Pilot instructed by ATC to descend to 6000 ft and incorrectly descends to 3000 ft.

Attributes
ACN	406670
Time
Date	199806
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : tpa
State Reference	FL
Altitude	msl bound lower : 3000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : tpa
Operator	general aviation : corporate
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : cfi pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 85 flight time total : 23000 flight time type : 5000
ASRS Report	406670
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
Independent Detector	other controllera
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Approach control cleared me to descend to 6000 ft. I thought he said 3000 ft and read back 3000 ft and descended to 3000 ft. It was called to my attention that I was at the wrong altitude. Just a misunderstanding on my part.

Original NASA ASRS Text

Title: PLT INSTRUCTED BY ATC TO DSND TO 6000 FT AND INCORRECTLY DSNDS TO 3000 FT.

Narrative: APCH CTL CLRED ME TO DSND TO 6000 FT. I THOUGHT HE SAID 3000 FT AND READ BACK 3000 FT AND DSNDED TO 3000 FT. IT WAS CALLED TO MY ATTN THAT I WAS AT THE WRONG ALT. JUST A MISUNDERSTANDING ON MY PART.

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.