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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

#51

Post by foldr »

dredmorbius wrote: post #48
foldr wrote: post #13

Earlier quoted context omitted.

If you're going to go against the conclusions of the accident report, which is very thorough, you'll have to do more than just assert that the side sticks were responsible. Check it out here: https://www.bea.aero/docspa/2009/f-cp090601.en/pdf/f-cp09060...

I have read it. Several times.

Great, the pages and sections are numbered, so it's easy to refer to the parts of it that support your theory. Or alternatively, you can direct us to whatever conflicting sources of information you believe are more reliable than the official accident report.

Re: USS McCain collision ultimately caused by UI confusion

#52

Post by inferiorhuman »

JshWright wrote: post #46
tlb wrote: post #3

Amazing that someone would design in multiple steering wheels, only one of which is active, and no big indicator to make it super-obvious which one it is. Also amazing that there's a mode where moving a control sometimes controls all engines, sometimes just one.

Decent odds you've flown on an airplane with a similar UX for primary flight controls. Airbus uses two "side stick" controllers that are on opposite sides of the cockpit. This was a contributing factor in the Air France 447 crash.

> > Amazing that someone would design in multiple steering wheels, only one of which is active, and no big indicator to make it super-obvious which one it is.

> Decent odds you've flown on an airplane with a similar UX for primary flight controls.

Ah, well Airbus does a few things. 1.) A "dual input" warning is issued if there is an attempt at using both controls simultaneously. 2.) There are lights to indicate when your sidestick is active and when it is not.

Re: USS McCain collision ultimately caused by UI confusion

#53

Post by inferiorhuman »

NoPiece wrote: post #11
foldr wrote: post #6

Earlier quoted context omitted.

>So, basically this was a reprise of the AF 447 crash at sea, where lack of clear command authority combined with a maddeningly poorly-thought-out UI resulted in a serious accident with loss of life. I don't want to take this off on a tangent, but this theory of the AF 447 crash keeps getting repeated online despite the fact that the accident report did not conclude that the UI was a factor. If it's got to the point…

I'd call it an interpretation, not a theory. But clearly the conflicting inputs was a UI problem, and while there may be tradeoffs, a better UI could have prevented the AF 447 crash.

Basic airmanship could've prevented the crash too. The pilot-in-command got a stall warning and pulled back on the stick, climbing to 38,000 feet.

That's not a UI issue, it's a forgetting one of the most fundamental rules of flying issue.

https://aviation.stackexchange.com/questions/1418/what-happe...

Re: USS McCain collision ultimately caused by UI confusion

#54

Post by zaroth »

Jtsummers wrote: post #41
monocasa wrote: post #38

Earlier quoted context omitted.

Because he used block quote syntax. It's designed for code on HN's implementation, so it preserves newlines, instead making you scroll. It's a poor choice for quoting non computer languages.

More importantly, in mobile the code block's width is only 200 pixels.

Seriously this. Not wrapping text doesn't also mean fixed width 200px viewport.

The problem isn't "because they used codeblock" the problem is codeblock is broken.

Re: USS McCain collision ultimately caused by UI confusion

#55

Post by mikeash »

foldr wrote: post #36
mikeash wrote: post #31

Earlier quoted context omitted.

This transcript: http://www.popularmechanics.com/flight/a3115/what-really-hap... I’m not talking about the captain, I’m talking about the other pilot at the controls, Robert. He also held the stick back for some time, but he appears to have done this in the mistaken belief that the correct recovery procedure had been tried and failed.

That is an article in popular mechanics that contains a few excerpts from the transcript selected in order to make a particular point. The accident report gives a detailed description of the behavior of both pilots before the copilot entered (2.1.2.3). One possible misconception here is that the copilot would have had his hands on the stick. It isn't normal for both pilots to have their hands on the stick. Only the p…

I believe this is the official transcript: https://www.bea.aero/uploads/tx_elyextendttnews/annexe.01_04...

