B757 descended below its assigned altitude of 7000 ft.

Attributes
ACN	352509
Time
Date	199611
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : sli airport : sna
State Reference	CA
Altitude	msl bound lower : 6500 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : sna
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	352509
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
ASRS Report	352510
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Flying the east side 1 STAR to sna. Received clearance to cross kayoh at 7000 ft (1000 ft lower than expected crossing altitude on STAR). I started to descend to 6000 ft after kayoh instead of maintaining 7000 ft. At approximately between 6500 ft and 7000 ft, realized mistake -- at the same time clearance was received for visual approach. No traffic conflict existed. Should have checked crossing altitudes more carefully on STAR approach plate.

Original NASA ASRS Text

Title: B757 DSNDED BELOW ITS ASSIGNED ALT OF 7000 FT.

Narrative: FLYING THE EAST SIDE 1 STAR TO SNA. RECEIVED CLRNC TO CROSS KAYOH AT 7000 FT (1000 FT LOWER THAN EXPECTED XING ALT ON STAR). I STARTED TO DSND TO 6000 FT AFTER KAYOH INSTEAD OF MAINTAINING 7000 FT. AT APPROX BTWN 6500 FT AND 7000 FT, REALIZED MISTAKE -- AT THE SAME TIME CLRNC WAS RECEIVED FOR VISUAL APCH. NO TFC CONFLICT EXISTED. SHOULD HAVE CHKED XING ALTS MORE CAREFULLY ON STAR APCH PLATE.

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.