Mayday Mark 2

More software lessons from aviation disasters

Transcript

1. Mayday Mark 2! More Software Lessons from Aviation Disasters Adele Carpenter @iam_carpenter
3. Source: PlaneCrashinfo.com
4. Source: PlaneCrashinfo.com
5. Source: PlaneCrashinfo.com
6. Source: PlaneCrashinfo.com
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12. Improvements in Aviation Safety • 1980s • Crew Resource Management after UA173 in 1978 • Trained to use all available resources to improve safety • 1900s and 2000s • CRM rolled out to emerging markets • Fly-by-wire • Better data, warning systems, and training
13. Fly-by-wire • First deployed on the F-16 in 1974 • No mechanical connection between controls and flight surfaces Photo by Chandler Cruttenden on Unsplash • Computer acts as middleman for pilot’s instructions • Computer-interpreted instructions delivered “by wire”
14. Courtesy of wikipedia commons Fly-by-wire • Entered commercial aviation with the Airbus A320 in 1988
15. Approaches to Automation • Airbus • Use safe flight envelope to fullest extent • Normal, Alternate and Direct Law • Pilot can’t choose the law • Computer-centric approach • Boeing • Pilot-centric approach • Mix of fly-by-wire (777,787) and mechanical controls (737)
16. Case Study • AirFrance 447 • Crashed June 1st, 2009
17. Photo by Andrés Dallimonti on Unsplash
18. Photo by Andrés Dallimonti on Unsplash
19. Photo by Andrés Dallimonti on Unsplash I have the controls!
20. Photo by Andrés Dallimonti on Unsplash We haven’t got a good indication on speed Alternate Law, protections low
21. Photo by Andrés Dallimonti on Unsplash OK, OK, I’m going back down Watch your speed, watch your speed! According to all three you’re going up, so go back down
22. Photo by Andrés Dallimonti on Unsplash I’m in TOGA, right? Damn it! Where is he?!
23. Photo by Andrés Dallimonti on Unsplash I don’t have control of the aeroplane anymore now! Controls to the left!
24. Photo by Andrés Dallimonti on Unsplash We’re losing control of the aeroplane What’s happening, I don’t know what’s happening
25. Photo by Andrés Dallimonti on Unsplash …but I have been nose up for a while Climb climb climb climb
26. Photo by Andrés Dallimonti on Unsplash Go ahead, you have the controls, we are still in TOGA, yeah Give the controls to me, give the controls to me!
27. Photo by Andrés Dallimonti on Unsplash We are going to crash, this can’t be true!
28. Photo by Força Aérea Brasileira on Flickr.com
29. https://www.standard.co.uk/news/world/air-france-airbus-cleared-manslaughter-flight-af447-rio-paris-atlantic-crash-b1074618.html
30. Redundancy more is always better?
31. Longest 8 minutes
35. Redundancies in play • Redundancy of data • Static redundancy • Two systems can outvote the other • External redundancy • External system integrates data from multiple sources
36. AirFrance 447 Series of unfortunate events • Loss of reliable airspeed • Autopilot disconnects, Captain absent • Abundance of alerts about consequence rather than origin of the problem • Failed to diagnose the situation and apply appropriate checklist
37. AirFrance 447 Series of unfortunate events • Startle effect, pilot irrationally pushed nose up • No anti-stall protection • Pilots cannot see each other’s controls/inputs • Conflicting inputs cancelled each other out
38. How do we design more human- centric systems in a digital world?
39. Features of Humanity • We have a limited working memory • 5-9 chunks of novel information • 2-4 can be worked on at once • Long term memory items are on top of this Bugs
40. Copa Airlines Flight 201 12df - Copa Airlines Boeing 737-200; HP-1297CMP by Aero Icarus, used under CC BY 2.0 license https://www.flickr.com/photos/aero_icarus/5157052345
41. Copa Airlines Flight 201 Photo via wikimedia commons
42. Gyroscope icons created by Freepik
43. Gyroscope icons created by Freepik
44. ADI: Attitude Director Indicator Photos courtesy of BITS Consultancy Both on (bad) data from Captain’s gyro Give captain auxiliary (good) data
45. Features of Humanity • We have a limited working memory • We have a blind spot for our assumptions Bugs
46. Photo via wikimedia commons
47. Features of Humanity • We have a limited working memory • We have a blind spot for our assumptions • We do irrational things Bugs
48. Photo via Air Accidents Investigation Branch
49. Photo via Her Majesty's Stationery Office
50. Features of Humanity • We have a limited working memory • We have a blind spot for our assumptions • We do irrational things • We get used to things Bugs
51. Photo by Mark Ijsseldijk
52. Photo via wikimedia commons De Havilland Comet 1
53. • Users is a wider definition than you think Take-aways • The human element increases as a technology matures Weigh extra safety against the cognitive load put on users Shift from making technology better to understanding users better Start thinking of yourself as a user of the systems you build • We have significant shortcomings Simply because we are human. Work with it, not against it! But it’s the way we approach these problems that matters • Rapid adoption = problems • More redundancy is not always better
54. Thank you! Adele Carpenter @iam_carpenter