Germany’s Verdi trade union has called on security personnel at Frankfurt and Hamburg airports to join a strike by Lufthansa ground staff later this week. This means that passengers will probably not be able to enter these two airports. The workers are employed by private companies that check passengers, staff and luggage at the entrances to the security area on behalf of the Federal Police. The strike by Lufthansa ground staff begins on Wednesday evening and is scheduled to continue until Saturday morning at 7:10 am (0610 GMT). Lufthansa passenger flights are expected to face major disruption…