A C421 pilot commenced a takeoff roll on the wrong runway at cos.

Attributes
ACN	484540
Time
Date	200009
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : cos.airport
State Reference	CO
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : l15.tower
Operator	common carrier : charter
Make Model Name	Golden Eagle 421
Operating Under FAR Part	Part 91
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : charter
Function	flight crew : single pilot
Qualification	pilot : multi engine pilot : instrument pilot : commercial pilot : cfi
Experience	flight time last 90 days : 100 flight time total : 2000
ASRS Report	484540
Person 2
Affiliation	company : charter
Function	observation : passenger
Events
Anomaly	incursion : runway non adherence : clearance non adherence : far non adherence : published procedure
Independent Detector	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:

I was cleared to take off on runway 17R at cos and started to take off on runway 12. Rolled 100 ft and asked tower to return for takeoff on runway 17R. Contributing factors were situational awareness and poor runway marking. I discovered, on takeoff roll, when I saw runway 12. Next time, I will not be in such a hurry. Being tired and fatigued also were factors. Second passenger trip ever.

Original NASA ASRS Text

Title: A C421 PLT COMMENCED A TKOF ROLL ON THE WRONG RWY AT COS.

Narrative: I WAS CLRED TO TAKE OFF ON RWY 17R AT COS AND STARTED TO TAKE OFF ON RWY 12. ROLLED 100 FT AND ASKED TWR TO RETURN FOR TKOF ON RWY 17R. CONTRIBUTING FACTORS WERE SITUATIONAL AWARENESS AND POOR RWY MARKING. I DISCOVERED, ON TKOF ROLL, WHEN I SAW RWY 12. NEXT TIME, I WILL NOT BE IN SUCH A HURRY. BEING TIRED AND FATIGUED ALSO WERE FACTORS. SECOND PAX TRIP EVER.

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.