As mentioned in another comment (https://news.ycombinator.com/item?id=27046552 https://news.ycombinator.com/item?id=27046552), it's possible the pilot chose to

As mentioned in another comment (https://news.ycombinator.com/item?id=27046552 https://news.ycombinator.com/item?id=27046552), it's possible the pilot chose to make his plane unlocatable because if it cannot be proven he intentionally downed the plane, his family would receive a payout from the airline.