Just seen on the airport website an extra flight on a Friday with Balkan holidays for next summer.
It’s not an Extra flight, but its extra capacity been added by Balkan Holidays.
As I understand that it’s just the existing summer Sunday, Balkan Holidays Air, Airbus A320's flights to Bourgas that has been re-scheduled for next summer to a Friday evening.
The service will now operate direct from and to Leeds/Bradford instead of operating outbound via Humberside, like it has done for the past couple of years.