The closest airport to Sunny Beach is Burgas Airport (sometimes written Bourgas). It is just 30 km (20 miles) away from Sunny Beach. Also possible to use Varna Airport which is 100 km (60 miles) from Sunny Beach. Both Airports have almost no flights in the winter but in the summer are pretty busy. There are plenty of companies having flights to Bulgaria. I would recommend checking regularly the sites above as these are the ones we use on a regular bases, and have always been good prices.