B727 descends below assigned altitude on approach to slc.

Attributes
ACN	438950
Time
Date	199905
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : slc.airport
State Reference	UT
Altitude	msl bound lower : 9600 msl bound upper : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : s56.tracon
Operator	common carrier : air carrier
Make Model Name	B727 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	descent : intermediate altitude
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 3800 flight time type : 1000
ASRS Report	438950
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Slc approach was vectoring us on downwind. They assigned us to descend and maintain 10000 ft. We were setting up for a visual approach looking for traffic to follow on final. We descended through 10000 ft MSL to approximately 9600 ft MSL and corrected back immediately. No conflict with other traffic was created. ATC made no mention of our deviation.

Original NASA ASRS Text

Title: B727 DSNDS BELOW ASSIGNED ALT ON APCH TO SLC.

Narrative: SLC APCH WAS VECTORING US ON DOWNWIND. THEY ASSIGNED US TO DSND AND MAINTAIN 10000 FT. WE WERE SETTING UP FOR A VISUAL APCH LOOKING FOR TFC TO FOLLOW ON FINAL. WE DSNDED THROUGH 10000 FT MSL TO APPROX 9600 FT MSL AND CORRECTED BACK IMMEDIATELY. NO CONFLICT WITH OTHER TFC WAS CREATED. ATC MADE NO MENTION OF OUR DEV.

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.