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SFO near miss might have triggered aviation disaster (mercurynews.com)
481 points by milesf on July 11, 2017 | hide | past | web | favorite | 414 comments



Attempts to take off from or land on taxiways are alarmingly common, including those by Harrison Ford:

  Harrison Ford won't face disciplinary action for landing on a taxiway at John Wayne Airport [1]

  Serious incident: Finnair A340 attempts takeoff from Hong Kong taxiway [2]

  HK Airlines 737 tries to take off from taxiway [3]

  Passenger plane lands on the TAXIWAY instead of runway in fourth incident of its kind at Seattle airport [4]

[1] http://www.latimes.com/local/lanow/la-me-ln-ford-taxiway-agr...

[2] https://news.aviation-safety.net/2010/12/03/serious-incident...

[3] https://www.flightglobal.com/news/articles/hk-airlines-tries...

[4] http://www.dailymail.co.uk/travel/travel_news/article-337864...


There was a Delta incident at KATL where a plane landed on a taxiway.

NTSB report: https://www.ntsb.gov/about/employment/_layouts/ntsb.aviation...

Here is a comment from the NTSB report: """ Observations made from the flight deck during the flight test approaches indicated that when the lights were set to the same levels as were encountered by the incident crew, from about DEPOT intersection, the runway 27R centerline lights were not identifiable and the taxiway M centerline lights were more prominent. When established on final, the taxiway signs were more visible than runway 27R edge lights. At about 500 feet above ground level the runway centerline lights were barely visible and it appeared that some lights may have been out. The color of the blue taxiway edge lights became distinguishable at about 500 feet above ground level while on approach. """


This is facilitated by the fact that in some airports, taxiways and runways are similar and sometimes even used interchangeably (!), i.e. a runway may be remarked as taxiway and vice versa. So it's not 'how can he be so dumb' moment, in some case you have no way to tell the difference unless you just know.


Yeowch. I was about ready to make a comment about how the airport/approach plates should make something like this impossible, but then I looked up the diagram for SEA:

https://flightaware.com/resources/airport/SEA/APD/AIRPORT+DI...

Basically, you've got a runway, the taxiway of the same length as the runway!, and then two longer runways from left to right. I totally see how someone could make this mistake in bad lighting or weather!


And a note on that diagram:

    CAUTION:
    Pilots are cautioned not to
    mistake Twy T for a landing
    surface.


It feels like it could be solved incredibly easily by a row of lights at the beginning/end of both the taxiway and the runway, bright red for taxiway, bright green for the runway. If you are attempting to land on the strip marked red, then you are doing something wrong. In case that the taxiway is legitimately used for landing, change the colours around.

I guess it hasn't been done for "reasons", I'd be quite interested in hearing why.


This already exists. Runway is lit up in white, has a green strip of lights at the close end as you look at it, and instrument rated fields have a chase strobe that points right to the end of the runway. Taxi ways are blue.


Things like this are being tried. SeaTac airport has a taxiway which is large, parallel, and frequently (enough) mistaken for a runway.

> SEA-TAC personnel have been very proactive in trying to reduce the problem, including the installation of an unlit, nonreflective elevated lighted X at the threshold of taxiway Tango; broadcasting a notice on the Automatic Terminal Information Service (ATIS) not to mistake the parallel taxiway for the adjacent runway; posting warnings on aeronautical charts not to mistake the taxiway for runway 16R; and the development of numerous training aids and brochures that explain the problem to transient pilots traveling through SEA-TAC.

(Testing of multiple methods begins on page 5)

http://www.airtech.tc.faa.gov/safety/downloads/TN07-54.pdf


"...including the installation of an unlit, nonreflective elevated lighted X at the threshold of taxiway Tango..."

Unlit lighted X. Right.


My assumption based on nothing in particular is that one (of unlit/lighted) means 'Lights contained within the X illuminating it from within' and the other means 'Lights external to the X illuminating it from without'


It is done pretty much like that. PDF warning, page 31: https://www.faa.gov/airports/southern/airport_safety/part139...

Taxiways are marked with blue lights.

Here's a video of a night landing on the same runway, the approach lighting is unmistakable: https://www.youtube.com/watch?v=rNMtMYUGjnQ


Yeah. At 1:18 that's clearly HIRL enabled. There's no ambiguity that's for a runway rather than taxiway. And it's not possible to visually misalign yourself with the taxiway, the whole point of HIRL is a visual aid for precision instrument landings in bad weather for Cat I and II ILS landings. On an instrument landing, it's not legal to go below decision height (200 and 100 feet respectively) unless you meet the visual reference requirement in 91.175 c3, ergo the HIRL lighting is simply unambiguous for a night VFR landing, and makes me wonder if it was even on.


this sounds like the start of a good idea, but we should choose something that works for colorblind people and red/green colorblind people too.


Stupid question - can you be certified as a commercial pilot if you are colourblind?


No, you can't. A friend of mine couldn't become a commercial pilot because he has some kind of colourblindness.

However, I remember him trying for some time and even campaigning for colourblind people to be admissible as commercial pilots because for the actual flying colourblindness doesn't seem to matter.

So, perhaps ridiculous as it may sound taking colourblindness into account when proposing such an improvement isn't such a weird idea after all.


You can become color blind later though.


Commercial pilots are generally required to take a regular medical (it's every 6 months or 12 months in the UK).

If a pilot were to acquire colour blindness, they'd be obliged to ground themselves and report the condition to the aviation authority.


Or temporarily from medication, particularly those used to treat erectile dysfunction and benign prostatic hyperplasia [1][2].

[1] https://www.faa.gov/about/office_org/headquarters_offices/av...

[2] https://www.leftseat.com/viagra.htm


... and as a professional pilot, you'd probably have to consult a flight physician if you were taking meds like these.


Actually, airline pilots (and pilots generally) are not the only people you need to take into account here. Many other potential users of the runways and taxiways would need to be taken into account, including ground staff and maintenance staff. Since I doubt that all of these are ruled out on the basis of colourblindness, it makes sense to construct a system that is impervious to ambiguity due to colourblindness.


But ground and maintenance staff don't need to identify them by colour from far away. For them, you could rely on simple signage.


Not a stupid question at all. I clearly remember doing the colour blind test during my preliminary medical when I arrived at flying school to get my commercial licence.

The test consists of going through a book with images made up of different coloured dots, and within each image was a coloured number made up of similar dots. We simply had to flip through the book and identify the number within each image.

I was totally smug as I flipped through the book, calling out the numbers and watching the doctor tick off his chart. But towards the end of the booklet, I reached a page, and the image was just a jumble of dots to me. I couldn't see a number. I remember the panic and tightening in my chest as I thought to myself "Oh No, I can't see the number - I MUST be colour blind!! My dream of being a pilot is OVER".

I stared and stared at the page, but in the end had to concede defeat and I quietly told the doc that I couldn't see the number on that page. "Oh", he replied casually. "That's OK, there isn't one on that page!". And he grabbed the booklet and tossed it back on his desk saying "You passed."


Yes, but the certificate comes with a limitation (color signal landing daytime only proscription; or night and color signal landing proscription).

The requirements vary depending on class of medical certificate but in this context it's a class I medical for airline transport pilots (not commercial pilots) so it's complicated.

