Narrative:

We had just slowed from (an approved) high speed descent and were under radar vectors from the final controller at incheon international, korea (rksi). There was preceding traffic, and radio communication was heavy. The controller was difficult to understand due to his considerable accent. Additionally, there was radio traffic on guard (121.5), adding to the cacophony. We had been assigned a heading of 270 degrees, and at about 15 mi, all 3 of us thought we heard 'maintain 300 degrees, intercept the localizer.' the captain read back these instructions, and about 10 seconds later, we began rolling out on the localizer to runway 33R. The captain then radioed 'intercepting localizer' at which point an evidently alarmed controller replied that we were to 'maintain 300 degrees and fly through the localizer.' we immediately turned back to 300 degree heading. After some more heavy radio chatter to other aircraft, the controller inquired as to why we intercepted the localizer. We replied that this was what we understood his instructions to be, and that his communications were difficult to understand. We further thought, although we did not communicate this, that this inquiry in the middle of our approach was highly inappropriate. At no time did we get near other traffic -- our closest traffic being the preceding flight at 4 mi. After a few more ATC directed s-turns, we captured the ILS and flew an uneventful approach to runway 33R. We heard no further inquiries on the ground.

Related reports:

Google
 

Original NASA ASRS Text

Title: A CARGO TRIJET CAPT RPTED THAT THE RKSI TRACON CTLR WAS HARD TO UNDERSTAND WHICH CAUSED THE CREW TO MISUNDERSTAND THEIR CLRNC.

Narrative: WE HAD JUST SLOWED FROM (AN APPROVED) HIGH SPD DSCNT AND WERE UNDER RADAR VECTORS FROM THE FINAL CTLR AT INCHEON INTL, KOREA (RKSI). THERE WAS PRECEDING TFC, AND RADIO COM WAS HVY. THE CTLR WAS DIFFICULT TO UNDERSTAND DUE TO HIS CONSIDERABLE ACCENT. ADDITIONALLY, THERE WAS RADIO TFC ON GUARD (121.5), ADDING TO THE CACOPHONY. WE HAD BEEN ASSIGNED A HDG OF 270 DEGS, AND AT ABOUT 15 MI, ALL 3 OF US THOUGHT WE HEARD 'MAINTAIN 300 DEGS, INTERCEPT THE LOC.' THE CAPT READ BACK THESE INSTRUCTIONS, AND ABOUT 10 SECONDS LATER, WE BEGAN ROLLING OUT ON THE LOC TO RWY 33R. THE CAPT THEN RADIOED 'INTERCEPTING LOC' AT WHICH POINT AN EVIDENTLY ALARMED CTLR REPLIED THAT WE WERE TO 'MAINTAIN 300 DEGS AND FLY THROUGH THE LOC.' WE IMMEDIATELY TURNED BACK TO 300 DEG HDG. AFTER SOME MORE HVY RADIO CHATTER TO OTHER ACFT, THE CTLR INQUIRED AS TO WHY WE INTERCEPTED THE LOC. WE REPLIED THAT THIS WAS WHAT WE UNDERSTOOD HIS INSTRUCTIONS TO BE, AND THAT HIS COMS WERE DIFFICULT TO UNDERSTAND. WE FURTHER THOUGHT, ALTHOUGH WE DID NOT COMMUNICATE THIS, THAT THIS INQUIRY IN THE MIDDLE OF OUR APCH WAS HIGHLY INAPPROPRIATE. AT NO TIME DID WE GET NEAR OTHER TFC -- OUR CLOSEST TFC BEING THE PRECEDING FLT AT 4 MI. AFTER A FEW MORE ATC DIRECTED S-TURNS, WE CAPTURED THE ILS AND FLEW AN UNEVENTFUL APCH TO RWY 33R. WE HEARD NO FURTHER INQUIRIES ON THE GND.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.