An air carrier jet flight crew flying 160000 pound jet near slc fails to level at assigned altitude.

Attributes
ACN	434654
Time
Date	199904
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : slc.vor
State Reference	UT
Altitude	msl bound lower : 14750 msl bound upper : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : s56.tracon
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine
Experience	flight time last 90 days : 200 flight time total : 16000 flight time type : 5000
ASRS Report	434654
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : atp pilot : multi engine
Experience	flight time last 90 days : 190 flight time total : 6000 flight time type : 1400
ASRS Report	434340
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued alert flight crew : returned to assigned airspace flight crew : overrode automation
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were on descent to approach at slc. Clearance had been given to descend from 17000 ft to 15000 ft. Aircraft was being flown on autoplt in vertical speed mode. At 15000 ft, autoplt failed to capture the altitude. At 14750 ft, aircraft was manually flown back to 15000 ft just as approach controller reported that aircraft was low. It is not believed that a conflict occurred.

Original NASA ASRS Text

Title: AN ACR JET FLC FLYING 160000 LB JET NEAR SLC FAILS TO LEVEL AT ASSIGNED ALT.

Narrative: WE WERE ON DSCNT TO APCH AT SLC. CLRNC HAD BEEN GIVEN TO DSND FROM 17000 FT TO 15000 FT. ACFT WAS BEING FLOWN ON AUTOPLT IN VERT SPD MODE. AT 15000 FT, AUTOPLT FAILED TO CAPTURE THE ALT. AT 14750 FT, ACFT WAS MANUALLY FLOWN BACK TO 15000 FT JUST AS APCH CTLR RPTED THAT ACFT WAS LOW. IT IS NOT BELIEVED THAT A CONFLICT OCCURRED.

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.