Also, full on dichromats or monochromats are rare. Usually people are one of three anomalous trichomats. Hence testing is required to determine if it's a problem. The initial test is designed to have a high failure rate, and the exception tests to get the restrictions lifted take more effort.

https://www.aopa.org/go-fly/medical-resources/health-conditi...


You can’t even be certificated as a Private Pilot if you are colorblind.



Why do people comment on things they know nothing about? Of course you can.


It's HN.... I get a good laugh out of all these aviation related threads. Understandably your average CS undergrad doesn't have much real aeronautical knowledge but that doesn't stop everyone from blowing up the comments every time the word 'airplane' is uttered.


You can, but you're not allowed to fly at night.


No you just get a night flying and color signals proscription on your certificate if you're a monochromat or dichromat (full color blindness); if you merely have a color discrimination problem by being an anomalous trichromat, you might pass the test, or fail it but then get an exemption (reversal of the prior failure) by later passing a more involve series of tests.


My father is red-green colorblind and he flies small planes.


It’s SFO though. And he’s an airline captain, so he should know.


The absolutely stellar safety record of the airline industry exists because they have repeatedly and consistent pushed past human error as an explanation for a crash.

Understanding that if a human made this mistake, another future human will likely make the exact same mistake, they push to understand _why_ an airline captain that should know made this error. Then try to correct for that.

If every crash was written off as "the captain should have known better", aviation would not be nearly as safe as it is.


Someday, perhaps computer programmers will start applying this principle.


Perhaps not all tech companies care to push past human error in each postmortem (or even have a proper formal process at all), but some are known to do just that. Etsy and Google are among the well-documented cases.

> This idea of digging deeper into the circumstance and environment that an engineer found themselves in is called looking for the “Second Story”. In Post-Mortem meetings, we want to find Second Stories to help understand what went wrong.

— Blameless PostMortems and a Just Culture,

https://codeascraft.com/2012/05/22/blameless-postmortems/

> Blameless postmortems are a tenet of SRE culture. … Blameless culture originated in the healthcare and avionics industries where mistakes can be fatal. These industries nurture an environment where every "mistake" is seen as an opportunity to strengthen the system. When postmortems shift from allocating blame to investigating the systematic reasons why an individual or team had incomplete or incorrect information, effective prevention plans can be put in place. You can’t "fix" people, but you can fix systems and processes to better support people making the right choices when designing and maintaining complex systems.

— Site Reliability Engineering — Postmortem Culture: Learning from Failure

https://landing.google.com/sre/book/chapters/postmortem-cult...


Amazon is pretty strong on this front too, the most recent public example is the S3 outage and postmortem[1].

>Unfortunately, one of the inputs to the command was entered incorrectly and a larger set of servers was removed than intended.... We have modified this tool to remove capacity more slowly and added safeguards to prevent capacity from being removed when it will take any subsystem below its minimum required capacity level. This will prevent an incorrect input from triggering a similar event in the future.

[1] https://aws.amazon.com/message/41926/


This was address very well by a video posted on the Piper Alpha story yesterday.

https://news.ycombinator.com/item?id=14732404

https://www.youtube.com/watch?v=S9h8MKG88_U


While I agree generally with that sentiment, there's a key difference.

Airplane pilots are licensed, certified, trained, and regulated. There's a clear floor to who is allowed in the cockpit (barring extreme emergencies, e.g., incapacitation of a pilot).

By contrast, software is made available to pretty much the entire world. And it turns out that two thirds of all adults have "poor", "below poor", or no computer skills at all. Which is to say, the qualifications floor is nonexistent.

If you're designing a one-size-fits-all system, you've got to design for this. The results, I'd argue, are ... not particularly satisfactory.

I'm not saying "don't design for the user in mind", or "don't dismiss user error". But rather, than when your floor is zero, you're going to have a remarkably difficult challenge.

https://www.reddit.com/r/dredmorbius/comments/69wk8y/the_tyr...


They do, or at least the big-scale places who know what they’re doing do. When Gmail or aws-east-1 or something goes down for hours, nobody is fired: they figure out why it was allowed to happen and change procedures so it can’t happen again.


They do. That's what UX is all about. Not just UI, not just making thing possible or visual, but actually making the experience as smooth and frictionless as possible.


UX is the bane of usability (at least as practiced). E.g. We've had professional "UX" designers seriously contend that "cancel" buttons should be made to not look like buttons. The joke at a certain large company was that if the UX designers had their way every default button would be big and green and every other button would be invisible.

True usability is about helping people make the correct decision, not just being smooth and frictionless. (See Don Norman's classic example of fire escapes that send people into basements to be trapped.)


I'm a daily user of some of the most complicated engineering software on the market. Every single release promises "Easier to use!" but all they do is make the most basic beginner-level actions more prominent and hide all medium to advanced level important functionality behind 3 extra clicks.

The end result is a beginner can do a tutorial exercise in 20 minutes instead of 30, while any true day to day work in the software takes 4 hours instead of 2.


From the company's perspective, getting more beginner users on the software (and converting them to regularly paying users) is probably the priority.

That doesn't mean they couldn't put an "advanced mode" setting/option that makes the UI streamlined towards users like yourself, though.


Do you think this tradeoff between easy-to-start-using and power-use-friendly is intrinsic, a scale that designers need to choose where they want their software in it, or is it possible to hit both ends? Does anyone have examples of things they think address both beginners and power users adequately?


True. But as with any other discipline, it's about thinking about the intent and final goal, not just following a rule book containing arbitrary roles.


If someone walks into a glass door once, you can say they weren't paying attention. If more and more people start walking into the same door, there's something wrong with the door.


There was also SIA Flight 006 which crashed while taking off from the wrong (closed) runway at Taiwan[1], which was big local news in Singapore at the time.

[1] https://en.wikipedia.org/wiki/Singapore_Airlines_Flight_006


Mistaking runway 05R for 05L when both are parallel is more understandable though. It was also at night, in poor weather, and the airport had not blocked off the unusable runway (!) and did not have the gear to track aircraft locations on the ground.


I'm surprised there isn't more explicit tooling in the cockpit to stop that happening


As I understand it, planes are largely automated but the automated components will always defer to the pilots whenever action is taken. I would hope with the amount of training required to do that job that the pilot would be the half of that equation to defer to.


As I understand it (but I am not a pilot), that's true of Boeing planes, but not true of Airbus. Airbus makes the pilots defer to the automation.


Why in the world is this even a problem? Shouldn't what's a taxiway and what's not be indicated on maps or diagrams or something that pilots can see?


Because the pilot is almost never looking at a map on final approach. He is looking out the window, and in the dawn/dusk light, or with a setting sun in the background or inclement weather etc., a taxiway can look exactly like a runway.

Don't forget that almost all taxiways run parallel to the runway, for about the same length.

(NB: I used to be a commercial pilot.)

In most airports I flew into, the surface material for the taxiways was different from the runway, so sometimes the taxiway could end up looking brighter and more prevalent than the runway under certain lighting conditions. Yep, I have had moments of confusion when on long finals into an unfamiliar airport. Never to the point of actually ending up landing on the taxiway, but the confusion is a thing that pilots have to contend with.


Thank you! That raises the question, (a) why is there no kind of warning system for when you're about to land on the wrong runway (there's a GPS system in the aircraft that knows where you're going, right?) and (b) why is the pilot (or at least co-pilot) never looking at a map on final approach? Is it really that dangerous for anyone to take a quick glance?


