Are there lessons for pilots of comparatively small general aviation aircraft to learn from the crash of a large Boeing 777 packed with 309 people? There are, indeed, especially when the NTSB points to pilots not fully understanding complex systems and not being comfortable with basic operations such as visual approaches.
The Boeing 777-200ER was being operated as Flight 214 by Asiana Airlines on July 6, 2013, en route from Incheon Airport near Seoul, Korea, to San Francisco International Airport in California. There was a primary flight crew and a relief flight crew. The primary crew consisted of a trainee captain receiving operating experience in the 777 and an instructor who acted as pilot in command. The relief captain and first officer crew were seated in the cabin and went to the flight deck as needed. The trainee captain flew the approach to San Francisco with the instructor monitoring. The relief first officer occupied the cockpit jump seat during the approach and landing.
During a visual approach in visual conditions, the airplane struck the seawall short of runway 28L. When the main landing gear and rear of the fuselage hit the seawall, the tail broke off at the aft pressure bulkhead. As the airplane slid along the runway, it rose into the air, turned almost all the way around and hit the ground again. The right engine separated and came to rest next to the right side of the fuselage. Fire broke out in the engine, which subsequently spread to the fuselage. A flight attendant recognized that a fire was in progress outside of door number two on the right side of the airplane and started an evacuation. Initially, the instructor pilot had told a flight attendant to delay evacuating the aircraft. The airplane was destroyed by impact forces and fire. Three of the 291 passengers were fatally injured, one of whom was struck by a rescue vehicle. Forty passengers, eight of the 12 flight attendants and one of the four pilots on board received serious injuries. The other people escaped with minor or no injuries.
The flight plan showed an estimated time en route of 10 hours and 24 minutes. The trainee captain was in the cockpit for the first four hours and 15 minutes of the flight, then began a scheduled five-hour rest break in the business class section. He slept for the first two hours, but recalled having trouble sleeping and feeling tired during the remainder of the break period. He went back to the cockpit a half hour early.
The trainee told investigators he listened to the ATIS and conducted a thorough approach briefing. He was aware the runway 28L glideslope was out of service. He anticipated a visual approach to runway 28L with an approach speed of 137 knots.
The flight was given a standard arrival procedure to follow. The approach controller cleared them to the SFO VOR on a heading of 140 degrees. The flight was cleared to slow to 210 knots and maintain 9,000 feet MSL. After additional vectors and descents, the controller asked, “Asiana 214 heavy, San Francisco airport 9 to 10 o’clock, one seven miles, do you have it in sight?” The answer was affirmative, and they were cleared for a visual on an assigned heading of 310 degrees to intercept final approach. When 14 nautical miles (nm) out, they were told to maintain 180 knots until 5 nm from the airport.
The trainee said he put appropriate settings into the airplane’s autopilot system for the profile they needed to fly. However, the instructor said the navigation display predicted they would be high when crossing an intersection, and he determined they needed to lower the landing gear early to help get down. They remained above the desired glidepath. The crossing altitude was supposed to be 1,800 feet. The trainee captain set the command airspeed bug to 172 knots and acknowledged when the pilot in the jump seat pointed out that 172 was below the assigned 180 knots. The instructor told the trainee to increase the commanded descent rate to 1,500 feet per minute. The trainee captain called for 20 degrees of flaps, called for the missed approach altitude of 3,000 feet to be put into the system and then called for 30 degrees of flaps.
When the airplane was at 1,600 feet, the trainee selected the autopilot to flight level change speed mode. Because the crossing altitude of 1,800 feet had been left in the aircraft’s systems, the autopilot put the airplane into a climb. Then, the pilot disconnected the autopilot and moved the thrust levers to idle. This caused the airplane’s autothrottle system to change from the “thrust” mode to the “hold” mode. In the “hold” mode, the autothrottle system no longer controls airspeed. The trainee then lowered the nose to increase the descent rate. Neither the trainee nor the instructor noticed that the autothrottle system had gone into the “hold” mode.
