B737-700 pilot nods off several times during approach.

Attributes
ACN	701255
Time
Date	200606
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : mdw.airport
State Reference	IL
Altitude	msl single value : 3000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	tracon : c90.tracon tower : den.tower
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 200 flight time total : 17000 flight time type : 12000
ASRS Report	701255
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : far other anomaly other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Supplementary
Problem Areas	Flight Crew Human Performance Company
Primary Problem	Flight Crew Human Performance

Narrative:

Was requested by scheduling to operate another flight and that aircraft was to arrive in 1.5 hours. Felt tired but ok and accepted the assignment. Aircraft arrived about 2.5 hours later. Captain had timed out but first officer continued with me. Felt ok at push. Upon descent into mdw I began to feel very fatigued. On final approach I must have nodded off several times. I remember snapping awake several times. There were no major deviations in the approach (I think). I think the term is micro-sleep. Considered giving the aircraft to the first officer but he seemed not much better. Landed uneventfully. Lesson learned: knowing what your future state will be when accepting an assignment is exceedingly difficult as is recognizing the onset of fatigue. I had been up about 19 hours at push but still felt ok.

Original NASA ASRS Text

Title: B737-700 PLT NODS OFF SEVERAL TIMES DURING APCH.

Narrative: WAS REQUESTED BY SCHEDULING TO OPERATE ANOTHER FLT AND THAT ACFT WAS TO ARRIVE IN 1.5 HRS. FELT TIRED BUT OK AND ACCEPTED THE ASSIGNMENT. ACFT ARRIVED ABOUT 2.5 HRS LATER. CAPT HAD TIMED OUT BUT FO CONTINUED WITH ME. FELT OK AT PUSH. UPON DSCNT INTO MDW I BEGAN TO FEEL VERY FATIGUED. ON FINAL APCH I MUST HAVE NODDED OFF SEVERAL TIMES. I REMEMBER SNAPPING AWAKE SEVERAL TIMES. THERE WERE NO MAJOR DEVS IN THE APCH (I THINK). I THINK THE TERM IS MICRO-SLEEP. CONSIDERED GIVING THE ACFT TO THE FO BUT HE SEEMED NOT MUCH BETTER. LANDED UNEVENTFULLY. LESSON LEARNED: KNOWING WHAT YOUR FUTURE STATE WILL BE WHEN ACCEPTING AN ASSIGNMENT IS EXCEEDINGLY DIFFICULT AS IS RECOGNIZING THE ONSET OF FATIGUE. I HAD BEEN UP ABOUT 19 HRS AT PUSH BUT STILL FELT OK.

Data retrieved from NASA's ASRS site as of January 2009 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.