Authorities have pointed to the shutdown of the transponders and the ACARS as evidence that someone with a detailed knowledge of the plane was involved. But Bob Coffman, an airline captain and former 777 pilot, said that kind of information is not hard to find in the digital age.
Authorities confiscated a flight simulator from the pilot's home on Saturday and also visited the home of the co-pilot in what Malaysian police chief Khalid Abu Bakar initially said were the first police visits to those homes.
But the government, which has come under criticism abroad for missteps and foot-dragging in releasing information, issued a statement on Monday contradicting that account, saying police first visited the pilots' homes as early as March 9, the day after the flight disappeared.
Coffman said the flight simulator could signify nothing more than the pilot's zeal for his job.
"There are people for whom flying is all consuming," he said, noting some pilots like to spend their off-duty hours on simulators at home, commenting on pilot blogs or playing fighter-pilot video games.
Although Malaysian authorities requested that all nations with citizens aboard the flight conduct background checks on them, it wasn't clear how thoroughly the checks were done in Malaysia. The father of a Malaysian aviation engineer aboard the plane said police had not approached anyone in the family about his 29-year-old son, Mohamad Khairul Amri Selamat, though he added that there was no reason to suspect him.
"It is impossible for him to be involved in something like this," said Selamat Omar, 60. "We are keeping our hopes high. I am praying hard that the plane didn't crash and that he will be back soon."
French investigators arriving in Kuala Lumpur to lend expertise from the two-year search for an Air France jet that crashed in the Atlantic Ocean in 2009 said they were able to rely on distress signals. But that vital tool is missing in the Malaysia Airlines mystery because the flight's communications were deliberately silenced ahead of its disappearance, investigators say.