The instructor said he set the command airspeed to the approach speed of 137 knots. The instructor said he saw two red and two white precision approach path indicator (PAPI) lights at 1,000 feet MSL, indicating they were on the glidepath, but speed was a little high. The pilot in the jump seat said at that time the descent rate on the vertical speed indicator was more than 1,000 fpm. He said he called out “sink rate” several times. The instructor said he heard the alert, but they were still high.
The instructor said that at 500 feet, according to the radar altimeter, the airplane was slightly low, and he saw three red and one white light on the PAPI. The trainee captain said he also saw the PAPI lights showing that the airplane was below the center of the glidepath. He told investigators he thought if he allowed the PAPI indication to go to four red lights, he would fail his flight and would be embarrassed. He said he pitched the airplane up but didn’t recall moving the throttles forward. He said he then “… saw some light and was in blindness for a second.” The instructor said he didn’t see any such light.
Recorded data showed that the airspeed went down to 118 knots as the airplane went down to 200 feet. The trainee said the pitch was 4 to 5 degrees nose up, and he believed the autothrottle should have come out of the idle position to prevent the airplane from going below the minimum speed. The instructor said when the radar altitude showed about 200 feet, he saw four red lights on the PAPI, and thought the autothrottle might not have been working.
The instructor said he heard an automated low-speed warning, “too low, too low,” but the trainee and jump seat pilot couldn’t recall hearing such a warning. However, the trainee said he saw a visual “airspeed low” or “autothrottle” message just as the instructor pushed the throttles forward and called out, “Go around.” The trainee said he added pitch to 10 degrees nose up, but that didn’t stop the airplane from sinking. The stall warning stick-shaker then activated, and the aft fuselage struck the seawall.
The 45-year-old trainee held Airline Transport Pilot certificates issued by both the FAA and the Republic of Korea’s Office of Civil Aviation. He was type rated in the Airbus A320 and Boeing 737, 747 and 777 aircraft. His Korea medical certificate was current; he didn’t need an FAA medical certificate. The trainee captain had logged 9,684 total hours, with 3,729 at pilot in command and 33 hours in the Boeing 777.
The NTSB learned that the trainee attended an Asiana Airlines ground school class in which the instructor discussed the autothrottle automation on the Boeing 777. The instructor said he told the class about his experience with the autothrottle not reengaging after unexpected activation of “hold” mode. The instructor said that he wanted to warn his students on this aspect of the B777 automation.
The Asiana B777 Chief Pilot told investigators that the airline recommended using as much automation as possible. However, he added that pilots were expected to be able to fly a visual approach without the aid of a glideslope or vertical path indicator. He said Asiana B777 pilots were well trained on visual approaches. Investigators interviewed former Asiana pilots who said they were seldom allowed to practice visual or contact approaches and preferred to fly a coupled ILS down to 1,000 feet AGL. He felt that they didn’t have the opportunity to practice the basic stick-and-rudder skills.
The Asiana B777 Pilot Operations Manual (POM) requires that, “Every flight crew member must confirm and monitor a stabilized approach. In addition, the flight crew members shall plan ahead and coordinate with ATC to avoid any abrupt maneuver on an approach. If a stabilized approach is not established, go around.”
The POM required that all approaches be stabilized by 1,000 feet AGL in instrument conditions and 500 feet AGL in visual conditions. It said that a stabilized approach is when the airplane is on the correct flight path, only small changes are required to maintain the correct flight path, the speed is no more than 10 knots above or five knots below the target speed, the sink rate is no greater than 1,000 feet per minute, the thrust is proper, the airplane is in the correct landing configuration, and all checklists and briefings have been accomplished.
The NTSB determined that the probable cause of this accident was the flight crew’s mismanagement of the airplane’s descent during the visual approach, the trainee’s unintended deactivation of autothrottle control, the crew’s inadequate monitoring of airspeed and their delayed execution of a go-around. Among the contributing factors were the complexities of the autothrottle and autopilot flight director systems, inadequate training of the trainee on planning and executing visual approaches, the instructor’s inadequate supervision, and flight crew fatigue.
Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, N.Y. 10602-0831.