Yes, autolanding, or if the pilot was using ILS (Instrument Landing System), then this problem would almost never happen, as they would be aware there was a problem.

However, most pilots eschew automation especially on short finals, and prefer the 'hand fly' the aircraft in so that they can maintain complete control over the aircraft. Not a bad thing, and pilots want to actually fly the plane at crucial times.

When hand flying on final approach, your eyes and senses are 75% outside the aircraft. All you are worried about is your airspeed, your rate of descent and whether the runway is remaining visible at all times. Your eyes are darting from your primary instruments in front of you to the runway outside, and your arms and legs are busy working the throttles, control stick and rudder pedals.

Maps and charts are well stowed away at this point. In fact, once you enter the main airport traffic pattern, they are put away as all the details should be memorised by then. At best, the pilot will have the approach plate on his/her control column. But this just gives the instrument approach paths and radio frequencies etc. and not really a detailed topography of the runways/taxiways.

Ironically, AFTER the plane is on the ground, the non commanding pilot will usually pull out the airport plate which details all the taxiways and routes to gates etc., especially if they are unfamiliar with the airport and have to find their way around.


I have to disagree about the maps and charts being stowed away at this point.

I personally can only think of one 121 certificated carrier in the US that isn't using an EFB setup. These are typically mounted to the side of the pilot and there's no reason at all they can't still be on and open to either the airport diagram or the approach in use. In fact I frequently do this and do reference it on approach to parallel runways and to reference the turn offs for taxi.

As this discussion progressed, the lack of progress in the FAA adopting technology was addressed. It seems to me that the FAA is completely missing the boat on tons of safety to be gained with these EFBs due to the bureaucracy. My carrier was recently certified for EFBs and the vendor has the capability to have GPS geo-referenced charts but because of the complicated certification process the airline chose to get certified without to save money and time. As part of that we also received devices without GPS so now there's no way it's coming until the next cycle of devices. Personally I can't understand why there would need to be additional certification for something GA pilots have been using for years now.


I am going to say you are probably more right than me. I haven't flown in over two decades, so things are bound to be different/better nowadays and procedures and safety improves.

Take my replies here with a grain of salt and as being 'old school'. :)


Fantastic explanation, and the question on my mind the entire time is "but why??"! Surely the copilot can look at a map (when I say map I don't mean a piece of paper -- I mean a digital one with GPS and everything) and see their trajectory while the pilot is landing, right? Like I'm imagining there should be something on the plane that shows them their trajectory and the runway information. If there is, why isn't it telling them when they're going the wrong way? If there isn't, why not? Is the technology simply behind, or is there a safety reason or something?


Ah, I think you are picturing something like a HUD (heads up display) that they have on fighter jets? That would certainly go a long way towards solving the issue, but commercial aircraft don't have a HUD display system (though I believe the 787 has a partial HUD display now).

Commercial aircraft have a HSI (horizontal situation indicator) located front and center on the panel in front of the pilots. This instrument presents about 12 distinct pieces of information to the pilot, but once again, on short finals, the pilots is mainly concerned with (1) airspeed (2) altitude (3) rate of descent on this instrument. All of which are displayed on the left and right edge of the HSI in the form of moving bars. The information in the centre with relation to position and orientation is discarded as unnecessary 'noise' under this extremely high workload.

You are right in that the co-pilot has to work in conjunction with the pilot to ensure safe flight. Indeed, in many cases, it was the co-pilot (or non flying pilot) that alerted the flying pilot as to an imminent danger. But that doesn't always happen either. Take the case mentioned elsewhere here of the worlds worst aviation disaster. In that scenario, the junior co-pilot of the KLM jet notified the Captain (who was one of the the most senior pilot in KLM at the time) TWICE that he thought the PanAm jet was still on the runway, only to be ignored.


Yes, I don't know the types, but any kind of display that can show the relevant information would seem viable in 2017 :-) so it seems the main answer to "why?" is just "because adopting such technology is abysmally slow" rather than because it's inherently a bad idea? (Thank you for all the responses again! They're excellent.) (Edit: just saw your other comment, please feel free to ignore this if it's redundant.)


Yes, because getting ANY type of new technology on airplanes certified by the FAA (as well as the relevant air safety authorities in every other country in the world) is a laboriously long, slow and expensive exercise. It is sad, but the bright side is that is seems to be getting better nowadays as compared to when I was flying decades ago.


Also, iPads have become a vector for bringing new tech into the cockpit, since it's not physically installed in the plane and therefore doesn't require certification. You can pull up charts, set courses and upload to the autopilot.


You can "upload" something from your iPad to the autopilot system without any kind of certification?


I have a feeling by "upload" they mean the iPad can display all the numbers that need to be manually punched into your autopilot.


This is actually kind of terrible. A compromised ipad could either compromise the planes actual vital systems for one, any time 2 systems are in communication a compromise is possible, and for two it could introduce a subtle numerical error.

I can't imagine a scenario where this ought to be allowed.


Sort of, at least in general aviation. Some of the newer avionics have bluetooth interface. For instance, popular GTN-series nav/comm can accept flight plans from Garmin Pilot software running on iPad.

Now, the iPad part is not certified, but the nav/comm (including software) is.


What you are describing is called PFD (Primary Flight Display). HSI is just a bottom part of it, basically combined heading indicator + CDI/VDI + (sometimes) moving map. But anyway, unless you are on instrument approach (or at least have it tuned in on your avionics), the HSI won't show you whether you are lined up with the runway or not.


I don't think a map or chart would necessarily solve the problem. The taxiway runs parallel to the runway, in the same direction, is the same length, and is similar in width.

Similar to how a map or GPS won't stop you from turning down the wrong way on a divided highway. Or how there have been many cases of people following GPS and turning onto railroad tracks that parallel roads. https://www.google.com/search?q=driver+turns+onto+train+trac...

It's not like it happens every day, so I expect there is some significant thought going into how to mistake-proof this particular problem.


When the GPS in my car shows two lanes, it clearly marks whether I should take the left or right one.


...but it sometimes detects your position as being in the other lane than where you actually are (or even a block away).


I suppose that a GPS in an airplane should always take the precision of the instrument into account. If it can't determine which lane it approaches, perhaps it should show a warning sign, and/or highlight the lane that should be taken.


We can use gps to guide munitions moving at a very high rate of speed to very small targets. I'm guessing missiles and planes have better gps than your phone.


That can get especially crazy during construction, and after new roads open.


> Surely the copilot can look at a map (when I say map I don't mean a piece of paper -- I mean a digital one with GPS and everything) and see their trajectory while the pilot is landing, right?

It's not like the pilot doesn't know there is a parallel taxiway. Of course there is. They would be (subconsciously anyway) looking for it to complete their mental map. It just went wrong in this case.

You wouldn't even have needed a fancy automated system to realise you were looking at a taxiway in that particular situation. There were four big aircraft on there, with position lights and taxi lights and everything. And apparently visibility was good. It was just a spectacular brain fart.

While the system you're suggesting might give better situational awareness, it might also be a dangerous distraction in other cases -- or be wrong for some reason. So more tools aren't automatically better.

In this case the existing system actually worked flawlessly: another controlling instance (the tower controller) discovered the error, took appropriate action, and all that happened was a 15 minute landing delay and a good story. Probably happens more often than we'd care to imagine.

