ALTDEV ALT OVERSHOT. WRONG ALTIMETER SETTING PROC USED.

Narrative

AS OUR FLT WAS ARRIVING INTO THE TERMINAL AREA OF SVO FROM THE SW; WE WERE GIVEN WHAT WOULD BE CONSIDERED NORMAL NAV AND ALT CLRNCS. THEN THE CLRNC WAS 'PROCEED DIRECT TO UM BEACON.' THE ALTS WERE GIVEN IN 'LEVELS' AND THEN IN 'METERS' WITH AN UPDATE OF THE ALTIMETER SETTING. WE ACCIDENTALLY MISINTERPRETED THE ALTIMETER SETTING AS INCHES OF MERCURY INSTEAD OF HECTOPASCALS. THE CONFUSION STARTED NOT OVER ALT; BUT LATERAL FLT PATH BECAUSE ATIS INFO HAD JUST GIVEN RWY 7R AS THE ACTIVE; AND AS WE APCHED UM WE WERE EXPECTING AN APCH CLRNC AND NONE CAME OVER. I ASKED IF WE WERE CLRED FOR THE APCH TO RWY 7; AND THE CTLR SAID NO; GO DIRECT TO BW. WE LOOKED ALL OVER OUR APCH PLATES (RWY 7R) AND WERE CONFUSED OVER THE USE OF THIS NAVAID. THEN WE GOT AN ASSIGNED HDG OF ABOUT 050 DEGS; AN ALT CHANGE; AND WERE INFORMED THAT THE ACTIVE RWY WAS RWY 25L. (BW IS THE PRIMARY APCH AID FOR RWY 25L.) BY NOW WE WERE SCRAMBLING FOR ANOTHER APCH PLATE; LOCATED BW; AND STARTED TO GET ORIENTED FOR RWY 25L FOLLOWING THE CTLR'S RADAR VECTOR AND ALT ASSIGNMENTS. ON THE WAY DOWN WHEN ATC CHANGED THE ALT FROM 'LEVELS' TO 'METERS' HE GAVE AN ALTIMETER SETTING OF '999.' THAT OF COURSE WAS IN HECTOPASCALS BUT WE INTERPRETED IT TO BE 29.99 INCHES OF MERCURY. THEN WHEN VECTORED ONTO BASE LEG THE CTLR ASKED OUR ALT. I RPTED 600 METERS (AS WAS ASSIGNED) AND CHKED MY RADIO ALTIMETER WHICH INDICATED ABOUT 1400 FT ABOVE THE GND. THEN ON FINAL APCH INTERCEPT HDG HE INQUIRED AGAIN AND SAID WE WERE TOO LOW. THE CORRECT ALT WAS IN FACT 600 METERS (ABOUT 2000 FT); BUT THAT IS ABOVE THE GND; NOT MSL. WE HAD THE CORRECT FT-TO- METER CALCULATION; BUT THE WRONG ALTIMETER SETTING RESULTING IN AN ERROR OF ABOUT 600 FT. BY THEN WE WERE GETTING NEAR THE ARPT ABOUT TO TIE ONTO THE LOC AND GS WITH THE RADIO ALTIMETER STILL SHOWING 1400 FT. WE WERE CLRED FOR THE APCH AND MADE AN UNEVENTFUL LNDG. ALL 3 OF US WERE ACTIVELY INVOLVED IN THE CLRNCS; AND NEITHER OF US CAUGHT THE MISTAKE EVEN THOUGH IT HAD BEEN EMPHASIZED TO US IN TRAINING. IN THAT I WAS PIC OF THE ACFT I MUST ASSUME FULL RESPONSIBILITY FOR THIS ERROR. FORTUNATELY IT WAS DAY VFR IN VERY CLR WX; AND EXCEPT FOR NOISE ABATEMENT; WE DID NOT EXPOSE OURSELVES TO ANY REAL TROUBLE. A FEW OTHER FACTORS MIGHT BE CONSIDERED AS CONTRIBUTING TO THIS INCIDENT: THE LANGUAGE BARRIER MAKES IT DIFFICULT TO UNDERSTAND THE CLRNCS; AND OFTEN WE HAD TO ASK FOR REPEATS. THIS IS OF COURSE OUR PROB AS WELL AS THEIRS AND REQUIRES EXTRA VIGILANCE. HAD THE CTLR SAID; '999 HECTOPASCALS' IT WOULD HAVE HELPED. THE ATIS INDICATED RWY 7R AND THE ACTIVE RWY WAS 25L. WE WERE VERY DISTRACTED IN OBTAINING AND SETTING CORRECT ALTIMETER SETTING WITH ALL OF THE CONFUSION AND MISALIGNMENT OF WHAT WE THOUGHT WAS THE ACTIVE RWY. ALL 3 PLTS WERE FAIRLY NEW TO TRANSOCEANIC INTL OPS. IT WAS MY FIRST TRIP TO RUSSIA; AND ONLY THE SECOND FOR BOTH OF THE COPLTS.