The captain of the doomed Malaysian Airlines Flight MH370 had ordered additional fuel to be pumped into the Boeing's tanks prior to take-off, aviation expert Larry Vance indicated in his book "MH370: Mystery Solved". The fuel would reportedly allow the plane to fly for two more hours than the planned time of the flight.
The aviation expert indicated that such a move would allow pilot, Captain Zaharie Shah, to fly the plane into the distant parts of the Indian Ocean, where he could crash it without any chances of ever being found. Vance believes that the request for additional fuel supports the theory that the pilot sent the plane into the ocean intentionally.
At the same time, the practice to pump extra fuel is sometimes used in aviation if the crew expects delays along the way to allow the plane to stay in the air long enough and then safely land. Still, it is not used all the time, since extra fuel increases an airplane's weight and hence boosts fuel consumption and flight costs in general.
Malaysia Airlines Flight MH370 with 239 passengers on board went missing on 8 March 2014, while flying from Kuala Lumpur to Beijing. After several years of unsuccessful attempts to locate the plane's remains, the Malaysian government ended its search in May 2018, admitting that they did not know what happened to the plane.