New research suggests the plane took an unexplained U-turn and headed back across the Malay Peninsula before vanishing

One theory put forward by electrical engineer Mike Exner, from Colorado, is that the pilot probably made a climb which “accelerated the effects of depressurising, causing the rapid incapacitation and death of everyone in the cabin.”
With oxygen still available in the cockpit, Mr Ahmad Shah could have kept flying for hours.
The Australian Transport Safety Bureau’s (ATSB) $200 million search for MH370 scoured more than 120,000sq km of Indian Ocean floor using high-resolution sonar between 2014 to 2017 but could not locate the plane.
A second search sponsored by the Malaysian government was also fruitless.
In its final report, the ATSB identified an area of less than 25,000sq km “which has the highest likelihood of containing MH370”.
While the aircraft has not been located, 33 pieces of debris either confirmed or highly likely to be from MH370 have been discovered in Mauritius, Madagascar, Tanzania and South Africa.