Reporter flight took off without ATC clearance.

Attributes
ACN	111661
Time
Date	198905
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : avp
State Reference	PA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	climbout : takeoff
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp
Experience	flight time last 90 days : 240 flight time total : 3700 flight time type : 240
ASRS Report	111661
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	incursion : runway non adherence : required legal separation non adherence : clearance
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were taxiing for runway 04 at avp. After approaching the hold line I advised the first officer to advise tower we were ready for takeoff. We then were advised to taxi into position and hold. I then taxied the aircraft to the end of the runway as we went through our checklist and the first officer called for the final 2 items, and I told him to perform the items and he had the aircraft. We then proceeded to start our takeoff roll and the first officer advised an aircraft was taxiing across our runway on an intersecting runway and inquired whether we had received a clearance for takeoff. We continued the takeoff and no evasive action was necessary. At approximately 400' AGL the tower instructed us no clearance was issued. We both thought a clearance had been issued and informed the tower we must have misunderstood his instructions. He then told us to contact departure. This was the start of the fifth leg for us that day. We both didn't have anything to eat since starting the work day. This could be a contributing factor since our schedule is normally very tight even when running on time. We should have verified with the tower when the confusion arose. The other thing is to avoid the rut or routine that traps you into these type of situations.

Original NASA ASRS Text

Title: REPORTER FLT TOOK OFF WITHOUT ATC CLRNC.

Narrative: WE WERE TAXIING FOR RWY 04 AT AVP. AFTER APCHING THE HOLD LINE I ADVISED THE F/O TO ADVISE TWR WE WERE READY FOR TKOF. WE THEN WERE ADVISED TO TAXI INTO POS AND HOLD. I THEN TAXIED THE ACFT TO THE END OF THE RWY AS WE WENT THROUGH OUR CHKLIST AND THE F/O CALLED FOR THE FINAL 2 ITEMS, AND I TOLD HIM TO PERFORM THE ITEMS AND HE HAD THE ACFT. WE THEN PROCEEDED TO START OUR TKOF ROLL AND THE F/O ADVISED AN ACFT WAS TAXIING ACROSS OUR RWY ON AN INTERSECTING RWY AND INQUIRED WHETHER WE HAD RECEIVED A CLRNC FOR TKOF. WE CONTINUED THE TKOF AND NO EVASIVE ACTION WAS NECESSARY. AT APPROX 400' AGL THE TWR INSTRUCTED US NO CLRNC WAS ISSUED. WE BOTH THOUGHT A CLRNC HAD BEEN ISSUED AND INFORMED THE TWR WE MUST HAVE MISUNDERSTOOD HIS INSTRUCTIONS. HE THEN TOLD US TO CONTACT DEP. THIS WAS THE START OF THE FIFTH LEG FOR US THAT DAY. WE BOTH DIDN'T HAVE ANYTHING TO EAT SINCE STARTING THE WORK DAY. THIS COULD BE A CONTRIBUTING FACTOR SINCE OUR SCHEDULE IS NORMALLY VERY TIGHT EVEN WHEN RUNNING ON TIME. WE SHOULD HAVE VERIFIED WITH THE TWR WHEN THE CONFUSION AROSE. THE OTHER THING IS TO AVOID THE RUT OR ROUTINE THAT TRAPS YOU INTO THESE TYPE OF SITUATIONS.

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.