Engineering a Safer World

For those of you interested in such things here’s a link to a draft copy of Professor Nancy Leveson’s latest book on system safety Engineering a Safer World, and her STAMP methodology. Like Safeware it looks to become another classic of the system safety canon.

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Writing Specs for Fun and Profit

Here’s a draft of my latest paper to be presented at the Congress of Rail Engineering (CORE 2012) this year in Brisbane. This is more of a mainstream systems engineering paper on the mechanics of writing specifications and some of the conceptual problems in doing so.

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24 Hours at Fukushima

In an article published in the online magazine Spectrum Eliza Strickland has charted the first 24 hours at Fukushima. A sobering description of the difficulty of the task facing the operators in the wake of the tsunami. Her article identified a number of specific lessons about nuclear plant design, so in this post I thought [...]

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On Possibilistic Design and Aviation Safety

I’ve recently been reading John Downer on what he terms the Myth of Mechanical Objectivity. To summarise John’s argument he points out that once the risk of an extreme event has been ‘formally’ assessed as being so low as to be acceptable it becomes very hard for society and it’s institutions to justify preparing for it.

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When All You Have is a Hammer…

Why We Automate Failure A recent post on the interface issues surrounding the use of side-stick controllers in current generation passenger aircraft led me to think more generally about the the current pre-eminence of software driven visual displays and why we persist in their use even though there may be a mismatch between what they [...]

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Pilots in the Loop? Airbus and the FBW Side Stick

Airbuses side stick improves crew comfort and control, but is there a hidden cost? The Airbus FBW side stick flight control has vastly improved the comfort of aircrew flying the Airbus fleet, much as the original Airbus designers predicted (Corps, 188). But the implementation also expresses the Airbus approach to flight control laws and that [...]

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Side Sticks and Shared Situational Awareness

One of the less often considered aspects of situational awareness in the cockpit is the element of knowing what the ‘guy in the other seat is doing’. This is a particularly important part of cockpit error management because without a shared understanding of what someone is doing it’s supremely difficult to detect errors. The replacement of the central control stick with side stick ‘glass’ controllers eliminates a little acknowledged means of coordinating a common understanding of control inputs between aircrew with the potential for a hazardous loss of crew error management.

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On the Brittleness of Software

Reading through the BEA’s precis of the data contained on AF447′s Flight Data Recorder you find that during the final minutes of AF447 the aircrafts stall warning ceased, even though the aircraft was still stalled. This loss of stall warning removed a significant cue to the aircrew that they had flown the aircraft into a deep stall, undoubtedly adding to their confusion. SU4CF4KDVSWQ

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While We’re on the Subject of Human Factors

One of the areas of human factors in design is the physical layout of a seated workstation or control console to suit the functional reach capabilities of the user population. Should be simple right? Wrong.

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Through a Mirror Darkly…

Good and bad in the design of an Oliver Hazard Perry class frigates ECS propulsion control console HMI.

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QF 32 and Checklists

According to the preliminary ATSB report the crew of QF32 took approximately 50 minutes to process all the Electronic Centralised Aircraft Monitor (ECAM) messages. So, two questions for the ATSB. First would the normal three man crew have been able to handle the ECAM checklist work as readily? Second should the checklist processing have taken 50 minutes which is a very, very, long time in a mid air emergency?

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Managing the Emergent Properties of Design

Back in 1999 I co-authored this paper with Darren Burrowes a colleague of mine on the ADI Minehunter project to capture some of what we’d learned about emergent design attributes and their management on that project. Darren got to present the paper at INCOSE’s International Symposium in Brighton England 1999.

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Soviet Buran Shuttle was Safer than American Shuttle

Soviet Shuttle was safer by design According to veteran russian cosmonaut Oleg Kotov, quoted in a New Scientist article the soviet Buran shuttle (1) was much safer than the American shuttle due to fundamental design decisions. Kotov’s comments once again underline the importance to safety of architectural decisions in the early phases of a design.

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Pitch Ladders and Unusal Attitude Recovery

Because they have typically pitch unity ratios (1:1) scales, aircraft primary flight displays provide a pitch display that is limited by the vertical field of view. This display can move very rapidly and be difficult to use in unusual attitude recoveries becoming another adverse performance shaping factor for aircrew in such a scenario. Trials by the USAF have conclusively demonstrated that an articulated style of pitch ladder can reduce disorientation of aircrew in such situations.

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Risk, Puzzles and Mystery

I recently re-read the article Risks and Riddles by Gregory Treverton on the difference between a puzzle and a mystery. Treverton’s thesis, is that there is a significant difference between puzzles, in which the answer hinges on a known missing piece, and mysteries in which the answer is contingent upon unknowables. So is safety a puzzle or a mystery?

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The Altair Lander High Gate

I’m currently reading a report prepared by MIT’s Human and Automation Labs on a conceptual design for a lunar lander human machine interface. As all really interesting papers do it raises as many questions as it answers.

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Making it HOT for the Operator

Recent work in complexity and robustness theory for engineered systems has highlighted that the architecture with which these systems are designed inherently leads to ‘robust yet fragile’ behavior. This vulnerability has strong implications for the human operator when he or she is expected to intervene in response to the failure of system.

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The Right Attitude

How the design of the Apollo Command Module Attitude Reference Indicator illustrates the importance of cultural cliches or precedents in coordinating human and software behaviour.

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UAV and COMAIR Near Miss … Somewhere over Kabul

A UAV and COMAIR near miss over Kabul illustrates the problem of emergent hazards when we integrate systems.

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An Architectural Lesson From Apollo 13

A near disaster in space 40 years ago serves as a salutory lesson on common cause failure.

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