CB AN ACR FREIGHTER DRIFTS SLIGHTLY OFF COURSE ON THE CHOSHI 8 SID DEP PROC WHEN THE CAPT DOES NOT FLY A TRACK BUT A HDG AFTER TKOF FROM NRT; FO.

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THE CHOSHI 8 DEP; RWY 16; HAS HAD ITS PROBS BECAUSE IT IS A DEP THAT USES ADF'S. WE HAD 27 KTS OF XWIND AFTER LIFTOFF; MODERATE TURB; AND RAIN ON THIS DEP. THE SID DOES NOT SPECIFY 'TRACK' 156 DEGS BUT INSTEAD SAYS CLB ON 156 DEGS; WHICH CAUSES CONFUSION. WE MAY HAVE DRIFTED R OF COURSE DUE TO THE STRONG XWIND BUT WERE NEVER TOLD THAT WE HAD VIOLATED THE CORRIDOR. CONSEQUENTLY THIS NASA RPT IS BEING SUBMITTED AS A PRECAUTION. THE SIDS OUT OF NEW TOKYO (RJAA) ARPT NEED TO BE REVISED TO USE MODERN NAVAIDS THAT ARE CURRENTLY ON THE FIELD. USING ADF'S FOR DEP SIDS WILL CONTINUE TO CAUSE PROBS; ESPECIALLY WHEN STRONG XWINDS EXIST. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE CREW FLYING A DC10 FREIGHTER. THERE IS A 4 DEG TOLERANCE ALLOWED ON THEIR COMPASSES FOR TKOF WHICH WOULD CREATE A PROB OF ACCURACY IN THEIR TRACKING TECHNIQUE USING THE RMI FOR BEARING INFO. THEIR RMI IS VERY SMALL AND HARD TO READ; PARTICULARLY DURING A RAINY; WIND SWEPT DAY WITH TURB AND XWINDS. IT'S 'A LOT OF WORK.' THE CAPT IS USED TO THESE TYPE NAV PROCS BUT THIS ONE IS 'TOO MUCH.' THE CORRIDOR THEY MUST ADHERE TO IS ONLY 1.5 MI WIDE; PRESUMABLY FOR NOISE ABATEMENT PROCS FROM RWY 34 AND RWY 16. THE AMOUNT OF DRIFT VARIES DUE TO THE TREE LINE W OF THE RWYS. THIS ARPT EXPERIENCES STRONG XWINDS. ONCE AIRBORNE; THE WINDSHEAR EFFECT IS PRONOUNCED; WITH A QUICK DRIFT BEING EXPERIENCED. THE RPTR STATED THAT THERE WERE 21 FLTS THAT WERE OFF COURSE THIS DAY; THE DEP CTLR WAS 'OVERWHELMED' WITH THE LOAD AND DID NOT TRY TO CORRECT THE SIT; COULD NOT. THE FMS EQUIPPED ACFT WERE AMONG THOSE EXPERIENCING OFF COURSE TRACKS. THE CAPT EXPLAINED THAT 10 YRS AGO THE PROC WAS TO FLY THE VOR 157 DEG OR THE 337 DEG RADIAL AND THAT APPEARED TO WORK. THE CORRIDOR WAS REALIGNED; USING THE BEACONS 'KF' AND 'YQ' WHICH DOES NOT WORK. ATTEMPTING TO USE THE NRE VOR 336 DEG AND 156 DEG RADIALS DOESN'T WORK EITHER SINCE THE VOR IS OFF CTR FROM THE RWYS. THE CAPT HAS TRIED USING THE INS TO FLY THE TRACK; USING THE COORDINATES OF THE BEACON AS WAYPOINT #1; USING THE COURSE DISPLACEMENT INDICATOR AS A GUIDE TO STAY IN THE CORRIDOR. HIS COMPANY HAS TRIED THIS OUT IN THE SIMULATOR. THE COMPANY HAS SENT A LETTER TO ATC IN THE REGION REGARDING THIS PROB BUT THE CAPT WOULD APPRECIATE ANY ADDITIONAL EFFORTS MADE BY ANY OTHER AGENCIES.