Frankfurt Airport's new Sky Line train (Line 2) is out of service for technical inspections, forcing passengers to use shuttle buses between terminals. The train, which opened a month ago, was designed to transport up to 4,000 passengers per hour efficiently. The reopening timeline is uncertain, but Fraport is working to restore service. The new Terminal 3 is set to open on June 9, aiming to accommodate 19 million passengers annually, despite delays caused by the train's shutdown.