Narrative:

I contacted ground control and requested an IFR clearance to crq. The controller responded immediately with a clearance and a squawk code. I started the engine and requested a taxi clearance to runway 6. The tower responded with a taxi clearance to runway 6. The radio transmission from the tower seemed a little weak, with static. I heard no other aircraft on ground frequency. I then requested a takeoff clearance. I heard a somewhat intermittent 'nxxx cleared for takeoff.' I repeated my clearance to the controller, 'XXX cleared for departure, runway 6.' again, I heard a somewhat garbled 'XXX cleared for takeoff.' I proceeded past the hold lines, onto the runway, and aligned the plane with the centerline and advanced the throttle. As I was accelerating, I noted a small helicopter hovering in the grass (or asphalt) area between the runway and the taxiway on the south side of the airport. I continued my climb out. At about 600 ft AGL into my climb, 1/4 mi from the airport, I heard the controller transmit, 'XXX, did you just take off?' I replied 'XXX, yes (or affirmative).' the controller then transmitted, 'XXX, I did not clear you for takeoff, squawk VFR, enter right downwind for runway 6.' the controller then transmitted 'XXX, I did not clear you for takeoff, I have a helicopter on an IFR departure.' I replied, 'XXX, I requested a takeoff clearance, I thought I heard you give me one, and I repeated my clearance back to you. I thought you cleared me for takeoff.' he then transmitted, 'XXX, continue north of the field and circle, I'm working on getting you a clearance.' I circled twice at 1100 ft AGL, and the controller transmitted, 'XXX, execute a low approach, then continue as filed.' I did so, and after the low approach, continued my climb on heading and assigned altitude. Contributing factors: extremely clear WX, very little activity at the airport, radio static, and failure to clearly determine, without a doubt, my takeoff clearance. The fact that I had a squawk code prior to taxi (meaning that I would not be requesting 'ready for squawk and release.' I usually ask controllers to repeat any clearance I am at all unsure about. I also repeat every clearance, and write them down on a pad. My perception was that there was no other aircraft on the taxiway, or in any position to take off on the active runway 6, hence, any clearance for takeoff must have been directed at me. It was a little bit unusual that 2 aircraft, particularly the R22 helicopter, were departing IFR in such beautiful WX conditions. In over 2 decades of flying, this is a first. Corrective action: it would have been nice if the controller had notified me that there was helicopter activity (during my taxi). That would have been helpful information (situational awareness). I was also somewhat surprised (in hindsight) that I was able to taxi onto the runway, take off, begin a climb, and be 1/4 mi from the airport before the controller noticed the incursion. I think the controller was either working on my clearance, or distraction by the helicopter hovering in front of the tower. On a good note, I had a 6TH sense, something telling me to check the approach visually for incoming traffic before I taxied onto the runway. If there had been an aircraft on final approach, I would have seen them, and not taxied onto the runway. Because most of my flying is in southern california, I fly IFR 90% of the time, for ease of routing, and radar TA's. I will now pay particular attention to making sure I fully understand my clearance, and insist on having it repeated, if need be.

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Original NASA ASRS Text

Title: PLT OF C182 TAKES OFF FROM FUL WITHOUT CLRNC.

