Narrative:

After being cleared to cross fathr at FL240 and while passing through FL310 we were informed to expedite our descent through FL270 by miami center. When passing through FL300 we were abruptly told to level off. We noticed another aircraft on the TCAS coming directly at us from the south. We also noticed that the altitude difference between us was steadily decreasing from 1;400 ft on down. When we got a TCAS RA and the order to climb the first officer (flying at the time) executed the avoidance procedure. Considering the fact that I observed a 200 foot difference between us and the intruding aircraft as its symbol passed through our aircraft symbol I believe that had the first officer not executed the RA procedure in the appropriately and timely manner in which he did we would have very likely been involved in a catastrophic mid-air collision. After being unable to get into fll due to severe thunderstorm activity we diverted to mia. While on the ground there I called the ATC supervisor and was told that an international airlines jet which caused the problem was not following the ATC instructions given to avoid us and was deviating for weather. Our weather radar indicated that there was nothing in the area that necessitated a deviation.

Google
 

Original NASA ASRS Text

Title: Air Carrier inbound to FLL experienced a TCAS RA; ATC reported the other aircraft involved failed to follow ATC instructions.

Narrative: After being cleared to cross FATHR at FL240 and while passing through FL310 we were informed to expedite our descent through FL270 by Miami Center. When passing through FL300 we were abruptly told to level off. We noticed another aircraft on the TCAS coming directly at us from the south. We also noticed that the altitude difference between us was steadily decreasing from 1;400 FT on down. When we got a TCAS RA and the order to climb the First Officer (flying at the time) executed the avoidance procedure. Considering the fact that I observed a 200 foot difference between us and the intruding aircraft as its symbol passed through our aircraft symbol I believe that had the First Officer not executed the RA procedure in the appropriately and timely manner in which he did we would have very likely been involved in a catastrophic mid-air collision. After being unable to get into FLL due to severe thunderstorm activity we diverted to MIA. While on the ground there I called the ATC Supervisor and was told that an international airlines jet which caused the problem was NOT following the ATC instructions given to avoid us and was deviating for weather. Our weather radar indicated that there was nothing in the area that necessitated a deviation.

Data retrieved from NASA's ASRS site as of July 2013 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.