However, there does seem to be a track record of c. 5 'pilots' deciding, when temporarily alone, to crash their aircraft.
I am intrigued by the "5"? LAM, GW. EgyptAir started solo, but carried on when Capt returned. SilkAir had 2 up front. FedEx the non-pilot employee (at the time) attacked the Flt Crew. PSA the non-pilot employee shot the pilots. MH370 might be any of the above, or none.