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USS McCain collision ultimately caused by UI confusion

arstechnica.co.uk

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Re: USS McCain collision ultimately caused by UI confusion

#231

Post by foldr »

dredmorbius wrote: post #229
foldr wrote: post #217

Earlier quoted context omitted.

I think it's wrong. If you think I am some kind of shill (?), then I guess it makes sense that you would be some kind of conspiracy theorist, given your unwarranted skepticism about the conclusions of the official report.

I made no such accusation. There is considerable informed and expert opinion voiced that the conflicting inputs were a potential issue. A fair bit of that discussed here. There are other instances of conflicted inputs. And despite considering numerous elements of confusion, uncertainty, and information overload, the BEA report doesn't even consider the matter . This calls into question the report itself, the investig…

You insinuated that I had some kind of ulterior motive, in the same way that you are now insinuating that the accident report was a cover up.

As for expert opinion, could you give references? All I can find are articles in the popular press where a journalist emailed someone in the know to confirm that yes, indeed, Airbus control columns are not linked -- which is not a point in dispute.

There's a really simple explanation for why the accident report doesn't consider the issue of the control sticks not being linked. It just wasn't a significant factor in the accident, as far as anyone can tell.

If you have evidence of a cover up, you should provide it. The fact that the report did not draw the same conclusions that you would have drawn is not evidence of a cover up.

Re: USS McCain collision ultimately caused by UI confusion

#232

Post by cmdkeen »

diggernet wrote: post #164
Bromskloss wrote: post #159

Earlier quoted context omitted.

What about the question regarding having one guy doing direction, and another guy doing speed? Is that called for?

Absolutely. Maintaining a ship's heading is a full time job. If you get distracted, you get off course pretty quickly. Speed isn't even really handled on the bridge. The engine order (ahead full, back half, emergency stop, etc) goes to the engine room where multiple people do the work. Note: This is in the context of oil and nuclear steam-powered ships. Gas turbine ships may well have an actual throttle on the bridge…

It may be on a US Navy warship, that absolutely isn't the case for other blue water navies. If anything I would suggest that having too many people involved adds confusion. The OOW has repeaters of the course and speed so that they can verify their orders are being followed, they are the check.

The Wolf Rock collision board of inquiry makes for interesting (and embarrassing) reading around what happens when assumptions are being made about who is doing what.

Re: USS McCain collision ultimately caused by UI confusion

#233

Post by Supernaut »

lucaspiller wrote: post #162
blknmild wrote: post #117

Earlier quoted context omitted.

I'm sure there's a good reason for the "tradition". Similar to a group of monastic monks following some bizarre ritual which could be done in a more efficient way. Someone from westpoint or the naval academy probably knows..

I’d say it’s the same reason why manual transmission vehicles are still more popular than automatic transmission in some countries. Automatic transmission of modern cars is easier (you can give more attention to the road than having to think about changing gears), gives a smoother ride, is more fuel efficient and causes less wear and tear on the engine. It’s a habit that the organisation is used to, so there is resis…

I drive a manual transmission car every day and I'm bemused by your reference to "having to think about changing gears". For an experienced and competent driver, registering and acting upon the need to move up or down a gear usually requires no conscious thought whatsoever. The mechanical process itself literally takes a split second. By contrast, in my one experience with an automatic transmission, it proved to be a constant distraction from the business of steering the car and enjoying the drive. That was because it was never in what I considered the appropriate gear, refusing to change up in a proportionate manner as I accelerated, or to change down quickly enough on upward inclines. It was teeth-grindingly irritating. Admittedly, that was 10 or 11 years ago, and perhaps the state of the art has improved since then.

Re: USS McCain collision ultimately caused by UI confusion

#234

Post by [deleted] »

misnome wrote: post #220
toomanybeersies wrote: post #128

Earlier quoted context omitted.

On a nuclear powered ship, yes, since you still essentially have a steam engine, the engine telegraph (throttle) isn't actually linked directly to the engine. On a modern diesel or gas turbine ship, no there's not. Obviously there are limits to what the engine can do still.

The nuclear part isn’t just used to generate electricity for the motors?

[deleted]

Re: USS McCain collision ultimately caused by UI confusion

#235

Post by dredmorbius »

foldr wrote: post #222
dredmorbius wrote: post #171

Earlier quoted context omitted.

First, I did not say the side-sticks are the fully responsible factor for the accident, but a contributing factor . Second (and as noted in the parallel subthread), the BEA report does not include cockpit transcripts in section 2, 2.1, and relevant subsections, in describing the cockpit situation. It mentions specific utterances of the crew, but not in the specific context and sequence they occurred. Other reports do…

I've addressed the popular mechanics article in other comments. It's difficult to square some of its key claims with the description of events in the accident report. In particular, the report gives no indication that any of the three pilots successfully identified that the plane was stalled. The fundamental issue here is that if only one pilot has his hand on the stick (which should always be true) then linked stick…

Pilot error based on the actions of a single pilot, or even, in extreme cases, two pilots, might reasonably be attributed.

To have three pilots fail to grasp a situation central to principles of flight, and to have similar situations arise in other aircraft, suggests exogenous factors at play.

You've repeatedly made the case that multiple pilots fighting for control indicates a breakdown of cockpit discipline. You've failed to note that the pilots showed no awareness of such a conflict, or, further, that the stick-back position couldn't be readily identified by anyone other than the pilot applying that input.

You're insinuating that AF had three other-than-half-competent pilots in the cockpit, which raises numerous other concerns.

You're litigating use of the term "position" rather than the general understanding of "force feedback" which applies whether controls have a significant range of motion (traditional mechanical yoke) or a very short throw (sidestick).

