The crew of the flight from Delhi contacted Jet Airways' flight operations in India which then used the aircraft communication and addressing system (ACARS) or a satellite phone to contact the pilots of 9W 118. Due to this, the other pilot could not be reached by the German ATC - due to wrong frequency. The DGCA could not be reached to ascertain if the aircraft's cockpit voice recorder was downloaded when it reached London. While flying from Bratislava to Prague, 9W 118 was on correct frequency as it transmitted and acknowledged messages from the ATC. By this time fighter jets had been scrambled for 9W 118.

Source: Economic Times February 21, 2017 03:16 UTC