Miami ARTCC and Havana ACC have cooperated to revise the existing routes between Florida and Cuba in an effort to improve efficiency and safety. The most significant change is the removal of the G448 airway, which until now has been the primary route between Miami ARTCC and Havana ACC. Replacing it are two RNAV airways: Y442 (southbound only) and Y183 (northbound only).
Accompanying these changes are modifications to overflight routes and existing Cuba SIDs and STARs. If you frequently fly this corridor or plan to in the future, we recommend you download and review the full presentation from Miami ARTCC (linked here) to familiarize yourself with the changes, which went into effect at 0400Z on October 12, 2017.