airliner are not only refused for being unsafe, but also for (for instance) not paying airport and ATC bills.

This probably also happened to Cameroon Airlines as they where banned for: “Non payment of Carriers Liability Act fines“. In the meantime they may have paid off their debts thus regaining permission to fly to the UK.

With Enimex it says that their permit has been restored april 30th ’03.

Same goes with RAF Avia, there it says their permit was returned July 26th ’03. They had been banned for not having a proper lease deal for the aircraft. By now they probably amended the deal and/or changed planes.

Star Air still seems to be banned.