Hi
Looking at the Jet2 scheduled for next summer at LBA, The Base only needs 10 aircraft which will be 3 X 757-200's & 7 X 737-300's due to cut backs on some of the services plus the evening Belfast Int'l service will be operated by a Irish based aircarft as well instead.
So that releases the missing 1 x Boeing 737-300 thats required for the EDI..