B727 crew went 400 ft below leveloff altitude.

Attributes
ACN	410230
Time
Date	199807
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : mci
State Reference	MO
Altitude	msl bound lower : 10600 msl bound upper : 11000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zkc tower : ord
Operator	common carrier : air carrier
Make Model Name	B727-200
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	approach : visual arrival other enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	410230
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
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:

Descending to 11000 ft. While deviating around WX, descended to 10600 ft before returning to 11000 ft. Should have given aircraft to first officer while I was picking deviation route.

Original NASA ASRS Text

Title: B727 CREW WENT 400 FT BELOW LEVELOFF ALT.

Narrative: DSNDING TO 11000 FT. WHILE DEVIATING AROUND WX, DSNDED TO 10600 FT BEFORE RETURNING TO 11000 FT. SHOULD HAVE GIVEN ACFT TO FO WHILE I WAS PICKING DEV RTE.

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.