I see that the first link I posted doesn't contain everything, but I don't see any major omissions either.

At 2:11:37.5, Robert takes control of the plane. According to the report, he pushed the stick to the left twice. Bonin then took back control. Figure 69 on page 96 of the report you linked shows Bonin's pitch inputs during this period. He applies near maximum nose-up pitch right as Robert takes control, and keeps it there. Robert would have felt this had the controls been connected, since he was attempting to control the plane at that time. The report says that Bonin quickly took back control, but the transcript indicates no communication regarding this, which makes it likely they were both attempting to control it for at least a brief period. That figure also indicates that at no time was Bonin's stick ever neutral, so it seems that he never stopped trying to fly the plane even when Robert was nominally in control. Without physical feedback, neither one seems to have realized this. No wonder they were confused about what was going on!

Re: USS McCain collision ultimately caused by UI confusion

#56

Post by mustacheemperor »

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 think the idea is that if you are stuck in a dark train tunnel and there's a train coming towards you, there may be doorways, recesses, etc in the walls that are invisible without the proper tools (flashlight, etc).

Re: USS McCain collision ultimately caused by UI confusion

#57

Post by tantalor »

csours wrote: post #47
JshWright wrote: post #42

Earlier quoted context omitted.

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...

It's the perception tunnel. There are many branches, but only one route is followed. In hindsight, you can see all the branches and call out everything that went wrong.

Normally that is called "tunnel vision".

https://en.wiktionary.org/wiki/tunnel_vision

(figuratively) The tendency to focus one's attention on one specific idea or viewpoint, to the exclusion of everything else; a one-track mind.

Re: USS McCain collision ultimately caused by UI confusion

#58

Post by mschuster91 »

tlb wrote: post #3

Amazing that someone would design in multiple steering wheels, only one of which is active, and no big indicator to make it super-obvious which one it is. Also amazing that there's a mode where moving a control sometimes controls all engines, sometimes just one.

> Also amazing that there's a mode where moving a control sometimes controls all engines, sometimes just one.

This is a fallback in case the primary rudder fails. You can still shift left or right, but you will take more time and it will be far less precise than using the rudder.

This is also valid for aircraft, where not only the rudder can be compensated but also the elevator (aka up/down) by simultaneously modifying the power of all engines. You can see a list at https://en.wikipedia.org/wiki/Flight_with_disabled_controls.

Re: USS McCain collision ultimately caused by UI confusion

#59

Post by cyberferret »

oasisbob wrote: post #9
tlb wrote: post #3

Amazing that someone would design in multiple steering wheels, only one of which is active, and no big indicator to make it super-obvious which one it is. Also amazing that there's a mode where moving a control sometimes controls all engines, sometimes just one.

Having differential engine control isn't too surprising - it's just another way to maintain a course in addition to the rudder. Jetliners have gangable throttle controls for their engines, albeit with what is probably a much better interface.

Airliners usually have a hardware clip to 'gangload' all throttles together, and the 'interface' of having two or more separate levers next to each other makes it obvious if you missed one while moving them, or notice that the clip is flipped so the levers now work independently instead of all as one.

Then again, in high stress situations even totally obvious signs like this can be missed, as evidenced by the Qantas 747 crew on the famous runway overrun in Thailand some years ago. I believe in that case, a large contributing factor was when the captain went to pull the levers back over the rear detents for reverse thrust after landing on the wet runway, he only grabbed three of the levers, and left one engine running at just over idle speed.

Re: USS McCain collision ultimately caused by UI confusion

#60

Post by throwaway613834 »

wtallis wrote: post #35
drsopp wrote: post #32

Earlier quoted context omitted.

I’m sorry for bringing this up here, but why do I need to scroll sideways in Safari on iphone on Hacker News every time there is a quote written in an unproportional font? Just, why?

Because the markup for those blocks isn't intended for general-purpose quotations; it's blocks. You don't word-wrap code.

Pretty sure merely not wrapping doesn't imply quite as horrible a UI as we have there.
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