Commuter takeoff without clearance.

Attributes
ACN	80861
Time
Date	198801
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : mdt
State Reference	PA
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
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 : atp
Experience	flight time last 90 days : 215 flight time total : 3600 flight time type : 2300
ASRS Report	80861
Person 2
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	incursion : runway non adherence : clearance
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

It was the last leg of the day from mdt to hgr. As we taxi out to the run up block we pulled behind another commuter and called ready in sequence. Then we were clrd into position and hold. As we pulled onto the runway my first officer brought the speeders up and the lights on and told me we were clrd to go. I then advanced power and took off. Mdt tower advised me I was not clrd to go, and to contact departure. No evasive action was needed. I believe the reason I did not hear the call clearly was because of the taxi around the commuter in front of me was somewhat tight. And, my mistake was not to confirm the clearance. After talking to my first officer, he believed he heard clrd to go. Occasionally, controllers use the phrase 'clrd to go,' not putting any blame on them. I see the importance of using correct phrases all the time between controllers and pilots.

Original NASA ASRS Text

Title: COMMUTER TKOF WITHOUT CLRNC.

Narrative: IT WAS THE LAST LEG OF THE DAY FROM MDT TO HGR. AS WE TAXI OUT TO THE RUN UP BLOCK WE PULLED BEHIND ANOTHER COMMUTER AND CALLED READY IN SEQUENCE. THEN WE WERE CLRD INTO POS AND HOLD. AS WE PULLED ONTO THE RWY MY F/O BROUGHT THE SPEEDERS UP AND THE LIGHTS ON AND TOLD ME WE WERE CLRD TO GO. I THEN ADVANCED PWR AND TOOK OFF. MDT TWR ADVISED ME I WAS NOT CLRD TO GO, AND TO CONTACT DEP. NO EVASIVE ACTION WAS NEEDED. I BELIEVE THE REASON I DID NOT HEAR THE CALL CLEARLY WAS BECAUSE OF THE TAXI AROUND THE COMMUTER IN FRONT OF ME WAS SOMEWHAT TIGHT. AND, MY MISTAKE WAS NOT TO CONFIRM THE CLRNC. AFTER TALKING TO MY F/O, HE BELIEVED HE HEARD CLRD TO GO. OCCASIONALLY, CTLRS USE THE PHRASE 'CLRD TO GO,' NOT PUTTING ANY BLAME ON THEM. I SEE THE IMPORTANCE OF USING CORRECT PHRASES ALL THE TIME BTWN CTLRS AND PLTS.

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.