Narrative: I CONTACTED GND CTL AND REQUESTED AN IFR CLRNC TO CRQ. THE CTLR RESPONDED IMMEDIATELY WITH A CLRNC AND A SQUAWK CODE. I STARTED THE ENG AND REQUESTED A TAXI CLRNC TO RWY 6. THE TWR RESPONDED WITH A TAXI CLRNC TO RWY 6. THE RADIO XMISSION FROM THE TWR SEEMED A LITTLE WEAK, WITH STATIC. I HEARD NO OTHER ACFT ON GND FREQ. I THEN REQUESTED A TKOF CLRNC. I HEARD A SOMEWHAT INTERMITTENT 'NXXX CLRED FOR TKOF.' I REPEATED MY CLRNC TO THE CTLR, 'XXX CLRED FOR DEP, RWY 6.' AGAIN, I HEARD A SOMEWHAT GARBLED 'XXX CLRED FOR TKOF.' I PROCEEDED PAST THE HOLD LINES, ONTO THE RWY, AND ALIGNED THE PLANE WITH THE CTRLINE AND ADVANCED THE THROTTLE. AS I WAS ACCELERATING, I NOTED A SMALL HELI HOVERING IN THE GRASS (OR ASPHALT) AREA BTWN THE RWY AND THE TXWY ON THE S SIDE OF THE ARPT. I CONTINUED MY CLBOUT. AT ABOUT 600 FT AGL INTO MY CLB, 1/4 MI FROM THE ARPT, I HEARD THE CTLR XMIT, 'XXX, DID YOU JUST TAKE OFF?' I REPLIED 'XXX, YES (OR AFFIRMATIVE).' THE CTLR THEN XMITTED, 'XXX, I DID NOT CLR YOU FOR TKOF, SQUAWK VFR, ENTER R DOWNWIND FOR RWY 6.' THE CTLR THEN XMITTED 'XXX, I DID NOT CLR YOU FOR TKOF, I HAVE A HELI ON AN IFR DEP.' I REPLIED, 'XXX, I REQUESTED A TKOF CLRNC, I THOUGHT I HEARD YOU GIVE ME ONE, AND I REPEATED MY CLRNC BACK TO YOU. I THOUGHT YOU CLRED ME FOR TKOF.' HE THEN XMITTED, 'XXX, CONTINUE N OF THE FIELD AND CIRCLE, I'M WORKING ON GETTING YOU A CLRNC.' I CIRCLED TWICE AT 1100 FT AGL, AND THE CTLR XMITTED, 'XXX, EXECUTE A LOW APCH, THEN CONTINUE AS FILED.' I DID SO, AND AFTER THE LOW APCH, CONTINUED MY CLB ON HDG AND ASSIGNED ALT. CONTRIBUTING FACTORS: EXTREMELY CLR WX, VERY LITTLE ACTIVITY AT THE ARPT, RADIO STATIC, AND FAILURE TO CLRLY DETERMINE, WITHOUT A DOUBT, MY TKOF CLRNC. THE FACT THAT I HAD A SQUAWK CODE PRIOR TO TAXI (MEANING THAT I WOULD NOT BE REQUESTING 'READY FOR SQUAWK AND RELEASE.' I USUALLY ASK CTLRS TO REPEAT ANY CLRNC I AM AT ALL UNSURE ABOUT. I ALSO REPEAT EVERY CLRNC, AND WRITE THEM DOWN ON A PAD. MY PERCEPTION WAS THAT THERE WAS NO OTHER ACFT ON THE TXWY, OR IN ANY POS TO TAKE OFF ON THE ACTIVE RWY 6, HENCE, ANY CLRNC FOR TKOF MUST HAVE BEEN DIRECTED AT ME. IT WAS A LITTLE BIT UNUSUAL THAT 2 ACFT, PARTICULARLY THE R22 HELI, WERE DEPARTING IFR IN SUCH BEAUTIFUL WX CONDITIONS. IN OVER 2 DECADES OF FLYING, THIS IS A FIRST. CORRECTIVE ACTION: IT WOULD HAVE BEEN NICE IF THE CTLR HAD NOTIFIED ME THAT THERE WAS HELI ACTIVITY (DURING MY TAXI). THAT WOULD HAVE BEEN HELPFUL INFO (SITUATIONAL AWARENESS). I WAS ALSO SOMEWHAT SURPRISED (IN HINDSIGHT) THAT I WAS ABLE TO TAXI ONTO THE RWY, TAKE OFF, BEGIN A CLB, AND BE 1/4 MI FROM THE ARPT BEFORE THE CTLR NOTICED THE INCURSION. I THINK THE CTLR WAS EITHER WORKING ON MY CLRNC, OR DISTR BY THE HELI HOVERING IN FRONT OF THE TWR. ON A GOOD NOTE, I HAD A 6TH SENSE, SOMETHING TELLING ME TO CHK THE APCH VISUALLY FOR INCOMING TFC BEFORE I TAXIED ONTO THE RWY. IF THERE HAD BEEN AN ACFT ON FINAL APCH, I WOULD HAVE SEEN THEM, AND NOT TAXIED ONTO THE RWY. BECAUSE MOST OF MY FLYING IS IN SOUTHERN CALIFORNIA, I FLY IFR 90% OF THE TIME, FOR EASE OF ROUTING, AND RADAR TA'S. I WILL NOW PAY PARTICULAR ATTN TO MAKING SURE I FULLY UNDERSTAND MY CLRNC, AND INSIST ON HAVING IT REPEATED, IF NEED BE.

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.