A PART 91 GA PLT ERRS IN HIS ASSUMPTIONS REGARDING THE VECTOR GIVEN BY DEP CTLR AND GETS INTO PROX OF MOUNTAINOUS TERRAIN ON THE NOTWN1 DEP FROM VGT; NV.

Narrative

I HAD FILED AND RECEIVED AN INST CLRNC FROM THE NORTH LAS VEGAS ARPT WHICH INCLUDED THE NORTH TOWN 1 DEP. THE TWR OPERATOR HAD CLRED A NAVION TO TAKE OFF IN FRONT OF ME AND WHEN HE CLRED ME TO TAKE OFF FROM RWY 30L; HE INSTRUCTED ME TO KEEP THE NAVION TO MY L. THE NORTH TOWN 1 DEP REQUIRES AN AIRPLANE TO INITIALLY STEER 250 DEGS. WHEN I DEPARTED THE RWY; I COULD NOT LOCATE THE NAVION TO MAINTAIN VISUAL SEPARATION AND HAD NOT STARTED MY TURN TO 250 DEGS. THE TWR CTLR INSTRUCTED ME TO CONTACT THE APCH CTLR. WHEN I CHKED IN WITH THE APCH CTLR; HE TOLD ME TO FLY HEADING 250 DEGS. BECAUSE HE HAD GIVEN ME A HEADING TO FLY; I THOUGHT THAT HE WAS THEN GOING TO GIVE ME RADAR VECTORS INSTEAD OF ME CONTINUING WITH THE SID. I WAS IN VMC AND GETTING CLOSER TO THE RISING TERRAIN WHEN THE CTLR CALLED ME TO MAINTAIN VISUAL SEPARATION FROM THE TERRAIN AND TURN TO THE N FROM 250 DEGS. HE THEN GAVE ME A TELEPHONE NUMBER TO CALL WHEN I GOT TO MY DEST. I CONTINUED MY FLT AND LANDED IN ARIZONA AND CALLED THE TELEPHONE NUMBER. THE PROB WAS CAUSED BY ME THINKING THAT HE WAS GOING TO GIVE ME RADAR VECTORS WHEN HE GAVE ME A HEADING TO FLY ALTHOUGH HE DIDN'T STATE THAT HE WOULD PROVIDE RADAR VECTORS. I WAS FULLY PREPARED TO FLY THE SID PRIOR TO HIS STATEMENT TO 'FLY HEADING 250 DEGS;' ALTHOUGH THE TWR CTLR CAUSED A PROB BY REQUIRING ME TO 'KEEP THE NAVION TO MY L AFTER DEP' AND THEREFORE KEEP MY VISION OUTSIDE THE COCKPIT WHEN I WOULD NORMALLY BE BUSY FLYING THE INST PROC DURING TKOF ACTIVITY. I HAD THE NAVION IN SIGHT AT THE START OF MY TKOF ROLL; BUT AFTER CHKING MY INSTS AND AIRSPD INDICATOR FOR PROPER ACTIVITY; WHEN I LOOKED BACK UP I COULDN'T VISUALLY LOCATE THE NAVION. I WAS AFRAID TO TURN TO 250 DEGS BEFORE LOCATING THE POS OF THE NAVION. THIS PROB COULD BE PREVENTED BY THE TWR OPERATOR WAITING A LITTLE LONGER TO CLR AN INST DEP UNTIL THE VFR TFC IS CLR OF THE IFR RTE. THE SECOND FACTOR WILL BE THAT I MISUNDERSTOOD THE INSTRUCTIONS OF THE DEP CTLR WHEN HE SAID TO 'TURN TO 250 DEGS.' I WILL CERTAINLY BE QUICKER TO QUERY A CTLR IF I'M UNSURE OF CLRNCS IN THE FUTURE.