> Like I'm imagining there should be something on the plane that shows them their trajectory and the runway information. If there is, why isn't it telling them when they're going the wrong way?

Well, there's the ILS (instrument landing system), but pilots like to land manually. IIRC it's recommended these days, just to remain in training. I suppose it's also fun.

Also, ILS might be wrong somehow (interference, technical defects, the pilot accidentally entering the data for the left runway when he was told to land on the right, etc).

So the truth is this was just human error, and that kind of thing just happens. You know the saying: if you make a system idiot-proof, nature invents better idiots.


He did notice and asked the controller if he really was clear, who then gave the goaround. At least that's my read of the story.


You're right, I misremembered.


x2. This is redundancy in action.


The copilot is also busy with checks and other tasks, it's not like (s)he's just with crossed arms watching the show

However yes, it's the copilot's job to double check what the pilot says and to warn if anything's not what it should be (like trying to land on a runway)


> it's not like (s)he's just with crossed arms watching the show

I mean I wasn't assuming that was the case either...


Why not put a big ass array of red lights to indicate where not to land though?


All you need is an universal (ICAO) visual indication for "this is a taxiway, do not fucking landing here". For example, a stripe of alternating red and blue lights.


The runway is where you do want to land.


Thanks, corrected.


I was going to ask about the ILS, which I assumed pilots always used for lining up their approach. I watched a friend of mine who was a pilot, punching in ILS codes on a training simulator and I remembered it myself years ago from Microsoft Flight Simulator 4. (now that I think about it, I think he even mentioned that he didn't often use ILS).

It seems like a pretty critical system for lining up an approach on the right runway. FS4 even had a training mode where it would display the ILS bars on the screen without needing to look at the instruments. You'd think some commercial airliners would at least put this in a heads up display, where it would be totally obvious you're lined up with the taxi way since the bar would be glued to one side or the other. Don't Navy pilots have a similar HUD for just their vertical approach angle?


Yes. I flew actual planes, and loved playing with MS Flight Sim too, and the number of times I WISHED we could have the same sort of heads up information on the real thing was quite funny.

(Also, would have loved SLEW MODE on the real thing, but that is a conversation for another time and dimension) :D


> most pilots eschew automation especially on short finals

Don't pilots have a legal requirement to manually fly a minimum number of landings per month?


Sort of.

A pilot is required to have at least 3 takeoff and landings in the type of aircraft he is to be operating in the preceding 90 days.

And I say sort of because an autopilot coupled ILS approach down to 100 ft above the runway still counts. This mean that as long as the pilot set up the automation correctly the airplane will have him lined up and on proper vertical path at 100 ft. He can disconnect autopilot and gently set it down.

So one, mostly automated, landing per month is all that is required.


What about an audio warning: "Alert! You are about to land on a taxiway!". Wouldn't that be useful?


Could be, but there have been many cases of pilots missing an audible warning while under heavy workload too.

Most notably the Adam Air(?) crash in Indonesia, where the crew were so intent on debugging a faulty minor flight computer that they simply didn't hear the the warning klaxon indicating that the autopilot had become disengaged and the plane ended up rolling over, entering a spin and crashed into the sea.


When flying visually (VFR), taxiway lighting and runway lighting are visually very different. Taxiway lighting is almost always blue, whereas runway lighting is white (with any displaced threshold marked with red lights). In daylight, the markings on the runway are unmistakably different.

I'm not instrument rated but my understanding is that with ILS, instrument approaches can handle multiple parallel runways precisely and therefore the pilot has the tools necessary to distinguish between a runway and taxiway when in instrument conditions. Someone please correct me if I'm wrong.

Let the investigation happen, but from the reported facts, this seems to be a pretty clear case of pilot error.

And I think you meant to say "raises the question" rather than "begs the question."


With all due respect, blue and white seem like terrible colors to pick if they are supposed to be clearly distinguishable.



I’m intrigued by the question of what you were hoping to add to the conversation with a Wikipedia link with zero explanatory text.

Did you mean “look, some people think popular usage has won out and beg the question is now a reasonable substitute for raise the question”? Or something else?


Haha, thanks! Will fix that last bit.


So many people use 'begs the question' as 'raises the question' now that it's a valid meaning for the phrase.

EDIT: To the downvoters: I don't think you understand how human language works.


Does not something wrong enough times doesn’t make it correct.

For example using “because” without a preposition doesn’t become correct just because Buzzfeed makes it popular.

People make grammar/useage mistakes not because they consciously want to change the language but because they don’t know any differently. It’s quite different than how slang enters a language. Begs vs. raises the question isn’t some kind of colloquial thing, it’s just a misuse. I get things wrong when the language frequently enough, but when it’s pointed out, I don’t continue doing it; in fact, I am happy for the opportunity to increase my precision with the language.


>Does not something wrong enough times doesn’t make it correct.

This isn't true in natural language. Do something enough times -- 'wrong' or 'right' -- and it becomes a part of the language. Like it or not.

Crack an Oxford English Dictionary sometime. Look up your favorite word. Notice that there will be tens of different definitions, including a historical trace of 'first uses' through semantic changes, for the single word.

>People make grammar/useage mistakes not because they consciously want to change the language but because they don’t know any differently

Consciously or not, they are changing the language. Language isn't a fixed thing with unbreakable rules. It is mutable. A language is however people use it; it isn't a thing to know in its entirety before using.


People don't have to consciously want to change the language for it to change. It's not like the differences between modern English and Victorian-era English are all because someone willed it. Usage dictates meaning, and I'd say the general public uses 'begs the question' as 'raises the question', whereas only people interested in philosophy use it as 'presume the answer' - essentially the latter version has become a sort of jargon regarding fallacies.

It's like the word 'irregardless'. As much as 'it isn't a word', it clearly is, because you know what is meant when it's said, and plenty of people say it.


'begs the question' is a bad translation of petitio principii, which is itself a bad translation from a greek text. The general usage of the term is the only correct interpretation. The phrase seems to be a trap for a certain category of pedants.


> Is it really that dangerous for anyone to take a quick glance?

Speaking as a private pilot, it absolutely is. Even in a Cessna you're going to be travelling at least 75 mph. Possible faster if the conditions are gusty. For the last 1/4-1/2 mile at least, your vision needs to be 100% outside of the airplane. Now if you need to do that in a Cessna at 75 mph with no more than 4 people on board, why wouldn't you also need to do in a 787 that lands at ~180 mph with nearly 300 people, or an A380 that lands at ~140 mph with over 500?


> Now if you need to do that in a Cessna at 75 mph with no more than 4 people on board, why wouldn't you also need to do in a 787 that lands at ~180 mph with nearly 300 people, or an A380 that lands at ~140 mph with over 500?

Because you have 1-3 other copilots who also have eyes and could be doing this instead of you...?


It would be like looking at a map of California and expect to be able to get around San Francisco - the aeronautical charts are generally for long haul navigation purposes. There are approach plates for instrument landings, but for landing there you'd be looking at your instruments, which you've dialed into the correct runway, not the plate, in order to land the plane. In this situation, however, I can only imagine the pilot was on visual approach because otherwise the plane wouldn't have been lined up to land on the taxi way.


Why can't they make taxiways more obvious (e.g. paint them bright red)? Seems like it would be a small cost for a lot of insurance against an accident.


