Air carrier took wrong clearance and climbed 2000' without authorization.

Attributes
ACN	84793
Time
Date	198803
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : etx airport : abe
State Reference	PA
Altitude	msl bound lower : 4000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : abe tracon : har
Operator	common carrier : air carrier
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Flight Phase	climbout : intermediate altitude cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 3800 flight time type : 35
ASRS Report	84793
Person 2
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
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:

On departure from allentown PA to bwi we were talking to abe departure frequency 124.45 and heard a frequency change for our flight to harrisburg approach frequency 126.45 and an altitude change from 4000' to 6000'. Upon contacting harrisburg approach we were informed that we had made our frequency change in error. So we returned to our former frequency (abe 124.45). When we reported back on with allentown he informed us he had not issued an altitude change. We asked if our altitude change had caused a conflict and he replied 'no not really'. From this experience I learned to monitor ATC instructions more carefully and not automatically assume that instructions are for our flight when they normally should occur.

Original NASA ASRS Text

Title: ACR TOOK WRONG CLRNC AND CLIMBED 2000' WITHOUT AUTHORIZATION.

Narrative: ON DEPARTURE FROM ALLENTOWN PA TO BWI WE WERE TALKING TO ABE DEP FREQ 124.45 AND HEARD A FREQ CHANGE FOR OUR FLT TO HARRISBURG APCH FREQ 126.45 AND AN ALT CHANGE FROM 4000' TO 6000'. UPON CONTACTING HARRISBURG APCH WE WERE INFORMED THAT WE HAD MADE OUR FREQ CHANGE IN ERROR. SO WE RETURNED TO OUR FORMER FREQ (ABE 124.45). WHEN WE REPORTED BACK ON WITH ALLENTOWN HE INFORMED US HE HAD NOT ISSUED AN ALT CHANGE. WE ASKED IF OUR ALT CHANGE HAD CAUSED A CONFLICT AND HE REPLIED 'NO NOT REALLY'. FROM THIS EXPERIENCE I LEARNED TO MONITOR ATC INSTRUCTIONS MORE CAREFULLY AND NOT AUTOMATICALLY ASSUME THAT INSTRUCTIONS ARE FOR OUR FLT WHEN THEY NORMALLY SHOULD OCCUR.

Data retrieved from NASA's ASRS site as of August 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.