In general, you're showing very little charitability to points of view differing from your own, which raises concerns.

Re: USS McCain collision ultimately caused by UI confusion

#236

Post by dredmorbius »

foldr wrote: post #231
dredmorbius wrote: post #229

Earlier quoted context omitted.

I made no such accusation. There is considerable informed and expert opinion voiced that the conflicting inputs were a potential issue. A fair bit of that discussed here. There are other instances of conflicted inputs. And despite considering numerous elements of confusion, uncertainty, and information overload, the BEA report doesn't even consider the matter . This calls into question the report itself, the investig…

You insinuated that I had some kind of ulterior motive, in the same way that you are now insinuating that the accident report was a cover up. As for expert opinion, could you give references? All I can find are articles in the popular press where a journalist emailed someone in the know to confirm that yes, indeed, Airbus control columns are not linked -- which is not a point in dispute. There's a really simple expla…

I've asked you to state your interests.

You've declined to do so.

Re: USS McCain collision ultimately caused by UI confusion

#237

Post by PuffinBlue »

mjevans wrote: post #198
FabHK wrote: post #191

Earlier quoted context omitted.

The problem is that you can't "fix" humans. They'll make mistakes. Aviation is as safe as it is precisely because it moved past the "pilot error! that guy just made a mistake, how can one be so stupid" attitude evinced in your comment. You have to look at the entire accident chain, and at the entire system, including training, supervision, redundancy, and, indeed, UX.

Good UI makes the effort of doing the 'right thing' very little, and the effort of doing the 'bad thing' as costly as possible. Design (in my opinion) is planning out what good and bad things are for a given tool and determining how to express that through the UI.

> Design (in my opinion) is planning out what good and bad things are for a given tool and determining how to express that through the UI.

I disagree with the premise you have that the designer deciding what is good and bad is the whole or even the right story. I think I might agree with the implication that a system should make doing cognitively difficult/safety critical things easy but there is no possible way to plan for all eventualities, that's why we have 'intelligent' controllers in ultimate charge.

One day we might have artificial intelligence in charge but we're not there yet.

So instead of the goal of good UX being the designer planning out what is good and bad, it is much better to design a system that reduces cognitive load but presents information about the current state of the system in the most obvious and intuitive way possible. It should do everything it can to make sure the operator understands the current state of the system.

In terms of operating complex physical systems like ships and aircraft the ultimate goal of designing control systems is to simultaneously take as much of the burden off the operator as possible but present all information needed in order to bring the system back to an _understood_ state as rapidly as possible following deviation from that state. This is the only way to maintain _control_.

It's reasonable to try and make it difficult to get to a state that is 'uncontrolled'. But it's imperative that more credence is given to getting a system back to an understood state once the controller finds them self in one that's not understood. It may get to this state in a way the designer didn't plan for, so getting out of it has to be incredibly quick and easy.

Personally, I put more stock in getting the system in an understood state than a controlled one as from there it's easier to return to control. Without understanding the state of the system it's easy to make further mistakes.

Re: USS McCain collision ultimately caused by UI confusion

#238

Post by blattimwind »

NickNameNick wrote: post #168
lucaspiller wrote: post #162

Earlier quoted context omitted.

I’d say it’s the same reason why manual transmission vehicles are still more popular than automatic transmission in some countries. Automatic transmission of modern cars is easier (you can give more attention to the road than having to think about changing gears), gives a smoother ride, is more fuel efficient and causes less wear and tear on the engine. It’s a habit that the organisation is used to, so there is resis…

Automatics are usually less efficient than manuals - the Hydraulic torque converter has to slip to function. That said, the automatic might beat a manual in other metrics.

A modern dual-clutch automatic* switches gears so swiftly and seamlessly that there is no feeling of clutching going on at all, if not for the motor tune or the RPM indicator you wouldn't know it's changing gears. If you disregard either it almost feels as-if the car is going from 0 to 180 in one gear.

* i.e. it doesn't have a torque converter, since it basically has two separate gear sets with two separate clutches. To switch gears it seamlessly moves between gear sets via the clutches. There is no interruption in power.

Re: USS McCain collision ultimately caused by UI confusion

#239

Post by IshKebab »

lisper wrote: post #106

It's not just boats that have safety-critical UI design problems. The avionics in airplanes are becoming so complicated that managing the avionics is almost more difficult than flying the plane. I'm a private pilot who has been flying a Cirrus SR22 for twelve years. In that time it has gone through two major glass cockpit avionics revisions. In the first revision, called the Avidyne, the autopilot was either on or of…

Wow that UI is truly terrible. It's like they said "we need all this information on the screen" and then just dumped it anywhere. Who knew Microsoft Flight Simulator 2.0 was so accurate?

Re: USS McCain collision ultimately caused by UI confusion

#240

Post by blattimwind »

JshWright wrote: post #42
csours wrote: post #24

Earlier quoted context omitted.

The path to a disaster has been compared to a tunnel [0]. You can escape from the tunnel at many points, but you may not realize it. Trying to find the 'real cause' is a fool's errand, because there are many places and ways to avoid the outcome. I do take your meaning, reducing speed and following well established rules would have almost certainly have saved them. 0. PDF: http://www.leonardo-in-flight.nl/PDF/FieldGui…

I've never heard the tunnel analogy. Seems odd, since tunnels generally only have one entrance and one exit... In a lot of fields where the stakes are high and mistakes are costly (aviation and emergency services are the two I'm most familiar with) the analogy used is a chain. Break any link in the chain and you prevent the event. https://www.aopa.org/asf/publications/inst_reports2.cfm?arti...

> I've never heard the tunnel analogy. Seems odd, since tunnels generally only have one entrance and one exit...

Road and train tunnels have many emergency exits...

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