Cleared for takeoff, a pilot taxies onto the runway at a point short of full length.

Attributes
ACN	492115
Time
Date	200011
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : sju.airport
State Reference	PR
Altitude	agl single value : 0
Environment
Flight Conditions	IMC
Weather Elements	Rain
Light	Night
Aircraft 1
Controlling Facilities	tower : sju.tower
Operator	common carrier : air carrier
Make Model Name	ATR 42
Operating Under FAR Part	Part 121
Flight Phase	ground : taxi
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : cfi pilot : atp pilot : multi engine
Experience	flight time last 90 days : 120 flight time total : 3800 flight time type : 2000
ASRS Report	492115
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : multi engine pilot : commercial
Events
Anomaly	incursion : taxiway non adherence : company policies non adherence : published procedure non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	other
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

After waiting for more than 1 hour due to a mechanical problem with our aircraft, we departed the gate area in a new aircraft for runway 8. We were cleared for departure from runway 8 and were performing our before takeoff checks when I noticed that I had inadvertently taken runway 8 from taxiway Y rather than at the end at taxiway Z. No other traffic was at the runway or near any adjoining taxiway, or on final for either runway 8 or runway 10 at the time of clearance. As I immediately noticed the situation, I asked the tower for clearance from taxiway Y and they approved, unaware of the situation. The WX, delay, and fatigue all played a part in the mistake. One mistake which was indeed an eye-opener for this captain with 2000 hours in the aircraft at that particular airport, the most familiar one of all being the base of our operation. The first officer was completely unaware as well, himself very tired from the long wait due to the mechanical that evening. In the future, I will most certainly be more careful at night, and especially when tired.

Original NASA ASRS Text

Title: CLRED FOR TKOF, A PLT TAXIES ONTO THE RWY AT A POINT SHORT OF FULL LENGTH.

Narrative: AFTER WAITING FOR MORE THAN 1 HR DUE TO A MECHANICAL PROB WITH OUR ACFT, WE DEPARTED THE GATE AREA IN A NEW ACFT FOR RWY 8. WE WERE CLRED FOR DEP FROM RWY 8 AND WERE PERFORMING OUR BEFORE TKOF CHKS WHEN I NOTICED THAT I HAD INADVERTENTLY TAKEN RWY 8 FROM TXWY Y RATHER THAN AT THE END AT TXWY Z. NO OTHER TFC WAS AT THE RWY OR NEAR ANY ADJOINING TXWY, OR ON FINAL FOR EITHER RWY 8 OR RWY 10 AT THE TIME OF CLRNC. AS I IMMEDIATELY NOTICED THE SIT, I ASKED THE TWR FOR CLRNC FROM TXWY Y AND THEY APPROVED, UNAWARE OF THE SIT. THE WX, DELAY, AND FATIGUE ALL PLAYED A PART IN THE MISTAKE. ONE MISTAKE WHICH WAS INDEED AN EYE-OPENER FOR THIS CAPT WITH 2000 HRS IN THE ACFT AT THAT PARTICULAR ARPT, THE MOST FAMILIAR ONE OF ALL BEING THE BASE OF OUR OP. THE FO WAS COMPLETELY UNAWARE AS WELL, HIMSELF VERY TIRED FROM THE LONG WAIT DUE TO THE MECHANICAL THAT EVENING. IN THE FUTURE, I WILL MOST CERTAINLY BE MORE CAREFUL AT NIGHT, AND ESPECIALLY WHEN TIRED.

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.