AN AIRBUS A310 IS PERCEIVED TO HAVE MADE AN EARLY TURN AT IDALE WHEN FLYING THE WYLDD RNAV 2 DEP FROM LAS; NV.

Narrative

CLRED WYLDD 2 (RNAV) DEP. LAS TWR CLRED US (ACR X) FOR TKOF RWY 25L AND TO RPT THE ACR Y FLT I SIGHT (HE HAD JUST LIFTED OFF). ON CLBOUT (CLRED TO FL290) AFTER PASSING THE EYNE FIX ENRTE TO IDALE; WITH A PROGRAMMED TURN TO HITME FIX; THE FMS CALCULATED A TURN (APPROX 100 DEGS) WITH A LEAD POINT SO AS NOT TO OVERFLY IDALE. IDALE IS NOT A MANDATORY FLYOVER POINT AS DEPICTED; SO THE FMS MADE ITS CALCULATIONS ACCORDINGLY. ACR Y WAS ON THE SAME DEP AS US; BUT WAS CLOSER TO IDALE BEFORE STARTING HIS TURN. SINCE OUR TURN RADIUS WAS INSIDE HIS; AND WE WERE OUTCLBING HIM; WE WERE CONCERNED ABOUT OUR SEPARATION AND QUERIED THE CTLR WHILE LEVELING OFF AT 10000 FT MSL. HIS REPLY WAS OUR INQUIRY WAS 'WHY DID WE TURN EARLY?' THERE WAS NO LOSS OF SEPARATION AND WE HAD THE ACR Y FLT IN SIGHT AT ALL TIMES. A DIFFERENT CTLR CAME ON AND WE CONTINUED OUR CLB. THE FLT CONTINUED AND NO MORE WAS SAID BY THE CTLRS. I BELIEVE THAT A CLARIFICATION SHOULD BE MADE WHETHER OR NOT THE CTLRS EXPECT ACFT TO FLY OVER IDALE OR USE APPROPRIATE LEAD POINTS. THERE WAS NOTHING IN THE NOTAMS OR ON THE CURRENT ATIS. ALSO; NO SPD RESTR IS DEPICTED; SO WHEN PASSING 10000 FT; THE FMS CALCULATES A TURN USING A FASTER SPD; THUS REQUIRING A LONGER LEAD POINT. SINCE WE WERE CLBING FASTER THAN ACR Y; THIS MAY HAVE BEEN A FACTOR.