Two German Air Force planes intercepted and escorted a Jet Airways aircraft with more than 300 passengers and 15 crew members on board after the latter went off the radar. After a brief security scare, the flight from Mumbai to London was able to restore communication with local air traffic controllers and landed safely at Heathrow airport.

The incident, which took place on February 16, came to light after Jet Airways issued a statement on Sunday. It said that the crew of the flight had been grounded till the Directorate General of Civil Aviation investigates the episode. “Contact between Jet Airways flight 9W 118, from Mumbai to London Heathrow, of February 16, 2017, and the local ATC, was briefly lost while flying over German airspace,” read the statement.

The communication blackout reportedly happened as the pilot chose a wrong frequency to communicate, according to Aviation Herald. The incident took place when the air traffic control in Slovakia was handing over charge to Prague, reported NDTV.

A purported video of the incident is available. The video, captured by the pilot of a European airlines flight that was flying 2,000 feet above the Jet Airways flight, shows that the 9W-118 had no contact with the ATC for 15 minutes. However, the veracity of the video could not be verified.

A similar incident had taken place in 2014 when a Jet Airways aircraft was flying from London to Mumbai. Investigation had revealed that the pilot, who had removed his headphones, had forgotten to adjust the volume of the speakers, according to dna.