USS McCain collision ultimately caused by UI confusion • Hacker News Board

Re: USS McCain collision ultimately caused by UI confusion

#351

Post by josefx » Sat, Nov 04, 2017, 9:04 AM UTC

cocoablazing wrote: post #275

PeterisP wrote: post #210

Earlier quoted context omitted.

You want the person managing the speed to be focused on that if managing speed is still inherently and unavoidably attention-intensive - if modern control technology is able to automagically maintain speed at x knots, adjusting all the various engine control parameters to implement that, then an extra person in the loop only means an extra chance for mistakes or delays.

If the military learned a lesson from exploding a reactor with an automatic control system, you might never know - it's not required to be reported to the public.

If an automatic control system can blow up a reactor so can the manual one. You have a problematic design issue in both cases. You can also still assign someone to keep an eye on the reactor in case things go bad an have that person pull an emergency stop or warn the guy in charge. There is no reason to relay every little speed change through several people.

Re: USS McCain collision ultimately caused by UI confusion

#352

Post by dredmorbius » Sat, Nov 04, 2017, 10:39 AM UTC

gsnedders wrote: post #346

dredmorbius wrote: post #325

Earlier quoted context omitted.

"PIC", pilot in control , refers to the pilot actually flying the plane. Not the command or seniority structure amongst pilots. There were a Captain and two co-pilots aboard AF445. The junior co-pilot was PIC for much of the incident.

PIC is in command , not in control. In plenty of short-haul flights, the FO can be PF, but they aren't competent to be PIC. See also " rel="nofollow">https://aviation.stackexchange.com/questions/33414/who-is-th... . As in the AF447 case, the PIC will delegate to an acting PIC while they are on their rest break, but ultimate responsibility still remains with them.

My error. I was getting confused on the BAE terminology:

PF Pilot Flying

PNF Pilot Not Flying

https://www.bea.aero/docspa/2009/f-cp090601.en/pdf/f-cp09060...

Re: USS McCain collision ultimately caused by UI confusion

#353

Post by polynomial » Sat, Nov 04, 2017, 5:20 PM UTC

Alan Cooper observes in his book Inmates are Running the Asylum than the majority of non-terrorist related airline disasters are caused by bad UI.

Not instrumentation as such, but the modern version of it which is the "interface."

One example he cites is a pilot selecting a destination beacon using a "simple" drop down menu. 2 possible options, similar in name and adjacent on the alphabetized list are deadly in difference. One is the correct orientation, the other takes the plane directly into the side of a mountain.

Given the state of confusion that is modern UI design, this revelation is not too surprising.

Re: USS McCain collision ultimately caused by UI confusion

#354

Post by dreamcompiler » Sat, Nov 04, 2017, 5:54 PM UTC

oasisbob wrote: post #183

dreamcompiler wrote: post #179

Earlier quoted context omitted.

And the way to solve this -- at least for the case of consecutive channel surfing -- is to have multiple decoders and multiple buffers. It's simply precaching.

Eventually you're going to run into RF limits, especially if the signal is coming in over the air. You're sure this is engineering laziness? How much extra would you pay for a TV with faster channel changing?

I'd pay extra for it. I'd pay even more for a TV that didn't spy on me and that couldn't update its firmware without my consent. But I'm probably not the target consumer.

Re: USS McCain collision ultimately caused by UI confusion

#355

Post by dTal » Sat, Nov 04, 2017, 6:09 PM UTC

mschuster91 wrote: post #58

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 modifyi…

The difference being that aircraft throttles are not modal and are always 1 throttle = 1 engine.

Re: USS McCain collision ultimately caused by UI confusion

#356

Post by mikeash » Sat, Nov 04, 2017, 8:12 PM UTC

foldr wrote: post #342

mikeash wrote: post #304

Earlier quoted context omitted.

