Narrative:

Departure clearance was jom departure A590...flight plan route. Cleared to FL250 initially to expect FL370. Runway in use was runway 24. Cleared into position and told to be ready for an immediate takeoff at XA52 local. Shortly after, cleared for an immediate takeoff. Passing 500 ft MSL tower made a transmission that was garbled. PNF asked tower to repeat last transmission. Tower responded with 'contact departure control on 121.1.' PF continued departure SID which required 180 degree left turn. PNF contacted departure control with passing altitude and turning left to 060 degrees. Departure asked to confirm turning left. PNF answered in the affirmative to which departure inquired if tower had given us runway heading. PNF answered negative to which departure asked if we were sure. PNF responded he was quite certain tower never assigned us runway heading. We continued the departure SID and were cleared direct jom shortly after. We never idented any conflict either visually or on TCASII. This appears to be a case of miscom. Tower could have given us runway heading on his first transmission after takeoff but we never heard it because of a garbled radio. Tower's second transmission was a frequency change only. Contributing factor here is that a departure frequency was not assigned on ground nor is the frequency printed on the -9 page or SID pages. This omission, which is standard procedure, just adds to communication difficulties which are already challenging with poor quality of radios and language restraints.

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Original NASA ASRS Text

Title: ACR IN FOREIGN OP FLIES SID WHEN TWR EXPECTS STRAIGHT OUT DEP.

Narrative: DEP CLRNC WAS JOM DEP A590...FLT PLAN RTE. CLRED TO FL250 INITIALLY TO EXPECT FL370. RWY IN USE WAS RWY 24. CLRED INTO POS AND TOLD TO BE READY FOR AN IMMEDIATE TKOF AT XA52 LCL. SHORTLY AFTER, CLRED FOR AN IMMEDIATE TKOF. PASSING 500 FT MSL TWR MADE A XMISSION THAT WAS GARBLED. PNF ASKED TWR TO REPEAT LAST XMISSION. TWR RESPONDED WITH 'CONTACT DEP CTL ON 121.1.' PF CONTINUED DEP SID WHICH REQUIRED 180 DEG L TURN. PNF CONTACTED DEP CTL WITH PASSING ALT AND TURNING L TO 060 DEGS. DEP ASKED TO CONFIRM TURNING L. PNF ANSWERED IN THE AFFIRMATIVE TO WHICH DEP INQUIRED IF TWR HAD GIVEN US RWY HEADING. PNF ANSWERED NEGATIVE TO WHICH DEP ASKED IF WE WERE SURE. PNF RESPONDED HE WAS QUITE CERTAIN TWR NEVER ASSIGNED US RWY HEADING. WE CONTINUED THE DEP SID AND WERE CLRED DIRECT JOM SHORTLY AFTER. WE NEVER IDENTED ANY CONFLICT EITHER VISUALLY OR ON TCASII. THIS APPEARS TO BE A CASE OF MISCOM. TWR COULD HAVE GIVEN US RWY HEADING ON HIS FIRST XMISSION AFTER TKOF BUT WE NEVER HEARD IT BECAUSE OF A GARBLED RADIO. TWR'S SECOND XMISSION WAS A FREQ CHANGE ONLY. CONTRIBUTING FACTOR HERE IS THAT A DEP FREQ WAS NOT ASSIGNED ON GND NOR IS THE FREQ PRINTED ON THE -9 PAGE OR SID PAGES. THIS OMISSION, WHICH IS STANDARD PROC, JUST ADDS TO COM DIFFICULTIES WHICH ARE ALREADY CHALLENGING WITH POOR QUALITY OF RADIOS AND LANGUAGE RESTRAINTS.

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.