Narrative:

We were informed that we were 15 mi southeast of course at the above mentioned area by havana center. This occurred because if you look at the commercial chart (la(hil)3), the radial out of cozumel VOR is 048 degrees, then after nukan intersection, there is what appears to be an azimuth change to 051 degrees. This azimuth change caused our being the alleged 15 mi southeast off course. Also, a contributing factors was the great thunderstorm activity in the area of occurrence. The 051 degree azimuth track was keeping us away from a cell, whereas the 048 degree track would have put us in the cell. But ultimately, the 051 degree depiction just after nukan intersection was the chief cause of this deviation. We certainly would have requested a deviation right of course to avoid the cell activity. (Also, 15 mi seems to be more than what we were off course in reality.) we then were told of the problem, we were able to correct left because the cell was now behind us. We apologized and went to the 048 degree radial. By this time, key west VOR was starting to be usable and was used to verify what was on course.

Google
 

Original NASA ASRS Text

Title: MLG ACFT ON OCEANIC AIRWAY DEVIATED FOR WX, BUT RPTR CAPT AND FO FAULT THE AIRWAY NAV CHART. CTLR INTERVENED TELLING THEM THEY WERE 15 MI OFF COURSE AND THEY CORRECTED BACK.

Narrative: WE WERE INFORMED THAT WE WERE 15 MI SE OF COURSE AT THE ABOVE MENTIONED AREA BY HAVANA CTR. THIS OCCURRED BECAUSE IF YOU LOOK AT THE COMMERCIAL CHART (LA(HIL)3), THE RADIAL OUT OF COZUMEL VOR IS 048 DEGS, THEN AFTER NUKAN INTXN, THERE IS WHAT APPEARS TO BE AN AZIMUTH CHANGE TO 051 DEGS. THIS AZIMUTH CHANGE CAUSED OUR BEING THE ALLEGED 15 MI SE OFF COURSE. ALSO, A CONTRIBUTING FACTORS WAS THE GREAT TSTM ACTIVITY IN THE AREA OF OCCURRENCE. THE 051 DEG AZIMUTH TRACK WAS KEEPING US AWAY FROM A CELL, WHEREAS THE 048 DEG TRACK WOULD HAVE PUT US IN THE CELL. BUT ULTIMATELY, THE 051 DEG DEPICTION JUST AFTER NUKAN INTXN WAS THE CHIEF CAUSE OF THIS DEV. WE CERTAINLY WOULD HAVE REQUESTED A DEV R OF COURSE TO AVOID THE CELL ACTIVITY. (ALSO, 15 MI SEEMS TO BE MORE THAN WHAT WE WERE OFF COURSE IN REALITY.) WE THEN WERE TOLD OF THE PROB, WE WERE ABLE TO CORRECT L BECAUSE THE CELL WAS NOW BEHIND US. WE APOLOGIZED AND WENT TO THE 048 DEG RADIAL. BY THIS TIME, KEY WEST VOR WAS STARTING TO BE USABLE AND WAS USED TO VERIFY WHAT WAS ON COURSE.

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.