Pilot of small aircraft on descent misinterprets his clearance and descends below assigned altitude.

Attributes
ACN	396790
Time
Date	199803
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : acy
State Reference	NJ
Altitude	msl bound lower : 3400 msl bound upper : 4000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : acy
Operator	general aviation : personal
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : single pilot
Qualification	pilot : instrument pilot : cfi pilot : commercial
Experience	flight time last 90 days : 50 flight time total : 2850 flight time type : 2350
ASRS Report	396790
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

About 40 mi nne of acy (my destination airport) I was cleared to descend from 6000 ft MSL to 4000 ft MSL. I was also told to expect landing on runway 13 with a left base entry. I mistook this to mean that I should descend for landing and continued my descent to 3400 ft. At this time the controller requested my altitude and cleared me to descend to 3000 ft. There was no other traffic in the area at this time to conflict with.

Original NASA ASRS Text

Title: PLT OF SMA ON DSCNT MISINTERPRETS HIS CLRNC AND DSNDS BELOW ASSIGNED ALT.

Narrative: ABOUT 40 MI NNE OF ACY (MY DEST ARPT) I WAS CLRED TO DSND FROM 6000 FT MSL TO 4000 FT MSL. I WAS ALSO TOLD TO EXPECT LNDG ON RWY 13 WITH A L BASE ENTRY. I MISTOOK THIS TO MEAN THAT I SHOULD DSND FOR LNDG AND CONTINUED MY DSCNT TO 3400 FT. AT THIS TIME THE CTLR REQUESTED MY ALT AND CLRED ME TO DSND TO 3000 FT. THERE WAS NO OTHER TFC IN THE AREA AT THIS TIME TO CONFLICT WITH.

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.