An SB340 climbed above altitude prior to starting descent near mlc.

Attributes
ACN	436740
Time
Date	199905
Day	Tue
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : mlc.vortac
State Reference	OK
Altitude	msl single value : 23000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zfw.artcc
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Operating Under FAR Part	Part 121
Navigation In Use	other vortac
Flight Phase	cruise : enroute altitude change
Route In Use	enroute other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 2400 flight time type : 800
ASRS Report	436741
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 13000 flight time type : 2000
ASRS Report	436740
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : returned to assigned airspace
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

As we were reaching top of climb, ATC called and assigned lower altitude, pilot's discretion. Since altitude selector was moved before altitude lock took place, aircraft continued to climb slowly. Altitude alert occurred as ATC called. We had already begun our descent, and ATC said 'no problem.'

Original NASA ASRS Text

Title: AN SB340 CLBED ABOVE ALT PRIOR TO STARTING DSCNT NEAR MLC.

Narrative: AS WE WERE REACHING TOP OF CLB, ATC CALLED AND ASSIGNED LOWER ALT, PLT'S DISCRETION. SINCE ALT SELECTOR WAS MOVED BEFORE ALT LOCK TOOK PLACE, ACFT CONTINUED TO CLB SLOWLY. ALT ALERT OCCURRED AS ATC CALLED. WE HAD ALREADY BEGUN OUR DSCNT, AND ATC SAID 'NO PROB.'

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.