The pilot of a Lufthansa flight approaching Germany's busiest airport accidentally raised a national security alarm when he input the code for a hijacking.
There had been a technical problem with the communication device in the cockpit, meaning that the pilot could send but not receive messages from air traffic controllers at Frankfurt airport, a spokesman for the airline said on Monday.
To alert air traffic control to the problem, the pilot was meant to input a code, but he used the wrong one.