Whether or not they knew they were fighting is not quite the relevant bit. What's relevant is knowing what the other guy's inputs are. Given that the other two pilots were quite surprised once Bonin finally said that he had been holding the stick back the entire time, they clearly were not aware of this. You say it's not so clear that this ever really happened, but it's pretty clear to me from the official transcript…

But look at what Robert says before the captain enters: "climb climb climb". He still didn't have a clue that the plane was stalled, even though this could easily have been figured out from the absolutely crazy combination of attitude, throttle setting, and rate of descent. It's the captain who's surprised by the stick being held back, not Robert. In fact, earlier portions of the trascript suggest that Robert was kee…

What do you mean, it seems that once everyone was aware of what the PF was doing, a correct recovery procedure was still not initiated? Once they realized what was happening, in the bit of the transcript I quoted, they immediately initiated the correct recovery procedure. It was just much too late by then.

Before that, yes, Robert didn't realize the plane was stalled. But I would bet that this is partially due to having no idea what Bonin's control inputs were. One of the signs of a stall is stick back. If he didn't think the stick was back, he wouldn't think the plane was stalled.

Re: USS McCain collision ultimately caused by UI confusion

#357

Post by azernik » Sat, Nov 04, 2017, 10:49 PM UTC

krschultz wrote: post #290

Animats wrote: post #73

There was a ferry accident involving a similar transfer of control problem in New York harbor.[1] Ferries have a lot of maneuvering modes and directional thrusters, because they do so many dockings, and so they have a more complex control problem. The pilot put the system into a backup dumb mode while in cruise, then changed stations to where he could best see the dock while still in the wrong mode. Rammed the dock a…

Reading the raw accident report, I draw the opposite conclusion. The sequence of events that led to the accident started with one person controlling both steering & throttle. The reason for splitting responsibility is that the original helmsman was overwhelmed by the number of actions required to control both. This reminds me of the Air France crash that was largely due to split control. The UX of transferring contro…

To be fair, split throttles is not a sane or intuitive default.

Re: USS McCain collision ultimately caused by UI confusion

#358

Post by azernik » Sat, Nov 04, 2017, 10:56 PM UTC

jessaustin wrote: post #269

tormeh wrote: post #72

Earlier quoted context omitted.

From what I hear the Navy has been very diligent about accountability. There are problems you can't really hard-ass yourself out of.

Multiple crewman have died from multiple preventable errors in multiple incidents. I haven't heard about any firing squads for COs? Normally we Americans are so enthusiastic about severe penalties? Watch-keeping and safe navigation are boring , so officers need extra incentive to pay attention to them!

"Preventable" doesn't mean "preventable by harsher discipline".

Re: USS McCain collision ultimately caused by UI confusion

#359

Post by jakub_g » Sat, Nov 04, 2017, 11:34 PM UTC

zkms wrote: post #297

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 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. This is incorrect. The BEA report explicitly blames the lack of an AoA display and recommends that an AoA indicator be directly visible to the pilots. The aircraft already has sensors to measure AoA to feed the flight compu…

> The AoA invalidation logic ("mark AoA measurements as invalid if airspeed is less than 60kt") made the stall warning turn off as the stall became even deeper, making diagnosis of the stall more complicated. Worse, the BEA report states that the appropriate (nose down) control input led to the stall warning reactivating (since such an input would increase airspeed above the 60kt threshold -- inherent to a proper stall recovery), leading the pilot flying to reverse their control inputs and return the aircraft into a worse stall

This sounds extremely confusing indeed. Having this kind of inconsistencies under high pressure is something that would need a really experienced and steel-nerve person to handle.

Re: USS McCain collision ultimately caused by UI confusion

#360

Post by gaius » Sun, Nov 05, 2017, 10:58 AM UTC

toomanybeersies wrote: post #128

tlb wrote: post #77

Earlier quoted context omitted.

In the steam days, it was a major operation to adjust the output of an engine. Valve linkages had immediate effect on the output, but you also had to adjust the boiler heat input to keep the temperature within limits. Far enough back, there were men shoveling coal into the boilers who had to be told to slow down or speed up. Do you think it's mainly bureaucratic inertia that keeps it separate? Or is there something m…

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.

On a nuclear powered ship, yes, since you still essentially have a steam engine

Right, this is why when BAe lied to the UK claiming that the QE class carriers could easily be converted to cats'n'traps every engineer in the country said WTF? Because with no nuke where do you get either the steam for the catapults or the surplus electrical power for EMALS when you want to steam directly into the wind for deck operations? But our idiot PPE-educated politicians lapped it up and signed cheques for billions anyway...