16.400/453j human factors engineering - … factors evaluation 16.400/453 • each student is to...

16.400/453J Human Factors Engineering

Introduction Professor Larry Young

Professor Divya Chandra Caroline Lowenthal

1

Outline 16.400/453

• Introductions • Human Factors Evaluation • Syllabus • Overview of Human Factors • Case study presentation • Questions

2

Human Factors Evaluation 16.400/453

• Each Student is to choose a Human Factors example and write down: – Some HF Issue (what is difficult or dangerous) – A potential solution to the problem – And what you would need to know to design a good solution.

– Put YOUR NAME and contact info on the card – They will be collected at the end of the case study presentation

3

Syllabus 16.400/453

• Books – Proctor, R. W., & Van Zandt, Dismukes, et al., Bluman, A.G

• Readings • Case studies

– Presentations • Online surveys (Daily Quizzes) • P‐sets (2) & Projects (3 UG +1 G) • Quizzes • Grad students

4

/453

5

Overview of Human Factors 16.400

Schematic representation of a human-machine system.

Input Output

InformationProcessing

Controlling

Sensing

ControlsDisplay

Operation

Human BeingHuman BeingHuman Being

MachineMachineMachine

Work Environment

Image by MIT OpenCourseWare.

Case Study Presentation 16.400/453

6

Eastern Airlines Flight 401 Larry Young

7

Flight Summary

• Lockheed L‐1011 Tristar • Departed NY(JFK) ‐> Florida(MIA) 9:20pm, Dec29th, 1972

• Crashed 11:42pm ~18 miles from MIA • 103/176 People on board died in the crash. • Cause of the accident (NTSB):

– Failure of crew to monitor instruments during final 4 minutes of flight, leading to CFIT

– Distraction while dealing with failure of nose landing gear position light is a contributing factor

8

Lockheed L‐1011 Tristar

• Competitor of the DC‐10 • Triple‐engine configuration, 400

passengers max. • Between 1968 and 1984,

Lockheed manufactured a total of 250 TriStars.

• The L‐1011 was advertised technologically largely ahead of its time.

• First widebody to receive FAA certification for Cat‐IIIc autolanding (no decision height,zero visibility).

This image is in the public domain. Source: NASA

9

L‐1011 Overview • Direct Lift Control (DLC) system which allowed for smooth

approaches when landing. • Four redundant hydraulic systems (the DC10 and MD11

had only three). • As of September 2006, 33 are in service with ad hoc

charter and military carriers, as well as Hewa Bora Airways of the Democratic Republic of Congo, the sole remaining operator of scheduled TriStar flights.

• Most remaining L‐1011’s are now being sold for scrap.

• There has never been a crash of an L‐1011 due to mechanical failure.

10

Flight Narrative

• The flight crew was qualified, with >40,000 flight hours between the Captain and the First Officer.

• There was an experienced Flight Engineer, and a maintenance officer in the cockpit as well.

• The flight was essentially uneventful leading up to the approach to MIA.

• During the approach, the landing gear handle was lowered, but only 2/3 gear could be confirmed to be in the down position (via the cockpit indicator lights).

11

L‐1011 Cockpit

Images of Lockheed L-1011 cockpit removed due to copyright restrictions.

12

Images of Lockheed L-1011 cockpit removed due to copyright restrictions.

13

Flight Narrative • Unsure of whether the gear or the indicator was at fault, the Captain elected to abort the landing.

• The flight was directed by ATC to 2000ft and was given a course to hold while diagnosing the problem.

• The autopilot was engaged to hold course and altitude.

• The Captain ordered the F/O to fly the plane while he communicated with ATC and coordinated with the Flight Engineer to diagnose the problem.

14

Flight Narrative • Upon reporting that the hydraulics were online, the Flight

Engineer was ordered down into the “hell hole”. • The copilot pulled out the suspect light, inspected it, and

jammed it back in the panel incorrectly.

