PA32 pilot allegedly misinterpret a descent clearance causing planned leveloff at wrong altitude.

Attributes
ACN	493080
Time
Date	200011
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : dbq.airport
State Reference	IA
Altitude	msl bound lower : 2500 msl bound upper : 2800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau.artcc tower : dbq.tower
Operator	general aviation : personal
Make Model Name	PA-32 Cherokee Six/Lance/Saratoga
Operating Under FAR Part	Part 91
Flight Phase	descent : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	other
Function	flight crew : single pilot
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 59 flight time total : 3672 flight time type : 350
ASRS Report	493080
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to assigned altitude other
Consequence	faa : reviewed incident with flight crew
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On an IFR trip from arv to dbq airport, I was given a descent clearance by ZAU when about 25 mi from dbq. Center cleared me to descend from 6000 ft MSL to 2000 ft MSL. I clearly heard 2000 ft MSL and acknowledged 'descend from 6000 ft to 2000 ft.' as I was passing through 2500 ft MSL, center told me I was supposed to maintain 2800 ft MSL. I explained that I heard 2000 ft but he said he specified 2800 ft. I immediately started back to 2800 ft. He asked me if I had ground contact, and I said yes. Previously, I had asked for a visual approach as ATIS stated ceilings were 8000 ft with 7 mi. At this point, I was 11 mi from dbq airport with the airport in sight, so I canceled IFR and continued to land VFR. There were no other planes in the area. ZAU said I could continue IFR or cancel IFR as my choice. I canceled and contacted dbq tower. I feel that controllers need to listen to readback of clrncs and advise if not what they intended.

Original NASA ASRS Text

Title: PA32 PLT ALLEGEDLY MISINTERPRET A DSCNT CLRNC CAUSING PLANNED LEVELOFF AT WRONG ALT.

Narrative: ON AN IFR TRIP FROM ARV TO DBQ ARPT, I WAS GIVEN A DSCNT CLRNC BY ZAU WHEN ABOUT 25 MI FROM DBQ. CTR CLRED ME TO DSND FROM 6000 FT MSL TO 2000 FT MSL. I CLRLY HEARD 2000 FT MSL AND ACKNOWLEDGED 'DSND FROM 6000 FT TO 2000 FT.' AS I WAS PASSING THROUGH 2500 FT MSL, CTR TOLD ME I WAS SUPPOSED TO MAINTAIN 2800 FT MSL. I EXPLAINED THAT I HEARD 2000 FT BUT HE SAID HE SPECIFIED 2800 FT. I IMMEDIATELY STARTED BACK TO 2800 FT. HE ASKED ME IF I HAD GND CONTACT, AND I SAID YES. PREVIOUSLY, I HAD ASKED FOR A VISUAL APCH AS ATIS STATED CEILINGS WERE 8000 FT WITH 7 MI. AT THIS POINT, I WAS 11 MI FROM DBQ ARPT WITH THE ARPT IN SIGHT, SO I CANCELED IFR AND CONTINUED TO LAND VFR. THERE WERE NO OTHER PLANES IN THE AREA. ZAU SAID I COULD CONTINUE IFR OR CANCEL IFR AS MY CHOICE. I CANCELED AND CONTACTED DBQ TWR. I FEEL THAT CTLRS NEED TO LISTEN TO READBACK OF CLRNCS AND ADVISE IF NOT WHAT THEY INTENDED.

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.