Complex sentence: Airlines added new frequencies to the current routes and started many new destinations, such as JetBlue, which started three weekly flights to Boston, Aerolineas MAS, adding domestics flights to Punta Cana three times per week.
Split into simpler sentences: Airlines added new frequencies to the current routes and started many new destinations. Such airlines are JetBlue, which started three weekly flights to Boston, Aerolineas MAS, adding domestics flights to Punta Cana three times per week.