An small transport pilot descends below assigned altitude.

Attributes
ACN	447080
Time
Date	199908
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mfi.airport
State Reference	WI
Altitude	msl bound lower : 5000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zmp.artcc
Operator	common carrier : charter
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Operating Under FAR Part	Part 135
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : charter
Function	flight crew : single pilot oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 100 flight time total : 4000
ASRS Report	447080
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Pilot cleared to descend from 10000 ft to 6000 ft. Inadvertently continued descent while trying to cancel IFR flight plan. Controller was extremely busy and did not respond to first 3 attempts to cancel.

Original NASA ASRS Text

Title: AN SMT PLT DSNDS BELOW ASSIGNED ALT.

Narrative: PLT CLRED TO DSND FROM 10000 FT TO 6000 FT. INADVERTENTLY CONTINUED DSCNT WHILE TRYING TO CANCEL IFR FLT PLAN. CTLR WAS EXTREMELY BUSY AND DID NOT RESPOND TO FIRST 3 ATTEMPTS TO CANCEL.

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.