It is interesting that they are allowed into Luton Airport - Arriva's
321 service was ejected![/i][/color]

Sadly from 23/7/16 the Metroline 714 ceased. The St Albans - Luton Airport - Luton Interchange section is covered by an hourly extension of the Metroline 84A (not Sundays). Serving all stops apparently, though I can't confirm that!