A DEP ACR COMPLAINS ABOUT A ROTARY WING ACFT OPERATING OFF THE END OF RWY.

Narrative

DURING A NIGHT OP; THE TWR CLRED US FOR TKOF ON 26R. WHILE TAXIING ONTO THE RWY; WE OBSERVED AN ACFT XING THE DEP END OF OUR RWY AT APPROX 500 FT AGL. PRIOR TO OUR SETTING TKOF THRUST; THE ACFT TURNED L AND APPEARED TO BE DEPARTING THE AREA TO THE S. AFTER REACHING VR; THE ACFT REAPPEARED SLIGHTLY TO THE L OF OUR CENTERLINE; NEAR THE DEP END AT 400-500 FT AGL. UP TO THIS TIME; ATC HAD NOT ADVISED US OF ANY TFC. DURING INITIAL CLB OUT WE PASSED WITHIN 300 FT AGL. THE SID PROC CALLS FOR A L TURN; SBOUND AFTER DEP. HAD WE NOT SEEN THE HELI AND ENGAGED LNAV TO BEGIN OUR TURN AS PUBLISHED; A MID-AIR COULD HAVE OCCURRED. UPON QUESTIONING THE TWR ABOUT THE PROX OF THE TFC; THE TWR STATED THAT THE HELI HAD US IN SIGHT. AGAIN; HOWEVER; WE WERE NOT ADVISED OF THIS TFC. I CONTACTED THE TWR SUPVR AFTER REACHING OUR DEST. THE SUPVR STATED HE HAD RECEIVED A MESSAGE FROM THE ON-DUTY CTLR IN REF TO THE OCCURRENCE. THE SUPVR INFORMED US HE WOULD DISCUSS THE ISSUE WITH THE CTLR TO ENSURE A SAFER OP BY ISSUING TAS TO BOTH ACFT WHEN IN CLOSE PROX.