See the Tests and Research section of the following NTSB report on a Delta incident where a plane landed on a taxiway at KATL. Note Also that the lights had been recently updated with LEDs from incandescents. Basically, the taxiway centerline was brighter than the runway centerlines and the colors of the lights were only apparent at 500ft.

https://www.ntsb.gov/about/employment/_layouts/ntsb.aviation...


With the setting sun just right, you wouldn't see the red, just reflected sunlight. There's no guaranteed solution for all cases, and aerospace visuals are some of the most heavily studied of any industry.


Runways are already very visually distinctive. An active runway at night is a river of light that you'd think would be unmistakable, and yet these incidents happen.

https://scaredflightless.files.wordpress.com/2012/09/approac...


Seems like a design flaw. Do any taxiways have markings etc. to make them more distinguishable?


They do. They have different lighting systems/colours etc. to differentiate them.

Taxiways generally have green lights along the centerline to guide aircraft rolling on the ground, but runways usually have white (bright) lights along the edges. There are times when even THAT causes confusion, because sometimes the taxiway centreline lights can look like the edge lights of the runway - especially if the light is refracting off a wet windscreen.

So, in the end the problem is generally avoidable, but if you are on finals at a really busy airport after a gruelling 20 hours trans oceanic flight, at night, in the rain, and the tower is trying to hurry you up to expedite traffic, you can make mistakes.


Perhaps this is a dumb question but is there any reason why the taxiway doesn't have HUGE red Xs going down it and the runway with HUGE green arrow going down? Sorta like what they do on bridges where the lanes can shift to allow more cares to travel in one direction but more obvious? They could even angle them so the planes on the ground see them differently or not at all.


Red 'X's on a runway usually denote an inactive or out of service runway.

They ARE actually quite different in terms of lighting, width etc. and 99.9% of the time there is no issue telling them apart. Runways also have extra approach lights etc. at night to really make it clear where you should be pointing the nose.

(NB: Check out the video posted elsewhere in this thread of the cockpit view of a 747 landing at SFO at night. It is pretty clear which is the runway and which is the taxiway).

However, it is those 0.01% of the times where the weather is bad, or you are landing into the sun or the traffic is really congested and you are trying to talk on the radio at the same time etc. where mistakes can be made.

In this particular scenario in the OP, I am assuming that having 4 heavy aircraft lined up on the runway pointing at the landing plane, then 4 sets of bright landing and navigation lights on the taxiway could have looked like runway lighting, and disoriented the Canada Air pilot? Just outside speculation here, but stranger things have happened.

It's like the case of the Air New Zealand CD-10 crash into Mt. Erebus in clear weather. Non pilots were incredulous that a plane could fly into the side of a mountain in clear daylight weather, but the visual trickery played by bright snow on a slope actually fooled ALL pilots on board that they were flying down a valley instead of into an upward slope. [0] (A badly programmed navigation computer didn't help at all.)

[0] - https://en.wikipedia.org/wiki/Air_New_Zealand_Flight_901


The a/c on the taxiway will not have their landing lights on while pointed downwind.

They turn them on when theyre cleared to enter the runway.


Just a very naive question, would not it be possible for the taxiway lights to only be visible from the ground?


A good concept in theory, but bear in mind that the cockpit of a 747 or A380 is something like 2 or 3 stories above the ground, in terms of height.

To be able to see a taxiway light 50m in front of the plane, the light will have to be angled up to an extent that a plane 500 feet in the air a mile away will also be able to see it.

Not putting down your idea at all - anything workable that will improve flight operations should be considered.

Trivia: Speaking of lighting assistance, Did you know one of the best inventions out of Australia is the T-VASIS landing system [0] that is in use at nearly every major airport in the world?? Oh, and we invented the DME too [1], in the aviation world... :)

[0] - https://www.dst.defence.gov.au/innovation/tee-visual-approac...

[1] - https://en.wikipedia.org/wiki/Distance_measuring_equipment


A good concept in theory, but bear in mind that the cockpit of a 747 or A380 is something like 2 or 3 stories above the ground, in terms of height.

Fun fact! The A380's flight deck isn't that high off the ground. It's exactly the same height as the A330 and A340, part of an effort to reduce differences and cut down on the amount of new things pilots would have to deal with to train on the type.

This is also why the A380 has such a pronounced "forehead" -- the much lower flight-deck height (compared to a 747) means there's a lot of plane above that.

(and bonus fun fact: the 747's flight deck is way up top not for visibility, but because Boeing anticipated supersonic planes would take over the passenger market; the 747's high flight deck was meant to accommodate converting the plane to cargo use, so that the whole nose could swing open for loading and unloading)


Australia is also responsible for "black box" flight recorders, which are one of those things where it's really hard to appreciate in hindsight why we didn't mandate them much sooner.


Seems like a very good argument for autopilot landings.


And yet, when the Asiana accident happened the complaint was that the pilots were relying on automation too much and didn't know how to properly hand-fly the airplane anymore.

Not all runways are equipped for ILS landings. Sometimes the ILS equipment gets taken out of service for maintenance. And even autoland has its limitations.


You might enjoy this classic video:

https://www.youtube.com/watch?v=pN41LvuSz10

Just be sure to make a note of the video title so you can find it again -- copies of it tend to get taken down, since American Airlines got in some trouble after other parts of this training course were blamed for the crash of AA flight 587:

https://en.wikipedia.org/wiki/American_Airlines_Flight_587


> American Airlines got in some trouble after other parts of this training course were blamed for the crash of AA flight 587

More specifically, the pilots manipulated the rudder on that airplane so aggressively that it sheared off in flight. They were trained to react aggressively in the "Advanced Aircraft Maneuvering Program", which this video is a part of. (There are also related videos that I'm going through now that are more relevant to this particular incident; https://www.youtube.com/watch?v=WfNBmZy1Yuc, etc.)

BTW, if AA is indeed DMCA-ing these videos, that's pretty interesting. Copyright was designed to incentivize the progress of science and the arts -- not to make large corporations look less bad after they unintentionally kill a few hundred people. Oops.


Ah, here's the wake turbulence one: https://www.youtube.com/watch?v=FxXwqAm1a-Y


From the sound of things, this particular disaster hasn't happened before, even though it's conceptually easy to imagine how it could. Is that because it's easy for the controllers on the ground to wave somebody off if they're going the wrong way, or is it really because we're just lucky?


Side question: do you think one day commercial pilots aren't necessary anymore, i.e. totally unmanned commercial airlines? If so, how far away in the future are they?


There has been some talk of remote piloting (like drones,) but personally, I want whoever is flying the plane to have some skin in the game. Unmanned - fully autopilot aircraft are certainly possible and I sure Boeing probably has a Skunkworks looking into it, but I’ve seen enough source code over the years that I would have a hard time trusting an autonomous airplane unless they had escape pods. Autonomous airplanes seen to be solving a problem that doesn’t seem critical to solve – given the statistically exceptional safety record of commercial air travel. Pilot error is a very rare cause of airliner crashes.

I think electric airplanes powered by Mr. Fusion mini nuclear reactors would be the future I’d like to see!


>Pilot error is a very rare cause of airliner crashes.

Is that overall, or as a percentage of all airliner crashes? Because another commenter stated that human error is responsible for most of the crashes.

https://news.ycombinator.com/item?id=14741726


It seems like an easy problem to solve. Line the taxiway with red/blue/green or whatever color is appropriate lights.


