At 00:42:40, after MH370 confirmed it had taken off successfully, air traffic control instruct the plane to fly towards “Igari”, a waypoint halfway between Malaysia and Vietnam.
After leaving the airports control tower range, MH370 is instructed to change the frequency to that of the Malaysian air traffic controller.
“132.6, MH370 copies that,” it states at 00:42:52.
The next 20 minutes is fairly normal communication, with air traffic control giving the cockpit permission to ascend to an altitude of 25,000 feet and then 35,000 feet.
The first unusual moment occurs at about 1:07 when the cockpit advises that, “MH370 remaining in flight altitude 350 (35,000 feet),” an unnecessary call that had already been spoken six minutes earlier.
This is a pivotal moment for flight MH370, happening about the same time as the plane's ACARS signalling device sent its last message before it was, according to reports, deliberately switched off.
Air traffic control contacted MH370's cockpit 21 minutes later saying “MH370, please contact Ho Chi Minh City 120.9, good night,” telling the pilots to now change frequencies to Vietnam's air traffic controller. A change that never happened.
“All right, good night,” the cockpit responded in its final words before disappearing.
This is also considered odd communication, with the final call spoken in a more relaxed manner than usual when changing to a new air traffic controller.
It also happened at the same time the plane took a sharp turn off its flight course.
