A class action enables a very large group of individuals (the "class"), each of whom has a similar claim against a common respondent, to pursue their claims as a single legal case.

It is useful in cases such as this where the effort and legal costs involved would be prohibitive for a single individual. Who would spend tens of thousands of pounds and a great deal of energy pursuing British Airways over lost luggage worth a few thousand pounds? A decision that British Airways have been reckless and that claims can be paid in excess of figures laid out in the Montral Convention would have to be made in the High Court - it isn't something the small claims court could decide!

Although I would appear to be virtually the only regular customer of British Airways not be in a position to benefit directly from this (they have never lost my luggage) the case seems to have a great deal of merit.