On Friday, the chief executive of Malaysia Airlines, Ahmad Jauhari Yahya, was asked about reports that one of the pilots kept a flight simulator at home. “As far as pilots are concerned, everyone is actually free to do their own hobby,” he replied. “Quite a few pilots do have flight simulators at home.”

Other photos on Facebook show Mr. Zaharie cooking; he was reportedly a passionate chef.

He also curated a YouTube channel of video guides in which he affably and patiently demonstrated home maintenance tasks, including repairing the ice maker on a refrigerator and tuning air-conditioners to save money.

“He truly has a good heart,” wrote the author of a tribute page created last week for the pilot.

Less is publicly known about Mr. Fariq, who was also in the cockpit when the flight took off on March 8. According to Malaysia Airlines, he joined the company in 2007 and has logged more than 2,700 hours of flight time. A tribute page set up for Flight 370’s crew quotes his grandmother calling him “a good son, obedient, respect the elders and a pious man.” Neighbors said that he liked to play futsal, a sport similar to soccer and popular in Southeast Asia, and that he was engaged to be married, according to The Associated Press.

But Mr. Fariq’s track record has come under scrutiny in recent days after a woman, Jonti Roos, claimed that he and another captain had brought her and a friend to ride in the cockpit on a flight from Phuket, Thailand, to Kuala Lumpur in 2011. Ms. Roos provided the Australian television program “A Current Affair” with photos of her and a man she identified as Mr. Fariq.

The two women were in the cockpit from takeoff to landing, Ms. Roos said. “Throughout the whole flight they were talking to us,” she said on the program.

In his comments to reporters on Saturday, the prime minister explained how the aircraft’s communications systems were systematically disabled, perhaps by someone with intimate knowledge of the plane. He said that one system was disabled as the plane flew over the northeast coast of Malaysia, and that a second, a transponder, was disabled a few minutes later. The aircraft then altered course and flew over the Malaysian mainland before turning to the northwest and heading out to the open sea.