AAE and XLA are merging. TCD was bought by the Avion Group last year and the flights have been operated by AAI and AAE crews for some time now anyhow and never operated on their own callsign. Since November last year the crews became solely AAE. With the merger AAE will cease to exist and so will the 5A/EUK/Snowbird identifiers hence the change from 5A to XL.