BOEING 737 MAX 8 PLANE CRASHES

Case History

June 20, 2019 Steering Committee Meeting

Trent Parker

2nd Year PhD Student

Purpose

❑ Boeing 737 MAX 8 Crashes Serve to Illustrate 7 OSHA

Process Safety Management1 Principles:

– Employee Participation

– Process Safety Information

– Operating Procedures

– Management of Change

– Training

– Mechanical Integrity

– Incident Investigation

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Overview

❑ Two major crashes investigated

❑ Plane type: Boeing 737 MAX 8

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Crash #1 Crash #2

Date October 29, 2018 March 10, 2019

Aircraft Registration PK-LQP ET-AVJ

Flight 610, Lion Air 302, Ethiopian Airlines

Crash Location Java Sea, Indonesia Bishoftu, Ethiopia

Fatalities 189 (All Aboard)2 157 (All Aboard)2

Background

❑ Boeing 737 and Airbus A320 are largest competitors,

comprising nearly half of world’s commercial airplanes

❑ On December 10, 2010, Airbus released new version of

A320 secretly developed, the A320neo (new engine option)

❑ A320neo consumed approximately 6% less fuel than A320

❑ More A320neos sold during week of 2011 Paris Air Show

than 737s sold in all of 2010

❑ Boeing determined best course of action was to develop and

launch fourth generation 737

❑ 737 MAX 8 was to be designed to counter the challenge of

A320neo3

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Background

❑ Prototype of 737 MAX 8 developed

❑ MAX designed to be 8% more fuel efficient than Airbus’s

A320neo

❑ Amended Type Certificate issued by FAA for 737 MAX 8,

resulting in common type certifications for all 737 models

❑ $200 billion in 737 MAX 8 aircraft sold before first

prototype was flown2

❑ First 737 MAX 8 delivered on May 6, 2017

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Lion Air Flight 043 (PK-LQP)

❑ October 28, 2018, just after takeoff, stick shaker on captain’s

side began to vibrate, warning to reduce angle of attack (AoA)

❑ IAS DISAGREE shown on flight display (Indicated Airspeed)

❑ Aircraft contained three systems working in parallel, two

primary and one backup

❑ Captain passed control of aircraft to first officer

❑ Captain found left side instruments to be receiving bad data,

so switched primary displays to use data from right side

instruments

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Boeing 737 MAX 8

Stick Shaker

Lion Air Flight 043 (PK-LQP)

❑ Once aircraft reached 1500 feet, initial takeoff of flight

was complete

❑ First officer began initial climb (adjusted throttle, set

climb slope, and retracted flaps)

❑ Aircraft lurched downward rather than climb

❑ First officer flipped electric trim switch and pulled control

column back to counteract dive and plane responded,

before diving again five seconds later

❑ Process repeated over a dozen times in the six minutes

that followed

❑ Captain struggled to find correct checklist, and off-duty

pilot in cockpit suggested runway stabilizer checklist

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Lion Air Flight 043 (PK-LQP)

❑ Runway stabilizer checklist followed and STAB TRIM

switches flipped to CUT OUT on center console,

disabling MCAS

❑ Successful in stopping aircraft from pitching down for

remainder of flight

❑ Aircraft successfully landed in Jakarta, Indonesia

❑ Airline’s maintenance team checked for serious

equipment failures, and found none3

8

Lion Air Flight 610 (PK-LQP)

❑ October 29, 2018, aircraft PK-LQP began takeoff

❑ Stick shaker began to vibrate, and multiple errors shown

on flight display

❑ After flaps were retracted, aircraft lurched downward

❑ Captain flipped electric trim switch and pulled control

column back to counteract dive and plane responded,

before diving again soon after

❑ Process repeated 28 times over the course of eight

minutes

❑ Aircraft lurched downward one last time, plunging into

Java Sea and killing all (189) aboard4

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Lion Air Flight 610 Telemetry3

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Altitude Airspeed

Altitude (

ft)

Airspeed (

mph)

Initial Takeoff

6:21 am

Aircraft Crash

6:32 am

Incident Response

❑ Boeing released bulletin on MyBoeingFleet, including the

following statement3:

❑ Bulletin described series of events that occurred before

PK-LQP crashed

❑ STAB TRIM switches were to be switched to CUT OUT

in response to sudden dives, as Lion Air Flight 043 crew

had done5

❑ No mention of name of system involved in sudden dives

❑ Four days later, more detailed information released

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Engine Placement Changes

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❑ New engines (LEAP-1Bs) much larger/heavier6

❑ Problem: Too little ground clearance (18 in.) if mounted

at same location on wing

❑ Solution: Mount further forward relative to wing and

slightly higher on wing

737NG Engine Placement LEAP-1B Engine Placement

Engine Placement Changes

❑ Placement change resulted in greater lift for airplane

entering steep climb (high angle of attack)

❑ Different handling than previous 737 models, but only for

high AoA

❑ Problem: FAA would assign MAX 8 its own type rating,

incompatible with previous 737 models. Pilots would have

to be trained specifically to fly MAX 8.

