Narrative:

I received a 'taxi into position and hold' clearance from the tower for runway 2. While I was holding, tower cleared a military helicopter to takeoff from the north end of the runway. Immediately after that clearance was issued, tower called me, advised me that my traffic was the helicopter, to follow that traffic, and that I was cleared for takeoff. At this point, the helicopter had not yet departed. I waited for the helicopter to take the runway. He did so, lifted off, and appeared to be departing so I initiated my takeoff roll. I was flying an small aircraft so my takeoff roll was short in both time and distance. At my rotation point, it became apparent the helicopter was not departing but was continuing to hover over the north end of the runway. By the time I went through disbelief and was able to react, my aircraft was airborne. At this point, it seemed safest to continue rather than abort. I initiated a right hand turn to crosswind and departed the area. The helicopter was continually in sight. Closest horizontal approach was approximately 1200 ft with increasing vertical separation. Assessment: 1) I feel the tower should not have issued my clearance until after the helicopter was airborne and departing. 2) having observed, as PIC, many similar helicopter departures, I was predisposed to believe the helicopter was going to initiate departure immediately after liftoff as they always seem to do.

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Original NASA ASRS Text

Title: MIL HELI NON ADHERENCE TO ATC CLRNC HAD LTSS FROM SMA TKOF ON OCCUPIED RWY. PLTDEV. SYS ERROR.

Narrative: I RECEIVED A 'TAXI INTO POS AND HOLD' CLRNC FROM THE TWR FOR RWY 2. WHILE I WAS HOLDING, TWR CLRED A MIL HELI TO TKOF FROM THE N END OF THE RWY. IMMEDIATELY AFTER THAT CLRNC WAS ISSUED, TWR CALLED ME, ADVISED ME THAT MY TFC WAS THE HELI, TO FOLLOW THAT TFC, AND THAT I WAS CLRED FOR TKOF. AT THIS POINT, THE HELI HAD NOT YET DEPARTED. I WAITED FOR THE HELI TO TAKE THE RWY. HE DID SO, LIFTED OFF, AND APPEARED TO BE DEPARTING SO I INITIATED MY TKOF ROLL. I WAS FLYING AN SMA SO MY TKOF ROLL WAS SHORT IN BOTH TIME AND DISTANCE. AT MY ROTATION POINT, IT BECAME APPARENT THE HELI WAS NOT DEPARTING BUT WAS CONTINUING TO HOVER OVER THE N END OF THE RWY. BY THE TIME I WENT THROUGH DISBELIEF AND WAS ABLE TO REACT, MY ACFT WAS AIRBORNE. AT THIS POINT, IT SEEMED SAFEST TO CONTINUE RATHER THAN ABORT. I INITIATED A R HAND TURN TO XWIND AND DEPARTED THE AREA. THE HELI WAS CONTINUALLY IN SIGHT. CLOSEST HORIZ APCH WAS APPROX 1200 FT WITH INCREASING VERT SEPARATION. ASSESSMENT: 1) I FEEL THE TWR SHOULD NOT HAVE ISSUED MY CLRNC UNTIL AFTER THE HELI WAS AIRBORNE AND DEPARTING. 2) HAVING OBSERVED, AS PIC, MANY SIMILAR HELI DEPS, I WAS PREDISPOSED TO BELIEVE THE HELI WAS GOING TO INITIATE DEP IMMEDIATELY AFTER LIFTOFF AS THEY ALWAYS SEEM TO DO.

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.