This decision holds that the Court of Appeals the de novo standard of review to an order denying a nonsignatory’s motion to compel arbitration by invoking equitable estoppel. It also holds that 14 C.F.R. § 253.10 which forbids air carriers from including forum selection clauses in their contracts of carriage does not forbid an airline from relying on an arbitration clause in a third party’s (here, the agency through which the customer purchased the ticket) contract with the customer. Finally, it holds that the customer’s claim for a refund when the airline canceled the customer’s return flight was sufficiently intertwined with the customer’s contract with the ticketing agency since the airline’s contract of carriage allowed it to pay any refund to the ticketing agency, not the customer.