Altitude deviation. Overshoot on descent.

Attributes
ACN	147242
Time
Date	199006
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zzz
State Reference	US
Altitude	msl bound lower : 34400 msl bound upper : 35000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 14000 flight time type : 2000
ASRS Report	147242
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Requested descent to FL290. Set FL290 in MCP altitude window in anticipation of clearance. Cleared to descend to FL350 from FL370. Put FL350 in FMC cruise page with VNAV engaged. When sluggish descent observed, switched to flch mode. As aircraft went through FL350 in high rate of descent, engaged altitude hold and bottomed out at FL344. Climbed back to FL350. Was on off-course vector for descent. No apparent conflict for ATC.

Original NASA ASRS Text

Title: ALT DEVIATION. OVERSHOOT ON DESCENT.

Narrative: REQUESTED DSNT TO FL290. SET FL290 IN MCP ALT WINDOW IN ANTICIPATION OF CLRNC. CLRED TO DSND TO FL350 FROM FL370. PUT FL350 IN FMC CRUISE PAGE WITH VNAV ENGAGED. WHEN SLUGGISH DSNT OBSERVED, SWITCHED TO FLCH MODE. AS ACFT WENT THROUGH FL350 IN HIGH RATE OF DSNT, ENGAGED ALT HOLD AND BOTTOMED OUT AT FL344. CLBED BACK TO FL350. WAS ON OFF-COURSE VECTOR FOR DSNT. NO APPARENT CONFLICT FOR ATC.

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.