❑ Solution: Implement Maneuvering Characteristics

Augmentation System (MCAS)

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MCAS Fundamentals

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1) AoA sensors in nose measure angle of flight

2) Horizontal stabilizer trim adjusts to correct angle if too high

1

2

Company Response to Lion Air Crash

❑ Boeing claimed pilots should never see operation of

MCAS, and FAA had agreed

❑ Thus, FAA had allowed description of MCAS to be

removed from pilot’s manual7

❑ Many pilots disagreed with decision, believing they

should have information on all components of aircraft8

❑ Boeing sent representatives around world to rebuild

confidence in 737 MAX 8

❑ Lion Air successfully talked out of canceling $5 billion

order

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Ethiopian Airlines Flight 302 (ET-AVJ)

❑ March 10, 2019, aircraft ET-AVJ began takeoff

❑ Stick shaker began to vibrate, and altitude and AoA sensors

on one side of aircraft malfunctioned

❑ After flaps were retracted, MCAS activated and aircraft

lurched downward

❑ Ground Proximity Warning System alerted: DON’T SINK.

DON’T SINK.

❑ Captain pulled control column back to counteract dive, and

flicked electric trim switch, momentarily disengaging MCAS

❑ MCAS reactivated, and captain again pulled up on column

and flicked switch9

❑ Process was repeated each time a few hundred feet of altitude

were gained16

❑ First officer called out to captain to switch STAB TRIM

switches to CUT OUT, and captain complied

❑ Aircraft traveling at 400 mph, well past its redline

❑ Aircraft was very difficult to control, and pulling control

column up resulted in little aircraft response

❑ Crew reactivated MCAS, believing

it would return aircraft to climb

❑ Aircraft lurched downward at over

575 mph and crashed into a field

near Bishoftu, Ethiopia, killing all

(157) aboard10

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Ethiopian Airlines Flight 302 (ET-AVJ)

FAA Type Certificate Documentation

❑ FAA delegates much of certification process to

manufacturers themselves, through “designee program”

❑ “Potential conflict of interest” present, as employees do work

for FAA while being paid by industry regulated by FAA

❑ FAA reviewed certification documents from Boeing, but

conducted “rushed review” to meet certain certification dates

to allow Boeing to release MAX 8 as scheduled

❑ FAA listed where the 737 MAX 8 did and did not differ from

other models with same type certificate

❑ List was more than 30 pages, including such aspects as

engine noise, seat belts, and aluminum fatigue

❑ However, MCAS was listed nowhere in document11

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FAA Failure Condition Review

❑ FAA assigned MCAS “hazardous failure” designation in

certification review

❑ MCAS malfunction would result in, at worst, “a large

reduction in safety margins” or “serious or fatal injury to a

relatively small number of the occupants”

❑ FAA regulations require at least two levels of redundancy,

with chance of failure less than 1 x 10-7 for this designation

❑ Final version of MCAS did not meet either of these

standards11

❑ FAA regulators had not conducted formal safety assessment

of final version of MCAS7

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FAA Standards Noncompliance

❑ Prototype MCAS relied on data from two types of sensors7

❑ However, final version of MCAS had no redundancy, taking

input from one AoA sensor at a time

❑ This prevented MCAS from coping with sensor malfunctions

❑ 50 flights experienced AoA sensor issues over five years

(One failure per 1.7 million commercial flight-hours)

❑ Prototype MCAS could move horizontal

stabilizer only 0.6° at a time, triggered in

rare conditions

❑ However, final version of MCAS could

move stabilizer up to 2.5° at a time2,

operating during much more of the flight7

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FAA Risk Specifications3

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Normal

Nuisance

Abnormal

Procedures

Emergency

Procedures

Aircraft Damage

Adverse Effects

on Occupants

Catastrophic

Incident

Probable(1 x 10-5)

Improbable(1 x 10-7)

Extremely Improbable

(1 x 10-9)

Probability of Failure Condition

Co

nse

qu

ence

of

Fa

ilu

re C

on

dit

ion

Unacceptable

Acceptable

AoA Sensor

Aftermath of Crashes

❑ All 737 MAX 8 aircraft (30) grounded by FAA on March 13,

201912

❑ 346 lives lost in total

– 189 on Lion Air Flight 610

– 157 on Ethiopian Airlines Flight 302

❑ Up to $1 billion in costs associated with grounding

❑ By March 23, 2019, Boeing stock lost 18% of value ($40

billion drop in market capitalization)