(pilot here) Yes, they are very well shown on maps, but it can be hard to map your diagram to what you're seeing, especially if it's raining or if it's at night, and even more if you're tired.

I never made the mistake, but can see how somebody in bad conditions would.


Thanks! But why do you even have to map your diagram to what you're seeing? Isn't there a GPS system that shows you exactly where you are on the map and where you are going to go in the next few minutes? It doesn't seem like there should be any mental or visual processing to figure out that you're heading toward the wrong runway, right?


Even setting aside the GPS/tablet/etc. question, I think you'd probably be astonished to learn how simple and how old the technology of automatic/instrument landing is.

Instrument landing systems date to the 1920s, a time when flying at night, or above cloud tops, was incredibly dangerous.

Imagine setting up a couple of directional radio antennas at the end of the runway. One broadcasts short beeps with long pauses (beep-----beep-----beep), the other broadcasts long beeps with short pauses (--beeeep--beeeep--). Set up the antennas so that if you're lined up horizontally with the center of the runway, the signals merge into a continuous tone (beeeeeeeeeeeeeeeeeep).

That's more or less how instrument landing systems still work today. Modern ones have more antennas and coordinate you both vertically (on the correct slope to touch down at the start of the runway) and horizontally, but the whole thing is still based on directional radio signals that you pick up from your plane, and a published set of information for each airport (the "approach plate") telling you what frequencies to listen for depending on the runway you want.

Airliners can be programmed to "autoland" based on this information, but it requires some setup and also requires the pilots to be ready to take over at a moment's notice (if, for example, controllers at the airport decide to have the plane land on a different runway).


It's a matter of scale. Even on a modern HSI, the difference in distance between the runway and the parallel taxiway is probably the width of the indicator icon. Very hard to see on instruments. Much easier to see by looking out the windscreen.


I can't tell if my expectations are just too high, but the impression I'm getting from all your answers is that pilots just don't have a dynamically updating (i.e. digital) map. It seems like everything is a bunch of numbers the poor pilots have to crunch or ticks that they have to count correctly or sheets of paper they have to pass to each other with diagrams. Why in the world is the system so ancient in 2017? Google Maps on my phone can show me where I am within 10 meters and where I'm going for the next 10 minutes, and it automatically zooms in and out at turning points... why can't an airplane have a display that shows them where they are and where they're going within the next minute?


Ironically, it is mainly because of reliability. Every system on an aircraft HAS to have double or triple redundancy by law, and a lot of these systems ARE antiquated by usual consumer standards.

A lot of pilots these days have iPads in the cockpit to assist with this, but in nearly all airlines and aircraft types, these are unauthorised devices that are not part of the certification. Generally they are used for non critical things like manuals or checklists, but I know of pilots that use them for situational awareness as well. In an accident though, this may work against them, badly.

Yes, it is the old legal and liability issue. Aircraft systems should be upgraded, but the cost of upgrading an entire fleet is prohibitive for most airlines that are already operating on the smell of an oily rag. New generation aircraft are getting better at it though. Like I mentioned before, I believe the 787 now has a HUD of sorts, which is long overdue.


Hmm, Electronic Flight Bags are now a regulator-approved thing for manuals/other paper products.


Aw man, sad to read this but thank you.


You know what else Google maps does? It quits working at random times and behaves unpredictably in low precision GPS scenarios.

GPS units certified for aviation are tested to edge cases for usability with predictable and clearly indicated failure modes. This slows down new tech, but it's critical.

Even auto zooming on gmaps seems like a no-brainer, except for the times where the auto zoom into a trivial maneuver (continue onto road) occludes the difficult immediately following procedure (take correct exit out of 4 within 50 meters).


> You know what else Google maps does? It quits working at random times and behaves unpredictably in low precision GPS scenarios.

OK, so you're saying airplanes don't already have GPS systems that work better?

Or are you claiming I said "Airbus and Boeing should literally install Google Maps in the cockpit"?


Okay, correction. Airplanes don't have GPS systems that work better at the level of reliability required. "It works most of the time, except it sometimes doesn't" might be sufficient when you can stop at the roadside, but doesn't quite cut it in the air.


Okay so let me get this straight: you're telling me that passenger airplanes currently fly by dead reckoning or stellar navigation or ground-based triangulation or something else? When a pilot doesn't know where he is, he doesn't have any kind of certified GPS-based system handy to tell him?

And moreover, even beyond GPS: how the hell can a plane's navigation system be capable of (and certified for!) landing the monster under autopilot, and yet not be able to tell the pilot its own location within the accuracy of a few feet reliably? I literally do not understand how what you're saying makes any sense.


Automatic landing systems rely on ground support by way of microwave signals from transmitters installed near autoland-capable runways. There's no general position information, and the airborne part of the system can't operate independently of the part on the ground.

Civilian GPS signals are limited in terms of position accuracy, too. I believe the CEP is ten meters. That's not bad, but it's not good enough to land an aircraft. Altitude information from GPS is (IIRC) either nonexistent or severely limited, too. About any aircraft with a glass cockpit is going to support a moving map display, and those do see use - but, as a couple of professional pilots in this thread have noted, during final approach the main concern with regard to aircraft position is relative to the glide slope and the runway, and a moving map has nothing to do with any of that.

On a more general note, it is remarkable to me that so many otherwise apparently sensible software engineers seem to regard aviation as a problem trivially susceptible of perfect solution - every time we here on HN discuss any sort of mishap even peripherally involving any aircraft, the same suggestions invariably arise around automation, various schemes of runway lighting, cockpit lighting, instrument augmentation or replacement, pilot augmentation or replacement...

One would tend to imagine that the history of our attempts to perfect our own craft - including those attempts which we who build and maintain software make anew every day - would give us cause for humility on the subject of fields other than our own, about which in the main we know next to nothing.

Imagine five hundred airline pilots confecting an ad-hoc, long-distance postmortem of the recent us-east-1 incident! You'll have to imagine it, because it did not happen - and it is rare at best in my experience for pilots, because they are skilled in one highly complex and technical field, to imagine they can speak authoritatively in the context of another. Perhaps we might profit by their example.


Thanks for the detailed response.

> Automatic landing systems rely on ground support by way of microwave signals from transmitters installed near autoland-capable runways. There's no general position information, and the airborne part of the system can't operate independently of the part on the ground.

Yes, I understand the landing portion has other kinds of support. However, I don't understand how it can not have the positioning information we need, because {see next response below}.

> Civilian GPS signals are limited in terms of position accuracy, too. I believe the CEP is ten meters. That's not bad, but it's not good enough to land an aircraft. Altitude information from GPS is (IIRC) either nonexistent or severely limited, too. About any aircraft with a glass cockpit is going to support a moving map display, and those do see use - but, as a couple of professional pilots in this thread have noted, during final approach the main concern with regard to aircraft position is relative to the glide slope and the runway, and a moving map has nothing to do with any of that.

This seems to contradict with what I read [1]. See this quote, for example:

Generally, the pilot will handle takeoff and then initiate the autopilot to take over for most of the flight. In some newer aircraft models, autopilot systems will even land the plane.

