An small transport frtr left its assigned altitude without clearance.

Attributes
ACN	266719
Time
Date	199403
Day	Tue
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : stl
State Reference	MO
Altitude	msl bound lower : 4000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : stl tracon : den
Operator	common carrier : air taxi
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air taxi
Function	flight crew : single pilot
Qualification	pilot : atp
Experience	flight time last 90 days : 120 flight time total : 3500 flight time type : 300
ASRS Report	266719
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Inbound to stl, ZKC cleared us for a descent from 9000 ft to 5000 ft at pilot discretion. During descent, handed off to stl TRACON repeated that I was descending to 5000 ft. About 20 mi out still in descent to 5000 ft, report airport in sight. I fly this run every night, and usually get cleared for visual as soon as I report airport, or at least get lower altitude. Got distracted by reporting ETA and related information to company dispatch and also chatting on air-to-air frequency with another aircraft. Thought I'd heard ATC report 'cleared for the visual,' but that might have been for other aircraft. At 4200 ft, ATC said, 'I thought you were cleared to 5000 ft?' I asked 'am I cleared for the visual,' to which he replied, 'no, not yet.' I was complacent, thinking clrncs would work like every other night and not paying as much attention as I should have. Should not have assumed I was cleared for the visual.

Original NASA ASRS Text

Title: AN SMT FRTR LEFT ITS ASSIGNED ALT WITHOUT CLRNC.

Narrative: INBOUND TO STL, ZKC CLRED US FOR A DSCNT FROM 9000 FT TO 5000 FT AT PLT DISCRETION. DURING DSCNT, HANDED OFF TO STL TRACON REPEATED THAT I WAS DSNDING TO 5000 FT. ABOUT 20 MI OUT STILL IN DSCNT TO 5000 FT, RPT ARPT IN SIGHT. I FLY THIS RUN EVERY NIGHT, AND USUALLY GET CLRED FOR VISUAL AS SOON AS I RPT ARPT, OR AT LEAST GET LOWER ALT. GOT DISTRACTED BY RPTING ETA AND RELATED INFO TO COMPANY DISPATCH AND ALSO CHATTING ON AIR-TO-AIR FREQ WITH ANOTHER ACFT. THOUGHT I'D HEARD ATC RPT 'CLRED FOR THE VISUAL,' BUT THAT MIGHT HAVE BEEN FOR OTHER ACFT. AT 4200 FT, ATC SAID, 'I THOUGHT YOU WERE CLRED TO 5000 FT?' I ASKED 'AM I CLRED FOR THE VISUAL,' TO WHICH HE REPLIED, 'NO, NOT YET.' I WAS COMPLACENT, THINKING CLRNCS WOULD WORK LIKE EVERY OTHER NIGHT AND NOT PAYING AS MUCH ATTN AS I SHOULD HAVE. SHOULD NOT HAVE ASSUMED I WAS CLRED FOR THE VISUAL.

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.