B757 captain descends early on VOR approach at mex.

Attributes
ACN	439740
Time
Date	199906
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : smo.vor
State Reference	FO
Altitude	msl bound lower : 9000 msl bound upper : 9500
Environment
Flight Conditions	Mixed
Weather Elements	Thunderstorm
Light	Night
Aircraft 1
Controlling Facilities	tracon : mmmx.tracon
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	approach : instrument non precision
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	439740
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : multi engine pilot : instrument
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : published procedure non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to original clearance
Supplementary
Problem Areas	Flight Crew Human Performance Chart Or Publication
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was the PF and we had been cleared for the VOR runway 5R approach. I deviated around WX at smo and intercepted the 160 degree radial. Even though I had briefed 9700 ft after smo until the 248 degree radial of mex, I knew we had to start our descent and hurriedly glanced at the chart and called for 8800 ft and started descending. At this time we were VFR and were looking for the runway out of about 9500 ft. I realized my error and stopped the descent until the 248 degree radial and continued with the approach and landing.

Original NASA ASRS Text

Title: B757 CAPT DSNDS EARLY ON VOR APCH AT MEX.

Narrative: I WAS THE PF AND WE HAD BEEN CLRED FOR THE VOR RWY 5R APCH. I DEVIATED AROUND WX AT SMO AND INTERCEPTED THE 160 DEG RADIAL. EVEN THOUGH I HAD BRIEFED 9700 FT AFTER SMO UNTIL THE 248 DEG RADIAL OF MEX, I KNEW WE HAD TO START OUR DSCNT AND HURRIEDLY GLANCED AT THE CHART AND CALLED FOR 8800 FT AND STARTED DSNDING. AT THIS TIME WE WERE VFR AND WERE LOOKING FOR THE RWY OUT OF ABOUT 9500 FT. I REALIZED MY ERROR AND STOPPED THE DSCNT UNTIL THE 248 DEG RADIAL AND CONTINUED WITH THE APCH AND LNDG.

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.