Widebody; Low Wing; 2 Turbojet Eng
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 7
Distraction; Situational Awareness; Workload; Communication Breakdown; Confusion
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Separated Traffic
Procedure; Human Factors
I was working Local Control-3 (LC); combined with LC-4 and LC-5.  It was late in the evening and I had just relieved another controller a few minutes earlier.  I was standing up at the time.  When I cleared Aircraft X 'RNAV TO FUTBL; RWY 27R; CLEARED FOR TAKEOFF'.  Aircraft X read back the cleared for takeoff part and then asked what I had said at the beginning.  I asked him to clarify his request and then reissued the previous instruction.  Aircraft X did not read back the 'RNAV TO FUTBL' part; but that was not abnormal for foreign carriers to omit parts of the clearance that do not require a read back.  Most of the day; the south winds were pushing aircraft within the first mile or two off the end slightly north before they established on the heading to FUTBL or SLAWW; our two RNAV fixes.  Since I was standing; I observed Aircraft X start to drift north and then lost sight of him behind the Ground Control-C (GC) ASDE-X display.  When I expected him to reappear from behind the screen he did not and then I saw on the RACD that he was significantly off course.  I issued an immediate left turn; and shouted across the tower to LC-2 that I had Aircraft X turning.  They were just starting to shout at me about Aircraft X.  Once that was settled; I issued a 230 heading Aircraft X right as DR-S called in.  I did impromptu coordination with DR-S; assuming they heard the 230 heading; and then switched Aircraft X.STOP RNAV OTG [Off The Ground]!  How many deviations do we need to have before it is determined to be an unsafe operation?  There are only a handful of ATC facilities that are easy to modify procedures; but there are millions of pilots worldwide that have to be proficient on the procedures; every time they are changed!If the above isn't possible; then anytime foreign language pilots give a controller an uneasy feeling due to the language barrier; then use headings instead of RNAV.  I should have issued the heading when Aircraft X asked me the question about what I first said in my takeoff clearance.
ATL Local Controller has a clearance problem with a foreign carrier and when the aircraft departs it drifts off the RNAV course into another Local's airspace.