• Captain: You got it sideways, then. Co-pilot: Naw, I don't think it'll fit. Captain: You gotta turn it one quarter turn to the left. Captain: Hey, hey, get down there and see if that damn nose wheel's down. You better do that. Co-pilot: You got a handkerchief or something so I can get a little better grip on this? Anything I can do with it? Captain: Get down there and see. Co-pilot: This won't come out, Bob. If I had a pair of pliers, I could cushion it with that Kleenex. Flight Engineer: I can give you pliers but if you force it, you'll break it, just believe me Co-pilot: Yeah, I'll cushion it with Kleenex

15

Flight Narrative • At 11:40:38 a C‐chord was heard in the CVR, indicating a 250ft deviation from the selected altitude. This was apparently missed by the flight crew.

• Co-pilot: Naw that's right, we're about to cross Krome Avenue right now.

[Sound of click] Co-pilot: I don't know what the # holding that # # # # in' Co-pilot: Always something, we coulda make schedule'

[Sound of altitude alert] Captain: We can tell if that # # # # is down by looking down at our indices Captain: I'm sure it's down, there' s no way it couldnt help but be Co-pilot: I'm sure it is

16

Flight Narrative

• The Flight Engineer in the hole reported that he couldn’t see the gear through the viewing periscope, as it was too dark.

• The maintenance officer riding in the jumpseat attempted to help, but also couldn’t see anything.

• The problem was discussed for another 30s before it was decided to turn back to the airport.

17

Flight Narrative • Air traffic controller: Eastern, ah 401 how are things comin'

along out there? Capt to air traffic controller: Okay, we'd like to turn around and come, come back in. Captain: Clear on left? Co-pilot: Okay Air traffic controller: Eastern 401 turn left heading one eight zero Co-pilot: We did something to the altitude ' Captain: What? ' Co-pilot: We 're still at two thousand right?' Captain: Hey, what's happening here? '

[Sound of click] [Sound of six beeps similar to radio altimeter increasing in rate] [Sound of impact]

18

19

Flightpath, 29 DEC 1972, Eastern TristarEverglades, FL

Miami InternationalAirport

RWY 09L

Glide slope

182 kts179 kts

176 kts

176 kts

170 kts

180 kts

Pitch CWSRoll CWS orhead sel.

Pitch CWSRoll CWS orhead sel.

240o

KROME AVE

1900FT.

2000FT.


Investigation • Examination of the wreckage showed that the indicator bulb had been burned out, and that the gear was operational

• It was speculated that the pilot may have inadvertently bumped the control column, disengaging the autopilot from its altitude‐hold mode, and that this went undetected by the flight crew

• The altitude had gradually decayed over a period of minutes before impact

20

HF Issues

• Poor Crew Resource Management (CRM) • Failure to maintain task priority: “Aviate, Navigate, Communicate”

• Overreliance on Automation, leading to loss of situational awareness

• Excessively cluttered and complicated cockpit layout

21

Possible Solutions

• CRM training • Simplified cockpit design (glass?) • Improve training emphasizing aviate first • More intelligent automation:

– Better alarm for autopilot disengage

22

References • NTSB:AAR 73‐14. 14 JUN, 1973. Retrieved 5 Sep, 2006, from

http://www.ntsb.gov/ • “Eastern Airlines Flight 401 Memorial”. Retrieved 5 Sep, 2006,

from http://eastern401.googlepages.com/

Questions?

23

http://eastern401.googlepages.com/

http://www.ntsb.gov/

Syllabus Overview 16.400/453

• Introduction and Vision I • Automation, Situation Awareness • Vision II • Decision Making • Space Bioastronautics • Flight Deck Automation Working • Research Methods I Group

• Research Methods II • Manual Control I

• Vestibular/Spatial Disorientation • Manual Control II, FAA Regulations

• Displays • Fatigue/Circadian Rhythms

• Space Human Factors • Automobile HF

• Auditory • Response Selection & Control of Movement • Attention/Workload

• Anthropometry/Environmental • PIO and Cooper Harper Ergonomics

• Handling Qualities • Volpe HF Lab Tour

• Space Physiology

24

Human Vision and Aircraft Displays

Part 1 The Eye

16.400/16.453J Prof. L. R. Young

25

26

θθ

Aircraft B

Impact

Aircraft A

Relative bearing

Aircraft about to collide will remain at constant relative bearings. (i.e there will be no movement across the windshield)


27

0.1 s/very big indeed

0.38 s/4o

0.75 s/2o

1.5 s/1o

3 s/ 12/o

The retinal size of an approaching aircraft before impact.


