A 'LTT' CREW; FLYING A VOR APCH TO KSMO; PREMATURELY DSNDED BELOW THE MDA; CAUSING A 'MSAW' TO BE ISSUED FROM TWR.

Narrative

THE VOR APCH WAS FIST ABANDONED DUE TO MY ERROR IN PROGRAMMING THE FMS. I WAS VECTORED BACK FOR ANOTHER ATTEMPT. I SET UP FOR A 'RAW DATA' APCH. DURING THE SECOND ATTEMPT I CONFIGURED THE ACFT TO EARLY FOR LNDG (FULL FLAPS) SO WHEN I LEVELED OFF AT THE 'MDA' I HAD TO ADD MORE PWR THAN NORMAL. I THEN MADE THE REALLY STUPID MISTAKE; I LEFT THE INSTS AND BEGAN LOOKING FOR THE ARPT SHORTLY AFTER THE ACFT SETTLED BELOW 'MDA' THUS CAUSING THE TWR TO CALL A 'LOW ALT' ALERT. THE TWO MAJOR ERRORS; ONE; I FAILED TO UTILIZE THE NON FLYING PLT AS AN AID DURING THE APCH; SO HE WAS OUT OF THE LOOP OF THE WHOLE APCH PROCESS. THE SECOND AND MOST SERIOUS (AND STUPID) WAS TO STOP FLYING BY REFERENCE TO INSTS AND FLY VISUALLY WHEN FORWARD VISIBILITY WAS IMPAIRED BY GLARE OF THE SUN (LOW) BROKEN CLOUD DECK AND MIST. IF I HAD JUST STAYED ON THE INSTS FLOWN THE APCH AS HAVE DONE MANY TIMES IN THE PAST THIS RPT WOULD NOT HAVE BEEN MADE. PROPER 'CRM' INCLUDING A THOROUGH APCH BRIEF OF DUTIES IS A MUST. THIS FLT DEPARTED VAN NUYS; IT IS A 10 MIN FLT; THE WORK LOAD FOR THE NPF IS VERY HIGH. HAD I NOT BEEN 'SO FAMILIAR' WITH THE PROCESSES I WOULD HAVE DONE A BETTER BRIEF. TRYING TO FLY 'SINGLE PLT' WAS VERY STUPID; BUT 'I KNEW' I COULD DO IT. I HAVE NEVER FELT SO UNPROFESSIONAL. MY SELF CONFIDENCE IS SHAKEN; BUT BY REVIEWING THE STEPS WHICH LEAD TO THIS HAD REINFORCED MY DETERMINATION TO REVIEW AND INSURE ALL CREW MEMBERS ARE ON 'THE SAME PAGE.'