Small transport flight crew began climbing without an ATC clearance.

Attributes
ACN	348950
Time
Date	199610
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : sjt
State Reference	TX
Altitude	msl bound lower : 12000 msl bound upper : 12500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 135
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 270 flight time total : 4000 flight time type : 2500
ASRS Report	348950
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : far
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

I was PF, first officer called center and asked for FL210. We were previously cleared from maf departure to 12000 ft. I heard a 'roger,' but it was not for our aircraft. Center was swamped working several frequencys. Our initial call was blocked. We were not cleared to higher. I noticed that fact at 12500 ft. The aircraft was then descended to 12000 ft and never heard anything about it.

Original NASA ASRS Text

Title: SMT FLC BEGAN CLBING WITHOUT AN ATC CLRNC.

Narrative: I WAS PF, FO CALLED CTR AND ASKED FOR FL210. WE WERE PREVIOUSLY CLRED FROM MAF DEP TO 12000 FT. I HEARD A 'ROGER,' BUT IT WAS NOT FOR OUR ACFT. CTR WAS SWAMPED WORKING SEVERAL FREQS. OUR INITIAL CALL WAS BLOCKED. WE WERE NOT CLRED TO HIGHER. I NOTICED THAT FACT AT 12500 FT. THE ACFT WAS THEN DSNDED TO 12000 FT AND NEVER HEARD ANYTHING ABOUT IT.

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.