Flight crew of an medium large transport overshot altitude on descent.

Attributes
ACN	299570
Time
Date	199503
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : bos
State Reference	MA
Altitude	msl bound lower : 12800 msl bound upper : 13000
Environment
Flight Conditions	IMC
Light	Dusk
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	other
Route In Use	enroute airway : zbw
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 255 flight time total : 27200 flight time type : 2500
ASRS Report	299570
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	aircraft equipment other aircraft equipment : unspecified 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:

We were in a holding pattern at 14000 ft and were cleared to descend to 13000 ft with aircraft on autoplt. The autoplt capture feature failed to capture altitude and we descended to 12800 ft before the first officer disconnected the autoplt and returned to 13000 ft. At the time this occurred I was in contact with the boston station updating our ETA. From now on I will not be on radio while in climb or descent, only when in level flight.

Original NASA ASRS Text

Title: FLT CREW OF AN MLG OVERSHOT ALT ON DSCNT.

Narrative: WE WERE IN A HOLDING PATTERN AT 14000 FT AND WERE CLRED TO DSND TO 13000 FT WITH ACFT ON AUTOPLT. THE AUTOPLT CAPTURE FEATURE FAILED TO CAPTURE ALT AND WE DSNDED TO 12800 FT BEFORE THE FO DISCONNECTED THE AUTOPLT AND RETURNED TO 13000 FT. AT THE TIME THIS OCCURRED I WAS IN CONTACT WITH THE BOSTON STATION UPDATING OUR ETA. FROM NOW ON I WILL NOT BE ON RADIO WHILE IN CLB OR DSCNT, ONLY WHEN IN LEVEL FLT.

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.