The pilot and co-pilot told authorities that he entered the cockpit while they were performing their preflight duties and checks and said he was a Boeing 747 pilot, officials said.
"It is easy to imagine that some of these interruptions could have led to forgetting of steps, including checking the fuel level, performing the preflight, " said Bill Bramble, an NTSB aviation expert.
Hiring people with the scientific training to regulate the preflight temperature and water purity and to control waste during transit is the only solution, say experts such as John Neo, who heads aquarium-gear supplier Ehaim Asia.