Key pointsAviation unions threaten to stop operations of airlines accused of failing to remit Ticket Sales Charges (TSC). The unions say the unpaid statutory charges are affecting the operations of key aviation agencies. Main storyAviation unions have threatened to halt the operations of some airlines after the expiration of a seven-day ultimatum over the alleged non-remittance of Ticket Sales Charges (TSC) collected on behalf of aviation agencies. The issuesTicket Sales Charges are statutory fees collected by airlines from passengers on behalf of aviation agencies. Bottom lineA standoff over Ticket Sales Charges has escalated into a potential industry shutdown, with aviation unions threatening action while airline operators deny any wrongdoing, raising the prospect of disruption for airlines and passengers if the dispute is not quickly resolved.