❑ Over $30 billion in aircraft orders airlines have threatened to

cancel13

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Future of 737 MAX Aircraft

❑ Boeing reworking MCAS to more closely resemble first

version7

❑ No orders placed for Boeing aircraft for approximately

three months, including first day of 2019 Paris Air Show

❑ On June 18, 2019, International Airlines Group (IAG)

signed letter of intent for 200 Boeing 737 MAX aircraft at

2019 Paris Air Show14

– Combination of MAX 8 and MAX 10 aircraft

– Planned delivery between 2023 and 2027

❑ No date currently set for 30 grounded MAX 8 aircraft to

return to service

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Recommendations

❑ Redundancy of components is critical

❑ Near-misses should be thoroughly investigated to determine

root cause, with corrective actions taken

❑ Effective management of change should occur when any

changes are made to equipment, in accordance with

applicable regulations

❑ Employees should be trained on any changes made to

equipment or processes

❑ Employees should be actively involved in assessments and

implementation of equipment and processes

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Recommendations

❑ Easily accessible, well-defined checklists should be

provided for any situations that may arise

❑ Thorough, well-written, prescriptive operating procedures

should serve to train employees and supplement

information presented in the checklists

❑ Comprehensive safety assessments of all versions of

equipment should be conducted, with no assumptions of

similarities

❑ When equipment certification and safety assessments are

conducted, no conflicts of interest should be present

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References

[1] UNITED STATES DEPARTMENT OF LABOR. (n.d.). Retrieved from

https://www.osha.gov/SLTC/processsafetymanagement/standards.html

[2] Hough, J., & Hough, J. (2019, March 16). Fallout from the Boeing 737 MAX 8 Crash

Could Last for Years. Retrieved from https://www.barrons.com/articles/fallout-

from-the-boeing-737-max-8-crash-could-last-for-years-51552694400

[3] Campbell, D. (2019, May 02). The many human errors that brought down the Boeing 737 Max.

Retrieved from https://www.theverge.com/2019/5/2/18518176/boeing-737-max-crash-

problems-human-error-mcas-faa

[4] Boeing 737 Max: What went wrong? (2019, April 05). Retrieved from

https://www.bbc.com/news/world-africa-47553174

[5] Grinberg, E. (2019, May 07). Boeing knew about problems with the 737 Max the year

before Lion Air crash and did nothing about them. Retrieved from

https://www.cnn.com/2019/05/05/us/boeing-737-max-disagree-alert/index.html

[6] Axios. (2019, May 14). Everything you need to know about the Boeing 737 MAX crashes.

Retrieved from https://www.axios.com/boeing-737-max-crash-what-know-a5087b8e-1787-

4de5-bece-d1350d5695cf.html

[7] Nicas, J., Kitroeff, N., Gelles, D., & Glanz, J. (2019, June 01). Boeing Built Deadly

Assumptions Into 737 Max, Blind to a Late Design Change. Retrieved from

https://www.nytimes.com/2019/06/01/business/boeing-737-max-crash.html

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References

[8] Helmore, E. (2019, May 23). American Airlines union: Blaming pilots for Boeing 737

Max crashes 'inexcusable'. Retrieved from https://www.theguardian.com/business/

2019/may/23/boeing-737-max-crashes-american-airlines-pilots-union-mcas

[9] At Boeing, the Flap Over One Tiny Light Indicates Much Larger Flaws. (n.d.). Retrieved

from http://fortune.com/2019/05/20/at-boeing-the-flap-over-one-tiny-light-indicates-

much-larger-flaws/

[10] Stewart, E. (2019, April 04). Preliminary report on Ethiopia crash finds pilots followed

Boeing's procedures properly. Retrieved from https://www.vox.com/policy-and-

politics/2019/4/4/18295528/boeing-737-max-ethiopia-faa-dagmawit-moges

[11] Blum, S. (2019, April 04). Boeing Takes Full Responsibility For Two Plane Crashes That

Killed 360 People. Retrieved from https://www.popularmechanics.com/flight/airlines/

a27047293/boeing-apology-737-max-8-crashes/

[12] Darrah, N. (n.d.). FAA grounds Boeing 737 Max 8, 737 Max 9 planes following deadly

Ethiopian Airlines crash. Retrieved from https://www.foxnews.com/politics/trump-says-faa-

will-ground-boeing-737-max-8-737-max-9-planes-following-deadly-ethiopian-airlines-crash

[13] Chicago Tribune. (2019, May 14). Timeline: Boeing 737 Max jetliner crashes and aftermath.

Retrieved from https://www.chicagotribune.com/business/ct-biz-viz-boeing-737-max-crash-

timeline-04022019-story.html

[14] Meredith, S. (2019, June 17). Boeing CEO says the safe return of its 737 Max aircraft is 'most

important'. Retrieved from https://www.cnbc.com/2019/06/17/boeing-ceo-says-the-safe-

return-of-its-737-max-aircraft-is-most-important.html

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Questions or Comments?

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