A DC8 flight crew misinterprets tower communication to be a clearance for takeoff.

Attributes
ACN	576889
Time
Date	200303
Day	Wed
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : sdf.airport
State Reference	KY
Altitude	agl single value : 0
Environment
Flight Conditions	Marginal
Light	Night
Aircraft 1
Controlling Facilities	tower : btv.tower
Operator	common carrier : air carrier
Make Model Name	DC-8 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 87 flight time total : 13000 flight time type : 8000
ASRS Report	576889
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 60 flight time total : 6000 flight time type : 3000
ASRS Report	577261
Events
Anomaly	incursion : runway non adherence : clearance other anomaly other
Independent Detector	other controllera
Resolutory Action	controller : issued advisory
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:

We were taxiing to the departure end of the runway, about 20 yds prior to stopping. The tower calls us and said you're clear to atl (atl was destination). We took that clearance as a clearance to take off. We took off and during the climb out, the tower said that he had not cleared us for departure. About 1 out of 4 flts, the tower will clear us like this. The tower clearance should have been 'aircraft so and so, cleared to atl direct and taxi into position and hold' or amend clearance to read 'direct atl.'

Original NASA ASRS Text

Title: A DC8 FLT CREW MISINTERPRETS TWR COM TO BE A CLRNC FOR TKOF.

Narrative: WE WERE TAXIING TO THE DEP END OF THE RWY, ABOUT 20 YDS PRIOR TO STOPPING. THE TWR CALLS US AND SAID YOU'RE CLR TO ATL (ATL WAS DEST). WE TOOK THAT CLRNC AS A CLRNC TO TAKE OFF. WE TOOK OFF AND DURING THE CLBOUT, THE TWR SAID THAT HE HAD NOT CLRED US FOR DEP. ABOUT 1 OUT OF 4 FLTS, THE TWR WILL CLR US LIKE THIS. THE TWR CLRNC SHOULD HAVE BEEN 'ACFT SO AND SO, CLRED TO ATL DIRECT AND TAXI INTO POS AND HOLD' OR AMEND CLRNC TO READ 'DIRECT ATL.'

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.