OK, so I don't have much of an expectation for older plane models, but my interpretation of the above is that in newer models, autopilot need not disengage before landing and require manual intervention in order to align the plane with the correct track (barring bad weather or other unusual situations like bird collisions, etc.). This is supported by the fact that they later explicitly mention that autopilot occasionally disengages. So it seems clear in normal situations autopilot has plenty of positioning available to it, enough to find the runway and locate the plane on a display of some sort. That goes pretty clearly against what you said. Am I missing something?

> On a more general note, it is remarkable to me that so many otherwise apparently sensible software engineers seem to regard aviation as a problem trivially susceptible of perfect solution

I hope this isn't referring to me, because I've been trying pretty hard not to give that impression (which I don't have). I never suggested anything about aviation perfection in general. I'm specifically talking about this particular kind of problem, because it seems to me that with current technology, pilot errors of this kind should be completely avoidable using current technology and, basically, non-problems in the first place. (Again: note that I said these types of pilot errors should be avoidable. I didn't say all faulty landings on the wrong tracks should be unavoidable.)

In other words, nowhere did I suggest that I think airplanes can fly or land themselves perfectly in unfavorable conditions. But this was quite a favorable condition for an automated system. And, as a computer scientist, what seems ridiculous to me is the idea that "Oh, but this system you just described won't work if there is a hurricane and there are turkeys getting rammed through our engines while the pilots are asleep and ATC happens to be on strike in the middle of a nuclear holocaust, so let's "be conservative" and never approve it because it's clearly going to make things worse on average".

[1] http://www.cnbc.com/2015/03/26/autopilot-what-the-system-can...


> OK, so I don't have much of an expectation for older plane models, but my interpretation of the above is that in newer models, autopilot need not disengage before landing and require manual intervention in order to align the plane with the correct track (barring bad weather or other unusual situations like bird collisions, etc.).

What is your definition of manual intervention? Pilots get updated instructions from the tower - the GPS path of the flight within 10 m is not programmed from the beginning due to weather issues, turbulence, traffic at the terminal ends, etc. The pilots hands may not be on the yoke, but they certainly are sending changes to the flight computer throughout the flight.

> So it seems clear in normal situations autopilot has plenty of positioning available to it, enough to find the runway and locate the plane on a display of some sort. That goes pretty clearly against what you said. Am I missing something?

Autopilot landings require a Cat III approach. There are currently no GPS (also known as GBAS for Ground Based Augmentation System) Cat III approaches approved in the US. The autopilot when landing is not using GPS for final approach. The pilot has pre-programmed in the waypoints labeled in the approach plate for the specific runway approach they've been told to take, and then they will switch over to the ILS approach.

The tone of many comments here (yours too) call out people who actually know how the system works and question them. The person you're trading comments with has said twice that GPS is not responsible for the autolanding portion of the flight. They even gave a summary of how instrument landing works - microwaves transmitted on specific frequencies in a specific pattern. You twice try to refute it. And then in your last paragraph you do exactly what he says the software engineers here do and you take offense to!

> sensible software engineers seem to regard aviation as a problem trivially susceptible of perfect solution

> And, as a computer scientist, what seems ridiculous to me is the idea that "Oh, but this system you just described won't work if there is a hurricane and there are turkeys getting rammed through our engines while the pilots are asleep and ATC happens to be on strike in the middle of a nuclear holocaust, so let's "be conservative" and never approve it because it's clearly going to make things worse on average".

Landing a big aircraft is not the easiest thing in the world, if only because the fate of hundreds of people rest in your hands. If you have a system that is designed to cut out the human component, it has to be all or nothing. As we learned from Asiana 214, when pilots have no actual practice doing something even in the absolute best of conditions and still cause loss of aircraft and life, how are they expected to perform when everything is going against them at the exact moment autolanding fails? Everything about flight training is preparing for the worst case, and practicing your skills over and over and over. Complacency can kill people when the margin of error between life and death is razor thin.


> What is your definition of manual intervention?

I was thinking of autopilot disengaging, but that's not really important here. I'll go along with what you just said.

> Pilots get updated instructions from the tower - the GPS path of the flight within 10 m is not programmed from the beginning

not in the beginning... so it is later?

> due to weather issues, turbulence, traffic at the terminal ends, etc.

Uhm, "traffic at terminal ends" suggests the real problem is that the correct path is not known in the beginning, or that autopilot might not be able to avoid collision on its own... which is quite a bit different from the plane being unable to locate itself accurately and follow the correct path even if it were known a priori. Are we even discussing the original issue at this point?

> Autopilot landings require a Cat III approach.

I have no idea what that means. I'm not sure what gave you the impression that I know what that means either.

> The autopilot when landing is not using GPS for final approach.

> The person you're trading comments with has said twice that GPS is not responsible for the autolanding portion of the flight.

> You twice try to refute it. And then in your last paragraph you do exactly what he says the software engineers here do and you take offense to!

I think you didn't read my last comment carefully because, as I already said, I understood this. My problem is whether GPS is accurate/reliable enough to lead the plane to the place where the next system can take over, which to me implies GPS is already certified to be accurate and reliable enough to get the plane near the correct runway. Read it again. There shouldn't be a single sentence there where I "refute" the microwave transmissions or claim GPS is actually used on the final approach.

> If you have a system that is designed to cut out the human component, it has to be all or nothing.

Wha..? Autopilot isn't perfect either, and can disengage in various situations that it can't handle, but they approve it and pilots manage to use it just fine. When it's GPS's turn, suddenly it has to be 100% perfect?

And when did I ever suggest you have to cut out the human component? For goodness's sake all I'm asking for is a little display with a map that shows where the plane thinks it's going. That's "cutting out the human component" to you?


> For goodness's sake all I'm asking for is a little display with a map that shows where the plane thinks it's going.

Any commercial aircraft with a glass cockpit, which at this point is ~all of them, already has one of these.


I mean including information/labels like "taxiway XYZ" that could make a stupid mistake like this obvious. Or are you saying they already do this?


No, they don't already do this. As 'phdp already explained, there are no instrument landing systems installed in the US which include GPS augmentation. So, while the moving map will show the same position information as at any other time when the aircraft's GPS receiver has sufficient signal, it's going to look something like this: http://www.stratomaster.eu/lignes/mgl/photos/enscr4.jpg

Meanwhile, the ICAO approach plate for SFO's runway 28R looks like this: http://redwoodva.net/lib/skins/en/images/events/charts/ksfo_... - trivially simple to comprehend at a glance, I am sure you will agree!

As far as "stupid mistake" goes, you sure do seem quick to judge professionals in a highly technical field totally unrelated to your own, and of which you've made clear you are happy to preserve your ignorance. Were I you, I'd hope my own errors meet with a greater extent of charity than that precious little you see fit to mete out. But that's your problem, not mine. Good luck with it.


> As far as "stupid mistake" goes, you sure do seem quick to judge professionals in a highly technical field totally unrelated to your own

The heck? Everyone makes stupid mistakes. Hell, I make more of them than a lot of people I know. That's why there are procedures and checklists and redundancies and automated systems -- to prevent stupid mistakes, evne by the best people. Where was I ever judging the pilot for heaven's sake?! Maybe you could be a little more charitable with how you judge people?


I mean you've already said you don't know what you're talking about ("I have no idea what [Cat III] means.") but you're totally cool with taking a confidently authoritative tone on it anyway, I'm not sure what other conclusion anyone should be expected to draw.


> I mean you've already said you don't know what you're talking about ("I have no idea what [Cat III] means.") but you're totally cool with taking a confidently authoritative tone on it anyway, I'm not sure what other conclusion anyone should be expected to draw.

