Watch Alarm in the Clouds (1978) Official Trailer

In defiance of all the laws of physics Mr. Tau is walking on the wing of an aircraft flying close to Prague. Young Alenka is enthusiastic, but the other passengers are horrified. The security inspector Málek believes the report from the crew to be a code alerting him to a hijack, and orders an emergency landing. In the confusion at the airport the fairytale Mr. Tau disappears into one of the halls.