NTSB Hearing Reveals Details of Asiana 214’s Final Approach

 - December 16, 2013, 3:15 PM
NTSB last week held hearings into the July 6 crash of an Asiana Airlines Boeing 777 at San Francisco International Airport.

During hearings on December 11, National Transportation Safety Board officials described the final approach sequence of Asiana Airlines Flight 214, which crashed at San Francisco International Airport on July 6. The Boeing 777 was cleared for a visual approach to Runway 28 Left where, as per a Notam, the glideslope was inactive. The left-seat pilot flying had logged fewer than 45 hours in the 777, while the right-seat instructor had 3,200 hours of time on the widebody.

On a 15 mile final approach, the Boeing’s airspeed was at 210 knots as it descended with autopilot and flight-level change (FLCH) engaged. Descent altitude was set at 1,800 feet. The aircraft was high on final approach and switching to vertical speed mode did not help this situation. Final approach reference speed was calculated at 137 knots. On a five-mile final the altitude was reset to 3,000 feet in case of a go-around. At 1,600 feet and 3.5 miles from the runway, the FLCH switch was again activated, which changed the autothrottle mode. [Boeing does not recommend using FLCH inside the final approach fix—Ed.].

When the FLCH was engaged, the autopilot tried to climb the airplane to 3,000 feet. The pilot reacted by pulling the thrust to idle and disconnecting the autopilot. This put the autothrottles in hold mode at idle. At 1.4 miles from the runway and at 500 feet above the water the aircraft was still descending. With the thrust at idle, the left-seat pilot began to add backpressure to the control wheel to stop the descent and get back on the visual glideslope from the precision approach path indicator.

The airspeed continued to decay–now slowing through 120 knots–although neither pilot mentioned it. Eleven seconds before impact a low-speed alert was heard in the cockpit. At eight seconds from impact and with the aircraft 100 feet above the water, the pilots moved the throttles full forward to initiate a go-around. Four seconds later the stick shaker activated and someone in the cockpit called for a go-around. The action was too late and the main gear and aft fuselage struck the seawall. The lowest recorded airspeed was 103 knots, 34 knots below the calculated safe reference speed.