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

Re: USS McCain collision ultimately caused by UI confusion

#261

Post by Piskvorrr » Fri, Nov 03, 2017, 12:10 PM UTC

Supernaut wrote: post #233

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…

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…

Certainly it has. Having converted to automatic transmission recently, shifting is one less thing to keep in the back of your mind (even if it was second nature to me, after many years of driving stick). With the kickdown button, you don't even have to worry about getting enough power in emergency situations ("have I downshifted low enough?").

Even so, the stick driving reflexes only get dulled temporarily - within five minutes of driving stick, you're back up to speed again (pardon the pun).

Re: USS McCain collision ultimately caused by UI confusion

#262

Post by Piskvorrr » Fri, Nov 03, 2017, 12:22 PM UTC

bitwize wrote: post #257

foobarian wrote: post #129

Earlier quoted context omitted.

Don't get me started about TVs. When I grew up our family TV turned on in seconds, and pressing channel up/down reacted in tens of milliseconds.

Y'know how they say "don't touch that dial"? When I grew up, TVs actually still had dials you had to turn. The tuner responded instantaneously when you changed the channel. Now get off my lawn you damn kids.

Of course it did, you were directly manipulating the a resistor in its circuit. Getting the channel just right...and keeping it there...that was, of course, the flipside.

Re: USS McCain collision ultimately caused by UI confusion

#263

Post by lallysingh » Fri, Nov 03, 2017, 12:22 PM UTC

jabl wrote: post #207

diggernet wrote: post #164

Earlier quoted context omitted.

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…

As an outsider (well, I have plenty of experience with pleasure boats/yachts, but none with large ships) it seems really extraordinary that just maintaining a heading would be a full time job. Somehow in airplanes a single pilot manages to control not only the rudder, but throttles, ailerons, elevators, flaps and whatnot while also yakking on the radio. And airplanes zip along at 500 knots rather than 20 like a ship.

And in 3 dimensions (which a sub does too, but not a ship)

Re: USS McCain collision ultimately caused by UI confusion

#264

Post by cocoablazing » Fri, Nov 03, 2017, 12:25 PM UTC

tlb wrote: post #77

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…

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…

Yes, steam demand controls the power response of a nuclear reactor.

Re: USS McCain collision ultimately caused by UI confusion

#265

Post by Piskvorrr » Fri, Nov 03, 2017, 12:25 PM UTC

Cyph0n wrote: post #139

foobarian wrote: post #129

Earlier quoted context omitted.

Don't get me started about TVs. When I grew up our family TV turned on in seconds, and pressing channel up/down reacted in tens of milliseconds.

To be fair, you weren't getting near-instantaneous full HD quality broadcasting with DVR support on your TV back then.

Fair enough, but you were getting useful fallback, the image quality progressively degrading, and even with almost no image, the audio was still intelligible. With digital boradcast, it's all-or-nothing: all is fine, all is fine, until the error correction can no longer save you...and you get soundless picture, with block artifacts. Very useful for emergency broadcasts, when anything unicast will be overloaded as well.

Re: USS McCain collision ultimately caused by UI confusion

#266

Post by avar » Fri, Nov 03, 2017, 12:28 PM UTC

pbhjpbhj wrote: post #251

Marazan wrote: post #225

Earlier quoted context omitted.

The nuclear power plant is heating water to generate steam.

Which presumably drives a turbine to make electric which can run motors, charge batteries, run scrubbers, run heaters, etc., presumably. They're not direct driving the screw with steam power from the reactor heat-exchange, surely.

It's hard to find anything like a schematic of a Nimitz-class carrier for obvious reasons, but as far as I can tell yes, it's all directly steam powered. The reactor boils (sea)water, which is used to power 4 steam turbines[1][2][3], those turbines drive the propellers.

You've probably seen aircraft carrier decks covered in smoke. This is because the Nimitz's catapult system is directly steam powered, service steam is widely used on the class. I can't find a citation for this now (this is from memory) but I saw some documentary on it once where it was mentioned in passing that even the washing machines on the ship were steam powered. There's service steam everywhere on the Nimitz.

Having steam power everywhere introduces a lot of complexities, which is why the Navy's moving away from it with their new carrier class[4]. The Gerald R. Ford-class does away with service steam in favor of more powerful electric generators. There'll be no service steam, just steam to drive the electric turbines.

