Narrative:

Final leg (mod-oak) on 135 cargo flight with a familiar route. Radar vectors to join airway, climb and maintain 6000 ft. After departing mod, handed off to norcal approach controller and told to climb and maintain 5000 ft. I read back 5000 ft and set my altitude reminder bug from 6000 ft to 5000 ft (just indicates value, no warnings). While climbing through about 3500-4000 ft, I began concerning myself with the inevitable approach into oak. I knew the WX was IFR and I began preparation tasks for the approach (picked up ATIS and leafing through the charts in my binder). I passed through 5000 ft and continued to 6000 ft, the original altitude. Upon reaching 6000 ft, the controller gave me a vector for traffic and reminded me that I'd been assigned 5000 ft. I felt sick to my stomach as I realized my error. I turned to the new heading and told the controller I was descending to 5000 ft immediately. He agreed that would be desirable. The altitude bug indicated 5000 ft and I remembered reading back 5000 ft. About 5 mins later, the conflicting traffic passed at my 3 O'clock position, maybe 10 mi away. Traffic was no factor, but that was due to the controller's vigilance and pre-emptive action. The controller asked me if I'd read back 5000 ft to him. I told him, yes I had, the mistake was totally my fault, and I apologized for creating the situation. The controller said nothing more about it, handed me off to the next controller, and the rest of the flight passed without incident. The lessons I'm taking away from this incident are numerous. You must constantly guard against complacency. I was complacent about my regular clearance, not challenging my presumptions, and taking the phase of flight for granted. I got ahead of myself and became preoccupied with my approach and didn't pay attention to where I was and what I was doing at the moment. I need to change some procedures or at least incorporate things more effectively. The altitude bug will become an active part of my scan and not just used passively for reference. I will challenge what I'm doing more and remind myself '1000 ft to go.' most importantly I need to put first things first, not get too far ahead of myself, and focus on the task at hand. I need to ask questions and guard against complacency.

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Original NASA ASRS Text

Title: A BE99 SINGLE PLT, FLYING CARGO, MADE AN ALT OVERSHOOT WITH NCT TRACON.

Narrative: FINAL LEG (MOD-OAK) ON 135 CARGO FLT WITH A FAMILIAR RTE. RADAR VECTORS TO JOIN AIRWAY, CLB AND MAINTAIN 6000 FT. AFTER DEPARTING MOD, HANDED OFF TO NORCAL APCH CTLR AND TOLD TO CLB AND MAINTAIN 5000 FT. I READ BACK 5000 FT AND SET MY ALT REMINDER BUG FROM 6000 FT TO 5000 FT (JUST INDICATES VALUE, NO WARNINGS). WHILE CLBING THROUGH ABOUT 3500-4000 FT, I BEGAN CONCERNING MYSELF WITH THE INEVITABLE APCH INTO OAK. I KNEW THE WX WAS IFR AND I BEGAN PREPARATION TASKS FOR THE APCH (PICKED UP ATIS AND LEAFING THROUGH THE CHARTS IN MY BINDER). I PASSED THROUGH 5000 FT AND CONTINUED TO 6000 FT, THE ORIGINAL ALT. UPON REACHING 6000 FT, THE CTLR GAVE ME A VECTOR FOR TFC AND REMINDED ME THAT I'D BEEN ASSIGNED 5000 FT. I FELT SICK TO MY STOMACH AS I REALIZED MY ERROR. I TURNED TO THE NEW HDG AND TOLD THE CTLR I WAS DSNDING TO 5000 FT IMMEDIATELY. HE AGREED THAT WOULD BE DESIRABLE. THE ALT BUG INDICATED 5000 FT AND I REMEMBERED READING BACK 5000 FT. ABOUT 5 MINS LATER, THE CONFLICTING TFC PASSED AT MY 3 O'CLOCK POS, MAYBE 10 MI AWAY. TFC WAS NO FACTOR, BUT THAT WAS DUE TO THE CTLR'S VIGILANCE AND PRE-EMPTIVE ACTION. THE CTLR ASKED ME IF I'D READ BACK 5000 FT TO HIM. I TOLD HIM, YES I HAD, THE MISTAKE WAS TOTALLY MY FAULT, AND I APOLOGIZED FOR CREATING THE SIT. THE CTLR SAID NOTHING MORE ABOUT IT, HANDED ME OFF TO THE NEXT CTLR, AND THE REST OF THE FLT PASSED WITHOUT INCIDENT. THE LESSONS I'M TAKING AWAY FROM THIS INCIDENT ARE NUMEROUS. YOU MUST CONSTANTLY GUARD AGAINST COMPLACENCY. I WAS COMPLACENT ABOUT MY REGULAR CLRNC, NOT CHALLENGING MY PRESUMPTIONS, AND TAKING THE PHASE OF FLT FOR GRANTED. I GOT AHEAD OF MYSELF AND BECAME PREOCCUPIED WITH MY APCH AND DIDN'T PAY ATTN TO WHERE I WAS AND WHAT I WAS DOING AT THE MOMENT. I NEED TO CHANGE SOME PROCS OR AT LEAST INCORPORATE THINGS MORE EFFECTIVELY. THE ALT BUG WILL BECOME AN ACTIVE PART OF MY SCAN AND NOT JUST USED PASSIVELY FOR REF. I WILL CHALLENGE WHAT I'M DOING MORE AND REMIND MYSELF '1000 FT TO GO.' MOST IMPORTANTLY I NEED TO PUT FIRST THINGS FIRST, NOT GET TOO FAR AHEAD OF MYSELF, AND FOCUS ON THE TASK AT HAND. I NEED TO ASK QUESTIONS AND GUARD AGAINST COMPLACENCY.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.