Learning from failure

Mahabubul AlamCS/SE 6361, Fall 2014 Term Paper Presentation – I The University

of Texas at Dallas

Asiana Airlines #214

The Incident

At 11:28AM PDT, The Boeing 777-200ER crashed short of runway 28L’s threshold while attempting to land at SFO. The Fuselage separated from the tail & engine and spun 330 degrees before coming to rest 2,000 feet away.There were 3 Fatalities &

187 Injured.

The weather was very good and there were no mechanical failures

On July 6, 2013 Asiana Airlines Flight 214, carrying 291 passengers and 16 crew members Left Incheon International Airport at 5:04PM KST for San Francisco International Airport.

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How it happened

While attempting to land, the tail of the aircraft hit the seawall at the end

of the runway. 2

Why it happened?

The Aircraft was coming in too low and too slow.

An Uneven Descent

Same Flight on Previous days

Source: NTSB, FAA 3

Why the uneven descent?

The critical events leading up to the crash

Source: NTSB, FAA

*Based on the weight and configuration of the 777-200ER on Saturday, the reference landing speed was 137 knots. **Auto Throttle in B777 requires to be armed and engaged. It was found to be armed only.

11:21AM Flight 214 cleared for a visual approach for runway 28L.

T-3m, 4000ft A vertical descent of 1,500ft/m was set. Auto throttle set to idle.

T-82s, 1,600ft

The Flight Director was turned off.

T-54s, 1,000ft

The airplane had slowed to 149 knots.

T-34s, 500ft The airplane had slowed to 149 knots, Auto throttle not maintaining speed.**

200ft The airspeed had slowed to 118 knots.*T-11s Audible alarm – Airspeed too low.T-8s, 125ft The throttles began moving forward, Airspeed 112

Knots.T-3s, 103ft First Call for a Go Around.T-1.5s Second Call for Go Around.11:28AMImpact

The 777 impacted the ground at 106 knots — 122 mph — and at least several hundred feet shy of the runway touchdown zone.

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Who/ What failed?

Depends on who you ask

Automation Confusion5

The Boeing 777

Source: Boeing, FAA

• First Boeing designed with Fly-by-wire Technology.

• Costs US $ 260-320 Million.

• 1,239 Aircraft Delivered.

• 18 Years of Service.

• 5 Million Flights vs 2 crashes.

• 512 Boeing 777s in the air when OZ214 crashed.

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The Pilots

Source: NTSB & Asiana Airlines

• Training Captain with 12,387 hours Flying (3,220 hours in B777).

• First Flight as a Trainer.

• Trainee Captain (in Command) with 10 years of Single isle Airbus 320 Flying.

• 43 hours in a B777. 9,793 hours total Flying experience.

• First Landing at San Francisco in a B777.

• Found Visual Approach* very Stressful.

• Thought Auto was working until too late.*The tower may have requested that the pilots make a visual approach as a result of the airport's Instrument Landing System (ILS) not functioning at the time of the landing. 

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…transitioning from Airbus to Boeing

Source: Wikipedia

AirbusAutopilot Imposes Hard

Limits on Pilots

BoeingPilot Always retain Ultimate

Authority

A Boeing 777 Cockpit with Yokes An Airbus A320 Cockpit with Joysticks

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Caught in the “FLCH Trap”?

Source: NTSB & Asiana Airlines

• Used FLCH (Flight Level Change) to start descent.

• Retarded the throttle levers.

• Set Flight Director off for a Visual Approach.

• Expected Auto Throttle to provide low speed protection.By design, the FLCH mode allows the auto thrust system to enter into a “hold” or “sleep” state

during descents if pilots manually move the throttle levers for more than 1.2 sec.

For practically all other auto flight modes, the auto throttle will reengage, or “wake up” and command

thrust if speeds get too low.

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The NTSB Ruling -

Source: NTSB

• Probable Cause

• Crew Mismanagement of Decent During Visual Approach.

• Inadequate Monitoring by Crew of Airspeed, and delayed call for go-around.

• Pilot’s unintended deactivation of Air speed Control.

• Contributing Factors

• Inadequate description by Boeing of aircraft system complexities.

• Asiana’s inadequate flight system & visual approach training.

• Inadequate supervision of pilot by monitoring pilot.

• Crew Fatigue.

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A Lack of Usability & Understandability

• The interaction between the 777's auto-flight and auto-thrust modes.

• Audible Warning only 11 second before impact?

• Auto Throttle and Go-Around – Both Require 2 Steps.

• Not enough Transition Training?

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References

Asiana Airlines Flight 214http://en.wikipedia.org/wiki/Asiana_Airlines_Flight_214

Crash of Asiana Flight 214 Accident Report Summaryhttp://www.ntsb.gov/news/events/2014/asiana214/abstract.html

NTSB: Asiana crew 'over-relied' on automated systemshttp://www.usatoday.com/story/travel/news/2014/06/24/ntsb-asiana-fatal-crash-san-francisco/11302347/

Pilot in deadly plane crash had no experience landing 777 in San Franciscohttp://www.cnn.com/2013/07/07/us/plane-crash-main/

Asiana Flight 214 Investigation Focuses on Airspeed in Final Secondshttp://www.wired.com/2013/07/ntsb-wraps-up-asiana-214/

Asiana cites crew failures and autothrottle design in flight 214 crashhttp://www.flightglobal.com/news/articles/asiana-cites-crew-failures-and-autothrottle-design-in-flight-214-397632/

Retired Senior Boeing Flight Instructor blames on the Auto-throttle Systemhttp://www.cockpitchatter.com/retired-senior-boeing-flight-instructor-blames-on-the-auto-throttle-system/

Statistical Summary of Commercial Jet Airplane Accidentshttp://www.boeing.com/news/techissues/pdf/statsum.pdf

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