHANGE TO CLB-2 PWR AND FO NOTICED THAT G/A WAS ANNUNCIATED ON THE AUTO THROTTLE READOUT OF THE ADI. AT THIS TIME THE PITCH AND ROLL ANNUNCIATIONS ALSO READ GS TRACK AND LOC TRACK. THE AUTO THROTTLES REMAINED IN THE G/A MODE UNTIL THEY WERE MANUALLY DISCONNECTED. FLT DIRECTOR COMMANDS ALSO REMAINED COUPLED TO THE ILS UNTIL THE FLT DIRECTORS WERE BOTH CYCLED OFF; THEN ON. DUE TO G/A PWR VERSUS CLB-2 THE FLT PROBABLY EXCEEDED NOISE LIMITS FOR SNA. THE ONLY EXPLANATION FOR THE ACFT CAPTURING THE LOC BACK COURSE WOULD BE THE ARMING OF APCH MODE AFTER TKOF. NEITHER PLT ACTIVATED THE APCH SWITCH. THE THRUST RATING PANEL SHOULD HAVE SWITCHED TO CLB-2 REGARDLESS OF AUTOPLT FLT DIRECTOR MODES AT 800 FT AGL UPON SELECTION. THE SNA NOISE ABATEMENT PROC IS A RELATIVELY HIGH WORKLOAD PROC THAT MAKES PROPER AND TIMELY MODE SELECTION AND EXECUTION CRITICAL. THE LGT WDB AUTOFLT SYS DOES NOT ALLOW THE CREW TO DESELECT THE APCH (AFTER LOC AND GS CAPTURE) MODE UNLESS BOTH FLT DIRECTORS AND AUTOPLT IS DISENGAGED. THIS IS A DESIGN FLAW IN MY OPINION. THE CREW SHOULD BE ABLE TO USE ANY PITCH OR ROLL MODE TO FLY AWAY FROM THE LOC/GS. IF THE THRUST MGMNT PANEL IS IN G/A ANY OTHER SELECTION SHOULD EXECUTE IMMEDIATELY. WE ARE STILL TRYING TO ASCERTAIN THE SEQUENCE OF EVENTS THAT INHIBITED ENGAGEMENT OF CLB-2 MODE.