28

Conjunctiva

Ora serrata

Ciliary body

Aqueous

Anterior chamberCorneaPupilLens

Posterior chamber

Canal of schlemm

Conjunctiva

Iris

Rectus medialis

Vitreous

Sclera

Choroid

Retina

Macula

Artery (central retinal)

Optic nerve

Vein (central retinal)


Eye Movements

• Tracking • Vergence (Versional) • Compensatory – Saccades (VOR) – Pursuit • Nystagmus

• Miniature Drift Flicks Tremor

29

30


31

Retina Organization

Pigment epithelium

Rods

Cones

Muller cellsOuter limiting membrane

Horizontal cells

Bipolar cells

Amacrine cells

Ganglion cells

Nerve fiber layerInner limiting membrane


32

Thre

shol

d

Thre

shol

dConesRods

Rods (Color insensitive, Max. concentration at 20o)Cones (Color sensitive, Max. concentration at 0o)

Foveal Acuity ~ 1 Min. of arc

Max. Lumens - Sun (threshold of damage)Min. Lumens - A few photons (Min. threshold)Ratio of above ~ 1013

Frequency range 340 - 760 nm wavelengthColor adaption - "Visual purple"Temporal adaption - Flicker fusion 20 H

- 20 Min. in dark.

Light - Sensitive Transducers :

Wavelength Time in Dark

z


33

Angular Eccentricity - Degree

Num

ber

of R

ods

or C

ones

- T

hous

ands

/ m

m2

0

50

100

100 80 60 60 8040 4020 200

150

200

Nasal Retina (Temporal Field) Fovea Temporal Retina (Nasal Field)

Blin

d Spo

t

RodsCones


34

Visual angle (minutes of arc)

Visual angle

Targets

Visual angles

.001 .01 0.1 1 10 100 1000 10000

.005

.01

.05

.1

.5

1.0

5.0

10

Minimum separable acuity

Vernier acuity

Stereoscopic acuity

Minimum perceptible acuity

Background Luminance - mL

Targ

et V

isua

l Ang

le -

min

utes


35

.00001 .0001 .001 .01 .1

.001

.01

.1

1 102 1000100

1000

10000

100

5

1

10

25

7.0 6.8 6.4 5.8 5.1 4.4 3.6 2.6 2.1


Thre

shol

d Con

tras

t -

B/B

Pupil Diameter - mm

Luminance contrast is a measure of how much target luminance (Bt) differs from background luminance (Bb). The equation for obtaining contrast is:

CB = or CB X 100 = 50 CBBt - Bb

Bh

121 55.2

10.2 9.65

3.60

340

0.595 - Target Size in minutes of arc


36

1000

100

10.0

1.0

00

0.5 .00 .010 .005 .000

100

10

1

0.1

.01

.00001 .0001 .010 .01 .1 1 10 100 1000

Targ

et S

ize

- m

inut

es


.10

- Target contrast


37

Numbers on curves indicate brightness of pre-exposure white light.

.1

.01

.001

.0001

.000010 10 20 30

Lum

inan

ce T

hres

hold

- m

L

Time in Darkness - min

4 ml

44 ml

447 ml4700 ml


38

0 5 10 15 20

.0001

.00001

Time in Darkness - min

Lum

inan

ce T

hrea

shol

d -

mL

Violet White YellowRed

Pre-exposure brightness of 1.1 - mL Light of the following Colors,


39

0.001 0.01 .1 1 10 100 1000

0

10

20

30

40

50

60

Flic

ker

Freq

uenc

y %

Luminance of Target - mL

Perceived as Steady

Perceived as Flickering


40

0

4

8

12

16

20

20 40 60 80 100 210 140

Angular velocity - deg/sec

Critic

al d

etai

l - M

in o

f ar

c

.04 ft.c

.20 ft.c

1.0 ft.c

2.0 ft.c 25.0 ft.c

125.0 ft.c


MIT OpenCourseWarehttp://ocw.mit.edu

16.400 / 16.453 Human Factors EngineeringFall 2011

For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.

http://ocw.mit.edu

http://ocw.mit.edu/terms

16.400/453j human factors engineering - … factors evaluation 16.400/453 • each student is to...

Documents