Track deviation when clearance is confused at the end of an all night 11 hour duty day.

Attributes
ACN	480840
Time
Date	200007
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : cvg.airport
State Reference	KY
Altitude	msl single value : 6000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Regional Jet CL65, Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : multi engine pilot : instrument pilot : cfi
Experience	flight time last 90 days : 200 flight time total : 3000 flight time type : 500
ASRS Report	480840
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	inflight encounter : weather non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllerb other flight crewa
Resolutory Action	controller : issued new clearance
Supplementary
Problem Areas	Flight Crew Human Performance Company
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Crew was being vectored by cvg approach and the first officer responded verbally to cvg approach to make a right turn to 320 degrees (downwind for cvg runway 18L). The captain was flying and thought the instruction was to turn to heading 230 degrees. The PNF first officer believed the turn to the left was just a momentary turn to avoid a convective buildup before turning as instructed. By the time the first officer realized the captain had misunderstood the vector and was in the process of discussing the wrong turn with the captain, ATC called us and redirected us for our sequence into cvg. The approach checklist was being conducted during the wrong turn. The crew had been on duty since XA40 the previous day (over 11 hours with little rest). This is a typical example of how fatigue can cause drastically deteriorated performance in even the simplest of flying tasks. I believe the FAA should re-evaluate rest rules for continuous duty, 'back side of the clock' operations. I have seen this type of situation occur many times for the same reasons: continuous duty, reduced rest, or inadequate rest.

Original NASA ASRS Text

Title: TRACK DEV WHEN CLRNC IS CONFUSED AT THE END OF AN ALL NIGHT 11 HR DUTY DAY.

Narrative: CREW WAS BEING VECTORED BY CVG APCH AND THE FO RESPONDED VERBALLY TO CVG APCH TO MAKE A R TURN TO 320 DEGS (DOWNWIND FOR CVG RWY 18L). THE CAPT WAS FLYING AND THOUGHT THE INSTRUCTION WAS TO TURN TO HDG 230 DEGS. THE PNF FO BELIEVED THE TURN TO THE L WAS JUST A MOMENTARY TURN TO AVOID A CONVECTIVE BUILDUP BEFORE TURNING AS INSTRUCTED. BY THE TIME THE FO REALIZED THE CAPT HAD MISUNDERSTOOD THE VECTOR AND WAS IN THE PROCESS OF DISCUSSING THE WRONG TURN WITH THE CAPT, ATC CALLED US AND REDIRECTED US FOR OUR SEQUENCE INTO CVG. THE APCH CHKLIST WAS BEING CONDUCTED DURING THE WRONG TURN. THE CREW HAD BEEN ON DUTY SINCE XA40 THE PREVIOUS DAY (OVER 11 HRS WITH LITTLE REST). THIS IS A TYPICAL EXAMPLE OF HOW FATIGUE CAN CAUSE DRASTICALLY DETERIORATED PERFORMANCE IN EVEN THE SIMPLEST OF FLYING TASKS. I BELIEVE THE FAA SHOULD RE-EVALUATE REST RULES FOR CONTINUOUS DUTY, 'BACK SIDE OF THE CLOCK' OPS. I HAVE SEEN THIS TYPE OF SIT OCCUR MANY TIMES FOR THE SAME REASONS: CONTINUOUS DUTY, REDUCED REST, OR INADEQUATE REST.

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.