Information released by investigators thus far raises several questions, the biggest being why the Boeing 777 slowed so dramatically in the final minute of its approach. We won’t have definitive answers for some time, but we can break down how Saturday’s approach transpired and explain exactly how a modern airliner makes it to the ground — and what could go wrong.

 

There were four pilots on board the 777, which is not unusual for a transoceanic flight. Typically, one pair will sleep or relax in the crew rest bunks just behind the cockpit while the other is flying. According to the National Transportation Safety Board, the pilot at the controls was a captain in training with 43 hours in a 777 but nearly 10,000 hours in other airliners, including the Boeing 747. In addition to the flight experience, the pilot, identified as Lee Kang-kook by Asiana Airlines, also would have undergone many hours of transition training in a 777 simulator.

 

While it might sound unusual that a pilot with just 43 hours of experience would be landing the plane, it is normal, and of course necessary for pilots to fly an airplane new to them with relatively low experience in a particular type. It was first officer Jeff Skiles’ first day in an Airbus A320 when he and Captain Sully Sullenberger performed the “Miracle on the Hudson” by successfully landing in the Hudson River in 2009.