Narrative:

My student pilot and I were cleared (#2) into position and hold, I (we) delayed for plane in front of us starting takeoff roll. There was a lot of traffic landing and departing the runway. Sp and I believed we were given a takeoff clearance. I heard, as well as my sp, tower tell aircraft holding short of the runway, #2 position and hold. We were rolling down the runway when I had heard that, and continued taking off. Upon climb out and reaching approximately 300 ft, we were told to fly heading 040 degrees, then redirected to a heading of 030 degrees. Upon reaching heading contact ZMA. We were told to call tower when we could for a possible pilot deviation. The tower manager informed me that there was no takeoff clearance issued. I believe that the volume of traffic, along with radio congestion, may have played a role in this event. I may have been expecting the clearance, as we were taking off, one after the other. I understand in a training environment, one must maintain constant vigilance at all times when communicating with ATC. I was not vigilant enough to work with my student as a team to confirm the clearance, or lack of, in this situation.

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Original NASA ASRS Text

Title: UNCOORD UNAUTH TKOF BY A PA44 INSTRUCTOR PLT AND STUDENT AFTER HOLDING #2 IN POS ON RWY AT VRB, FL.

Narrative: MY STUDENT PLT AND I WERE CLRED (#2) INTO POS AND HOLD, I (WE) DELAYED FOR PLANE IN FRONT OF US STARTING TKOF ROLL. THERE WAS A LOT OF TFC LNDG AND DEPARTING THE RWY. SP AND I BELIEVED WE WERE GIVEN A TKOF CLRNC. I HEARD, AS WELL AS MY SP, TWR TELL ACFT HOLDING SHORT OF THE RWY, #2 POS AND HOLD. WE WERE ROLLING DOWN THE RWY WHEN I HAD HEARD THAT, AND CONTINUED TAKING OFF. UPON CLBOUT AND REACHING APPROX 300 FT, WE WERE TOLD TO FLY HEADING 040 DEGS, THEN REDIRECTED TO A HEADING OF 030 DEGS. UPON REACHING HEADING CONTACT ZMA. WE WERE TOLD TO CALL TWR WHEN WE COULD FOR A POSSIBLE PLTDEV. THE TWR MGR INFORMED ME THAT THERE WAS NO TKOF CLRNC ISSUED. I BELIEVE THAT THE VOLUME OF TFC, ALONG WITH RADIO CONGESTION, MAY HAVE PLAYED A ROLE IN THIS EVENT. I MAY HAVE BEEN EXPECTING THE CLRNC, AS WE WERE TAKING OFF, ONE AFTER THE OTHER. I UNDERSTAND IN A TRAINING ENVIRONMENT, ONE MUST MAINTAIN CONSTANT VIGILANCE AT ALL TIMES WHEN COMMUNICATING WITH ATC. I WAS NOT VIGILANT ENOUGH TO WORK WITH MY STUDENT AS A TEAM TO CONFIRM THE CLRNC, OR LACK OF, IN THIS SIT.

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.