A DC9 crew, arriving dtw via a STAR, turned prematurely, requiring a corrective vector from ATC.

Attributes
ACN	535149
Time
Date	200201
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dtw.airport
State Reference	MI
Altitude	msl single value : 11500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : d21.tracon tower : pit.tower
Operator	common carrier : air carrier
Make Model Name	DC-9 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival star : cetus2
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : instrument pilot : flight engineer pilot : multi engine
Experience	flight time last 90 days : 200 flight time total : 16000 flight time type : 9000
ASRS Report	535149
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	non adherence : clearance non adherence : published procedure other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Upon check-in with dtw approach, clearance given to fly the cetus 2 arrival with a turn to 030 degree heading at gloze. Also cleared to descend from 12000 ft MSL to 11000 ft MSL. I was looking at the arrival chart to confirm DME at gloze. When I looked up I saw that copilot had started turn to 030 degree heading 20 mi early. Before I could correct the situation, ATC provided vectors to correct our mistake.

Original NASA ASRS Text

Title: A DC9 CREW, ARRIVING DTW VIA A STAR, TURNED PREMATURELY, REQUIRING A CORRECTIVE VECTOR FROM ATC.

Narrative: UPON CHK-IN WITH DTW APCH, CLRNC GIVEN TO FLY THE CETUS 2 ARR WITH A TURN TO 030 DEG HDG AT GLOZE. ALSO CLRED TO DSND FROM 12000 FT MSL TO 11000 FT MSL. I WAS LOOKING AT THE ARR CHART TO CONFIRM DME AT GLOZE. WHEN I LOOKED UP I SAW THAT COPLT HAD STARTED TURN TO 030 DEG HDG 20 MI EARLY. BEFORE I COULD CORRECT THE SIT, ATC PROVIDED VECTORS TO CORRECT OUR MISTAKE.

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.