Altitude deviation from assigned on initial approach segment.

Attributes
ACN	109544
Time
Date	198904
Day	Fri
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : bhm
State Reference	AL
Altitude	msl bound lower : 2100 msl bound upper : 2500
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bhm
Operator	common carrier : air taxi
Make Model Name	Small Transport
Flight Phase	cruise other cruise other descent : approach
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument pilot : cfi
Experience	flight time last 90 days : 250 flight time total : 2200 flight time type : 100
ASRS Report	109544
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While being vectored for the localizer 23 approach at bhm, the controller issued a turn and an altitude to maintain (which apparently was 2500' MSL), and at the same time, some other complex instructions about some traffic that would be departing runway 5, opp direction. I was on the last leg of an 8 hour duty day and had also been west/O sleep for 18 hours. I mistakenly thought the controller told me to descend to 2000' MSL. I was on the final vector to intercept the final and had looked at the approach chart and it showed 2000' MSL as the final approach fix altitude. I also thought 2000' MSL was the altitude the approach controller had issued. (I apparently was wrong, it was 2500' MSL). After passing 2100' MSL the controller told me my assigned altitude was 2500'. I immediately climbed back to 2500'. I blame the cause of this deviation on the fact that I had been awake for some time and also the fact that the altitude was different from what was shown on the chart which I had been used to.

Original NASA ASRS Text

Title: ALT DEVIATION FROM ASSIGNED ON INITIAL APCH SEGMENT.

Narrative: WHILE BEING VECTORED FOR THE LOC 23 APCH AT BHM, THE CTLR ISSUED A TURN AND AN ALT TO MAINTAIN (WHICH APPARENTLY WAS 2500' MSL), AND AT THE SAME TIME, SOME OTHER COMPLEX INSTRUCTIONS ABOUT SOME TFC THAT WOULD BE DEPARTING RWY 5, OPP DIRECTION. I WAS ON THE LAST LEG OF AN 8 HR DUTY DAY AND HAD ALSO BEEN W/O SLEEP FOR 18 HRS. I MISTAKENLY THOUGHT THE CTLR TOLD ME TO DSND TO 2000' MSL. I WAS ON THE FINAL VECTOR TO INTERCEPT THE FINAL AND HAD LOOKED AT THE APCH CHART AND IT SHOWED 2000' MSL AS THE FINAL APCH FIX ALT. I ALSO THOUGHT 2000' MSL WAS THE ALT THE APCH CTLR HAD ISSUED. (I APPARENTLY WAS WRONG, IT WAS 2500' MSL). AFTER PASSING 2100' MSL THE CTLR TOLD ME MY ASSIGNED ALT WAS 2500'. I IMMEDIATELY CLBED BACK TO 2500'. I BLAME THE CAUSE OF THIS DEVIATION ON THE FACT THAT I HAD BEEN AWAKE FOR SOME TIME AND ALSO THE FACT THAT THE ALT WAS DIFFERENT FROM WHAT WAS SHOWN ON THE CHART WHICH I HAD BEEN USED TO.

Data retrieved from NASA's ASRS site as of August 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.