At 12:41am, on March 8, 2014, Malaysian Airlines Flight 370 takes off from the Kuala Lumpur International Airport, seemingly without any issues. The plane was heading to the Beijing Capital International Airport.
40 minutes after takeoff, the flight was flying at a normal cruising altitude of 35,000 feet. The two men in the cockpit  check in regularly with air traffic-control and didn’t report anything unusual. Then, all systems onboard seemingly malfunction and communication with the flight is lost.
And after missing its scheduled arrival time in Beijing, 4 hours later, Flight 370 and all 239 people onboard are officially declared missing.


References

https://www.youtube.com/watch?v=kd2KEHvK-q8

https://www.abc.net.au/news/2014-03-19/tracking-flight-mh370-acars-and-transponder/5331124?nw=0

https://www.google.com/search?rlz=1C5CHFA_enIN874IN874&sxsrf=ALeKk02Rq1ELXYC3hzEReyx2xJBnYKMuEw%3A1609837415776&ei=Zyv0X933LsO_8QPJyYzQDA&q=normal+speed+of+aeroplane&oq=normal+speed+&gs_lcp=CgZwc3ktYWIQARgBMgoIABDJAxAUEIcCMgIIADICCAAyAggAMgIIADICCAAyAggAMgIIADICCAAyAggAOgQIABBHOgQIIxAnOgoILhDHARCvARAnOgUIABCRAjoFCAAQsQM6AgguOggILhCxAxCDAToICAAQsQMQgwE6BAgAEEM6BQguELEDOggIABDJAxCRAjoHCC4QsQMQQzoHCAAQyQMQQzoICAAQsQMQyQNQ_0RYvG1gg3poAHAEeACAAYQBiAHsCpIBAzUuOJgBAKABAaoBB2d3cy13aXrIAQjAAQE&sclient=psy-ab

https://www.traveller.com.au/pilots-reveal-the-greatest-myth-about-being-an-airline-captain-h0vxdb

https://www.aeroprofessional.com/what-does-it-feel-like-to-fly-the-b777-the-aircraft-that-transformed-the-skies/

https://www.businessinsider.in/tech/article/how-does-autopilot-work-on-a-plane/articleshow/72181132.cms

https://www.abc.net.au/news/2015-07-31/mh370:-what-is-washed-up-plane-debris-flaperon/6663434

https://www.theguardian.com/world/live/2018/jul/30/mh370-final-report-released-by-malaysian-government-live

https://www.cbs19.tv/article/news/key-moments-emerge-in-tracking-of-missing-malaysia-airlines-plane/501-266319638
https://www.theguardian.com/world/2017/jan/17/mh370-pilot-sister-my-brother-loved-life-zaharie-ahmad-shah

https://www.youtube.com/watch?v=yN7GRoCgrAE

https://www.youtube.com/watch?v=n_yR7uz2ftE