1. http://www.nimitz.navy.mil/FACTS.html

2. https://en.wikipedia.org/wiki/Nimitz-class_aircraft_carrier#...

3. https://www.marinelink.com/news/dresserrand-propulsion302604

4. https://en.wikipedia.org/wiki/Gerald_R._Ford-class_aircraft_...

Re: USS McCain collision ultimately caused by UI confusion

#267

Post by Piskvorrr » Fri, Nov 03, 2017, 12:31 PM UTC

FabHK wrote: post #189

rangibaby wrote: post #112

Earlier quoted context omitted.

Is there a purpose to the display being so colorful? If AP were the only green thing and the others were monochrome it would stand out more.

While the "AP" indicator is very important, such that overlooking it, or rather missing its absence, could lead to loss of control and death, the same holds for many other of the items displayed.

That's actually a great point: "missing an absence" is far harder than "noting a presence of opposite indicator".

Re: USS McCain collision ultimately caused by UI confusion

#268

Post by no_flags » Fri, Nov 03, 2017, 12:37 PM UTC

gambiting wrote: post #215

NickNameNick wrote: post #168

Earlier quoted context omitted.

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.

Torque converts are the niche choice nowadays, a lot of modern cars have dual-clutch transmissions which are always more efficient than manuals. They use less fuel, shift quicker and commonly have more gears for less strain and better efficiency(almost all new MB cars ship with 9-gear dual clutch tranmissions nowadays for example). But yes, after owning manuals for years I would never go back, an automatic allows you…

I had the reverse experience of you, that is, I always drove automatics and then learned to drive manual later on. I actually felt I was more focused on the road in the manual because I needed to plan ahead for gear shifts. In an automatic everything is taken care of so it's easier for the mind to wander. I thought I was a better driver in the manual. I guess if I drove a manual for years it would probably go on mental autopilot more.

At the end of the day I think manuals are great fun but automatics are more practical. An automatic will never stall out in a safety critical moment, as I always worried I would do in the manual. I've also pondered that if I was ever to sustain a serious injury to an arm or leg, I would probably be able to drive an automatic in an emergency. Driving stick with a broken arm would be substantially more difficult. The fuel economy advantages enjoyed by manuals seem to have dissipated at this point as well.

Re: USS McCain collision ultimately caused by UI confusion

#269

Post by jessaustin » Fri, Nov 03, 2017, 12:44 PM UTC

tormeh wrote: post #72

rdl wrote: post #63

Everyone in the chain of command in 7th fleet (from ADM Smith on down through the captains and those standing watch) should have been separated and potentially prosecuted for negligence. UI confusion would be an excuse for an untrained civilian being put on the bridge and told to run the ship, but not for professionals, and obviously many systems failed for this to happen. When the military runs well, it runs on acco…

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!

Re: USS McCain collision ultimately caused by UI confusion

#270

Post by foldr » Fri, Nov 03, 2017, 12:45 PM UTC

avar wrote: post #258

foldr wrote: post #230

Earlier quoted context omitted.

Every Airbus crash gives rise to lots of FUD in the media. Initially, everyone was blaming AF447 on the vertical stabilizer breaking off ( http://www.businessinsider.com/henry-blodget-air-france-447-... ). I guess they thought they had "enough" data then, and of course plenty of "experts" were on hand to lend credence to this particular speculation. But anyway, the accident report says what it says. I see no reason t…

Equating initial media speculation not even 3 weeks from the crash when the black box was still at the bottom of the ocean with analysis done after all the data was in by industry experts in flight safety is absurd.

My point regarding the Business Insider article is that lots of pilots and other 'experts' were willing to give quotes to journalists back then, even though they knew nothing really about what had happened. Captain Sullenberger was hired by CBS as an aviation safety expert in 2011. He's expressing an opinion about the sidesticks that many other professional pilots disagree with (see e.g. the endless forum discussions on pprune). You can find pilots who support all kinds of wacky theories of various accidents. Sullenberger has a high profile (deservedly), and can get on TV.

The fundamental issues with Sullenberger's claim that the accident would be much less likely in an aircraft with conventional controls are (i) that there have been multiple crashes in such aircraft caused by unrecovered recoverable stalls (e.g. Colgan 3407, Turkish 1951) and (ii) that there is pretty good evidence from the transcript that the PNF was aware of the PFs inputs in any case. This forum post has a good summary:

http://www.airliners.net/forum/viewtopic.php?t=772033&start=...