The law allows a company to 'lock-out' an employee for the duration of the industrial action. In this case, as more strikes have been called, this would be until there is no further threat of industrial action. Any days that the crew are suspended do not count towards the twelve weeks during which dismissal would be deemed to be unfair.
There is nothing in UK law to prevent BA removing staff travel, so long as all strikers are treated equally.
Taking part in industrial action : Directgov - Employment
Dave