When the Jet aircraft was at about 37km north of Cologne, it was intercepted by a German fighter to its left, only to be joined minutes later by a second jet. The Jet pilots later used the emergency frequency to establish contact with the air traffic control.A Jet Airways spokesperson confirmed the incident. "Contact between Jet Airways flight 9W 118... and the local ATC, was briefly lost while flying over German airspace. As a precaution, the German Air Force deployed its aircraft to ensure the safety of the flight and its guests.'' In this case, the Jet pilots re-established communication with the air traffic controller even before the interception exercise began.

Source: Times of India February 19, 2017 20:07 UTC