Asiana 777 Approached SFO Too Slowly

 - July 8, 2013, 9:47 AM
The burned wreckage of the Asiana 777-200ER that crashed Saturday lay next to Runway 28L at San Francisco International Airport. (Photo: NTSB)

The Asiana Airlines Boeing 777-200ER that crashed while landing at San Francisco International Airport (SFO) on Saturday had approached the runway at a speed “significantly below” the 137 knots targeted by the crew, according to preliminary data authorities have extracted from the airplane’s flight data and cockpit voice recorders. While briefing reporters Sunday in San Francisco, National Transportation Safety Board chairman Deborah Hersman also noted that during approach, the airplane’s idled Pratt & Whitney PW4090 turbofans appeared to respond normally to throttle command a few seconds before impact.

The airplane’s CVR recorded no discussion of any aircraft anomalies or concerns with the approach, added Hersman. One of the crewmembers did call for more engine power some seven seconds before impact, however. About three seconds later, the stick shaker activated, indicating an imminent stall, and only 1.5 seconds before impact the crew called for a go-around.

Two of the 307 passengers and crew aboard Asiana Flight 214 died after the tail of the 777 struck the sea wall at the threshold of SFO’s Runway 28L upon landing, sending it careening off the pavement and into a partial spin until it came to rest several hundred feet from the point of impact. Rescuers sent 182 of the occupants with injuries to area hospitals, some life-threatening, while 123 walked away from the wreckage.

San Francisco airport authorities managed to open three of SFO’s four runways by Sunday afternoon.

Questioned about the operation of the instrument landing system, Hersman cited a Notam (Notice to Airmen) indicating that the airport’s glideslope wouldn’t function from June 1 to August 22, while crews worked on a construction project. However, the ILS’s localizer remained in operation, and airport officials stressed that all required navigation tools at the airport worked properly at the time of the crash. Later, the FAA issued a Notam about inoperative precision approach path indicator lights damaged by the crash.

Although visual flight rules (VFR) prevailed at the time of the accident, Hersman said investigators still didn’t know whether or not the pilots opted to fly the approach entirely “by hand” or with the use of automation such as GPS-based navigation tools in the cockpit.

Comments

Chuck Bodeen's picture

No doubt the pilot pulled back on the yoke trying to gain altitude just before the crash. If he did that, it just increased the angle of attack and made the stall worst.

Richard Phillips's picture

The pilot cannot actually stall the 777 ... its fly-by-wire system includes stall and overspeed protection. It won't prevent the pilot from doing something stupid, however. Perhaps some ground proximity logic would be a good thing.

David Semak's picture

The lessons of past crashes give us safer skies, one of the lessons learned from the Colgan Air crash was retraining low hour pilots on stall avoidance. The pilot in that crash instinctively pulled up which guaranteed the fatal stall, this 777 was obviously too low to avoid the runway but the outcome may have been different if the attitude remained the same. Once the pilot pulled up he bled off any speed that he barely had enough of to begin with. I've spent some training time at Boeing with Korean pilots, they were very bright and energetic but robotic in the cockpit. Robots don't do well in emergencies.

Nicole's picture

Interesting!

Chuck Bodeen's picture

Make that "worse".

Chuck Bodeen's picture

Make that "worse".

prodromos prodromou's picture

the pilot was coming to land slow and lower so thats probably the tail hit the ground and it was to laid for go around.

art magill's picture

not hard at all, airspeed is controlled by thurst from the engines. this can be with a
pilots hand on the throttle and his eyes on the Airspeed indicator or it can be controlled by an auto signal via the auto throttles when selected "On" by a pilot.
one can then be relieved of "work" so the story goes. On the other hand one can busy himself or herself with looking out the window or?"whatever" and not notice
that the thumb switch button the auto throttles was inadvertanly deslected. You don,t notice it much in a big airplane, because you almost never fly it by attitude on the horizon, also over water, flying que,s are not attention getting, I bet that stall
warning was?, but no one practices stall recovery at low altitude on a boeing 777?!!
are they nuts. FUBAR the whole bunch. Art

art magill's picture

not hard at all, airspeed is controlled by thurst from the engines. this can be with a
pilots hand on the throttle and his eyes on the Airspeed indicator or it can be controlled by an auto signal via the auto throttles when selected "On" by a pilot.
one can then be relieved of "work" so the story goes. On the other hand one can busy himself or herself with looking out the window or?"whatever" and not notice
that the thumb switch button the auto throttles was inadvertanly deslected. You don,t notice it much in a big airplane, because you almost never fly it by attitude on the horizon, also over water, flying que,s are not attention getting, I bet that stall
warning was?, but no one practices stall recovery at low altitude on a boeing 777?!!
are they nuts. FUBAR the whole bunch. Art

Terry Herbert's picture

Well, I guess they found out that thrust is the elevator and AOA = speed.
Very sorry lesson.....if they did learn.
All could have perished with 1 knot/1 second less before the rocks.

cheers

Alex Demyanenko's picture

Cockpit resource management (CRM) training is now a mandated requirement for commercial pilots, its skills include communications, situational awareness, problem solving, decision making, and teamwork.
To see a perfectly good airplane being flown into the ground makes me think. Are these guys awake, because there not talking to each other.
Not being able to stabilize your speed on a standard approach on a beautiful VFR day is unforgiveable. The crew was lulled into a false sense of security thinking that technology will save the day, it didn’t. The scary thing is these two jet jockeys will be strapping themselves into another airplane down the road.
It happened with FLT 214, AF447 & 358, and will happen again I’m sorry to say, just hope you’re in your car when it happens.

Leo.nugroo@gmail.com's picture

The PF is an ex Airbus pilot who NEVER actually move the thrust levers. It was just the old habit kicking in thinking that the AT will take care of the speed without any throttle movement. That is normal in Airbus planes.
While in Boeing planes the throttles will actually move to reflect the AT commanded thrust.
Here we have a pilot thinking exactly the opposite to what is actually happening when the airspeed is low.
It is actually understood that trainee are expected make some mistakes. Scrutiny should be directed to the functions of the instructor and safety pilot.

abgasse's picture

On the 777 is it possible or is it procedure to put your hands on the throttles even when the AT is engaged? At least that keeps you aware of their position. It seems Airbus has left out the very important need for the pilot to feel where controls are positioned.

In the Air France 447 crash into the Atlantic out of Brazil, the First Officer could not see or feel that the Second Officer was pulling back on the side stick, thereby forcing the plane into a stall attitude. Here it seems these kinds of static controls were a contributing (but not the cause) factor. The aircraft I fly are more manual--no AT, so it is hard for me to imagine.

George Kinywa's picture

Well i heard they were 3 people in the cockpit a trainer and the 2 pilots,2 were fixed to the instruments and couldnt tell how low they were.The Captain may be had his hands folded and took the decision to lift the A/C up when it was too late.However if they could have maintained the same level then the landing gears could have caught the stonewall

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