Narrative:

Approach cleared us to descend to 9000'. The aircraft FMS had been configured for landing on runway 29R, radios tuned, runway selected, all systems set up for approach. I was flying and had turned off the flight director, autoplt and automatic throttle. At about 9300 or 9200', approach called to give us a vector heading at fgt--I think it was 040 degrees--and told us to plan for a runway 29L approach. I looked up to check the MCP for proper heading to be taken after fgt and the double-checked the approach plate for frequency and inbound course. I don't remember if I set it. In the meantime, the aircraft had descended to 8700' or so. I stopped descent and was climbing again by about 8550'. I climbed back to 9000'. The problem was my own making: 1) I allowed an outside distraction to interrupt at a critical time. 2) I should have directed the first officer to change radios and set up my instruments. And perhaps most important: 3) I was very fatigued. This was the last day of a 3 day trip. Originally I considered calling the company and not flying the first day. The night before departure after I had gone to sleep we had a local emergency declared with several tornadoes sighted and moving into our town. We took our children into the basement to wait it out. As a result, I was unable to get enough rest that night. I got up at am:15 to leave home for an am:00 departure. In addition, for the next 2 days my wake-up calls were for am:15. I simply could not get enough sleep. I still find it very difficult to consider calling the company to say I am not rested enough to fly the next day. It is difficult to recognize how much fatigue affects my performance, especially when I am fatigued. As an addition comment, the crew desk knew we were having the emergency--I was talking to them about other things. I did mention to them I was concerned about myself, but I didn't take action.

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Original NASA ASRS Text

Title: ALT DEVIATION DURING RADAR VECTORING ON AN ADVANCED COCKPIT ACFT.

Narrative: APCH CLRED US TO DSND TO 9000'. THE ACFT FMS HAD BEEN CONFIGURED FOR LNDG ON RWY 29R, RADIOS TUNED, RWY SELECTED, ALL SYSTEMS SET UP FOR APCH. I WAS FLYING AND HAD TURNED OFF THE FLT DIRECTOR, AUTOPLT AND AUTO THROTTLE. AT ABOUT 9300 OR 9200', APCH CALLED TO GIVE US A VECTOR HDG AT FGT--I THINK IT WAS 040 DEGS--AND TOLD US TO PLAN FOR A RWY 29L APCH. I LOOKED UP TO CHK THE MCP FOR PROPER HDG TO BE TAKEN AFTER FGT AND THE DOUBLE-CHKED THE APCH PLATE FOR FREQ AND INBND COURSE. I DON'T REMEMBER IF I SET IT. IN THE MEANTIME, THE ACFT HAD DSNDED TO 8700' OR SO. I STOPPED DSNT AND WAS CLBING AGAIN BY ABOUT 8550'. I CLBED BACK TO 9000'. THE PROB WAS MY OWN MAKING: 1) I ALLOWED AN OUTSIDE DISTR TO INTERRUPT AT A CRITICAL TIME. 2) I SHOULD HAVE DIRECTED THE F/O TO CHANGE RADIOS AND SET UP MY INSTS. AND PERHAPS MOST IMPORTANT: 3) I WAS VERY FATIGUED. THIS WAS THE LAST DAY OF A 3 DAY TRIP. ORIGINALLY I CONSIDERED CALLING THE COMPANY AND NOT FLYING THE FIRST DAY. THE NIGHT BEFORE DEP AFTER I HAD GONE TO SLEEP WE HAD A LCL EMER DECLARED WITH SEVERAL TORNADOES SIGHTED AND MOVING INTO OUR TOWN. WE TOOK OUR CHILDREN INTO THE BASEMENT TO WAIT IT OUT. AS A RESULT, I WAS UNABLE TO GET ENOUGH REST THAT NIGHT. I GOT UP AT AM:15 TO LEAVE HOME FOR AN AM:00 DEP. IN ADDITION, FOR THE NEXT 2 DAYS MY WAKE-UP CALLS WERE FOR AM:15. I SIMPLY COULD NOT GET ENOUGH SLEEP. I STILL FIND IT VERY DIFFICULT TO CONSIDER CALLING THE COMPANY TO SAY I AM NOT RESTED ENOUGH TO FLY THE NEXT DAY. IT IS DIFFICULT TO RECOGNIZE HOW MUCH FATIGUE AFFECTS MY PERFORMANCE, ESPECIALLY WHEN I AM FATIGUED. AS AN ADDITION COMMENT, THE CREW DESK KNEW WE WERE HAVING THE EMER--I WAS TALKING TO THEM ABOUT OTHER THINGS. I DID MENTION TO THEM I WAS CONCERNED ABOUT MYSELF, BUT I DIDN'T TAKE ACTION.

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.