B737-700 crew had runway incursion at MMMX.

Attributes
ACN	513338
Time
Date	200106
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mmmx.airport
State Reference	FO
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
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 : atp
ASRS Report	513338
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : multi engine pilot : commercial
ASRS Report	513337
Events
Anomaly	incursion : runway non adherence : far non adherence : published procedure non adherence : company policies non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued alert controller : issued new clearance other
Consequence	other
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Runway incursion. Holding short runway 5L at mex. Tower cleared us into position and hold runway 5L. We replied position and hold runway 5L. Then we requested runway 5R. Tower cleared us to taxi and hold short runway 5R. While taxiing to runway 5R I was explaining to the first officer the reason for using runway 5R. I taxied onto position on runway 5R. Tower informed us of my mistake and we cleared runway 5R without incident. Subsequent takeoff was uneventful.

Original NASA ASRS Text

Title: B737-700 CREW HAD RWY INCURSION AT MMMX.

Narrative: RWY INCURSION. HOLDING SHORT RWY 5L AT MEX. TWR CLRED US INTO POS AND HOLD RWY 5L. WE REPLIED POS AND HOLD RWY 5L. THEN WE REQUESTED RWY 5R. TWR CLRED US TO TAXI AND HOLD SHORT RWY 5R. WHILE TAXIING TO RWY 5R I WAS EXPLAINING TO THE FO THE REASON FOR USING RWY 5R. I TAXIED ONTO POS ON RWY 5R. TWR INFORMED US OF MY MISTAKE AND WE CLRED RWY 5R WITHOUT INCIDENT. SUBSEQUENT TKOF WAS UNEVENTFUL.

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.