Thanks for the comments. I have wondered why they acquired G-SAYE in the first place as it is a lower spec a/c than G-LGIS (it has a lower MTOW, hence reduced capacity). It seems to me as well that if they need 2 a/c operational every day to offer the ACI service, then relying on a 31 year old a/c as part of a fleet of 3 is perhaps being a little optimistic. I guess that they should have bought 3 new a/c once they had decided on the move to Dorniers, but perhaps they weren't allowed to do so.