...Did you come here just to fuel flames and burn people, or are you here to have a legitimate discussion about the subject?

You're totally cool being literally in ad-hominem territory at this point and you're lecturing me about not judging people I never even judged?


Is it really ad hominem to draw uncomplimentary conclusions from your evident disinterest in addressing substantive criticisms of the argument you're advancing? I don't think it is. Perhaps I'm wrong about that - but what else are you giving me to work with?


> Uhm, "traffic at terminal ends" suggests the real problem is that the correct path is not known in the beginning, or that autopilot might not be able to avoid collision on its own... which is quite a bit different from the plane being unable to locate itself accurately and follow the correct path even if it were known a priori. Are we even discussing the original issue at this point?

Your thesis of your statements is that it is ridiculous that there is no moving map for pilots to see on the airplane. You've been told directly by some commenters that there is (tuxer), and others, including me, have said that GPS is not the way to land a plane.

>I have no idea what that means. I'm not sure what gave you the impression that I know what that means either.

I mean this in a positive way, but you should look it up on wikipedia. There are many great articles about the systems in place for instrument approaches and landings, and you may learn something interesting for a quick 15 minute investment.

> My problem is whether GPS is accurate/reliable enough to lead the plane to the place where the next system can take over, which to me implies GPS is already certified to be accurate and reliable enough to get the plane near the correct runway. Read it again.

You call us out for dismissing your idea (And, as a computer scientist, what seems ridiculous to me is the idea that "Oh, but this system you just described won't work..."), which to mean seems to be some sort of GPS en-route to to landing automated system. This idea has been informed by your inaccurate reading of a CNBC article (So it seems clear in normal situations autopilot has plenty of positioning available to it, enough to find the runway and locate the plane on a display of some sort. That goes pretty clearly against what you said. Am I missing something?). The en-route exists but can often change from the time the plane leaves the ground to when it gets within 50-100 miles of the airport, at which time it might be disengaged and switched to VOR based navigation. The landing by GPS does not exist because it is a lot less accurate than the existing systems.

This branch of the thread is about auto landing, and you were talking about how it's absurd GPS is approved for automated flying. Given that GPS is used for en-route navigation and not landing, the assumption was that you were proposing GPS landing systems. That is what my comment is about. And yes, having autopilot disengage at 50 feet above the ground when the pilot is not expecting it can be fatal. I would say that for the landing stage it has to be all or nothing. And you've been suggesting cutting out the human component by proposing an system that goes from take off to landing without manual intervention! Even if there is still a pilot in the cockpit, it still takes a few seconds for the brain to spin up to take over a task from the computer.

It's awesome that as someone outside the aviation industry, you're curious about how it works. Your incredulous tone and sense of superiority (As a computer scientist, as if we should automatically and uncritically defer to your opinion, and I say that as a programmer) is a bit off-putting. If you had just done the basic amount of research you could have come back with a list of questions such as:

- Is GPS used to navigate planes from take off to landing? What else is used?

- Why was the pilot in this incident not using automation to land the plane? How often does this happen?

- What is the procedure for switching between different navigation technologies at different points of the flight? I know that take offs and landings can be manual, but when does autopilot kick in?

- Why is GPS not used to land planes?

- What equipment to pilots use in the cockpit? If they are not the latest and greatest, why?

We could then have had a proper discussion surrounding the need for backwards compatibility, the rolling out of ADS technology, how its absurd we still use voice over radio as a primary way of relaying commands, etc. Pilots and others in the aviation industry generally do believe that a lot of the technology guiding our largest planes is antiquated, but you trivialize it without understanding the full context.


>The tone of many comments here (yours too) call out people who actually know how the system works and question them.

Lack of enough common frame of reference that the ability to communicate is almost totally inhibited from the word go. It reminds me of the Feynman magnets youtube video. The interviewer asks Feynman to explain the attraction repulsion sensation and Feynman admits any correct answer the interviewer will not understand because he doesn't understand any of the basic prerequisites of having a conversation; and any answer he gives the interviewer would understand is cheating him out of the correct answer.


Seriously? From here, it looks as if you're doing your best in refusing to understand. Here's a hint: context. If you're en route, even an approximate position within hundreds of feet is great for navigation; please stow your straw men back where you found them.

In this case, the issue is with landing, where you need a precise position; "probably tens of feet, when it works" is exactly the sort of accuracy that's not good enough. As for "know where it is and land" - that's already there, is called Precision ILS, and uses no elements of GPS whatsoever.


The issue is you're treating this as though (1) cruising can be done on autopilot via GPS because it doesn't need much accuracy, (2) landing can also be done on autopilot because we have more accurate systems, but (3) the transition between the two requires manual intervention because the plane can't reliably locate itself accurately enough to get in the right position for landing systems to take over.

But that simply doesn't seem to be the case (in normal weather, which we had here). See my reply to a sibling comment here for a link. It seems that in normal conditions planes are capable of doing it all in one go, which means they are capable of accurately and reliably locating themselves. Nobody is expecting these to work in extreme conditions like bad weather or bird collisions, but in those conditions autopilot can and does already get disengaged (whether automatically or manually), and this could be done the same way. It's not like we forbid autopilot entirely because it isn't 100% perfect, so why not apply the same standards here?


Nope. (3) The transition between the two requires manual intervention, as those are very different flight modes, using different systems and there's no automagic way to switch between them; the quote from the linked article is an oversimplification akin to "computers can do almost anything - therefore what do we need programmers anyway?"


Oh, and aircraft DO have moving maps etc. now, but these are usually dialled out to show a range of hundreds of miles in cruise, and are not usually adjusted to show distances in mere metres when on final approach.

Once again, because these displays are usually on the centre floor console or located below the HSI, they are outside the 'scan zone' of a pilot on short finals.


In their defense, I would guess that making such a system 100% reliable and unintrusive may be a lot harder than we realize. It's not uncommon for Google Maps to be off by a few blocks for 10 seconds or more, and that could very easily be fatal if you're using it to land an airplane.


Are you suggesting their current GPS systems have that kind of issue though? I'm just asking for an interface to be added, not a entire concept of GPS functionality to be added. I'm assuming the latter is already used. It's not like I was suggesting they use Google Maps.


Indeed. GPS (and friends) are a best-effort affair - works great, most of the time.


There is, if you use it. In this case they were doing a visual approach , where you use eyesight in order to line up and land, because you have seen the runway. People do visual approaches in SFO as they are necessary to land 2 aircraft at the same time on the parallel runways ( they're like 30ft too close for parallel approaches on instrument ). It is still recommended to even in a visual approach, turn on the instrument approach systems ( for that exact reason ) but it looks like it is not mandatory for that airline.


If you watch any 28R approach video for SFO on YouTube, you'll be even more surprised. Because there is no way you can mistake the taxiway for the runway. There is a huge array of lights pointing the pilot towards the runway.

I would imagine this would be more of a problem during the day because the lights are not as bright compared to the ambient light.

I would think the best way to get this detected early would be to integrate some logic into the ATC radar. As the plane gets closer to the runway (or taxiway!), it should be easy to tell where the pilot is going by looking at the track and issue an automated warning.


There's an mp3 of the radio chatter here:

https://forums.liveatc.net/atcaviation-audio-clips/7-july-ks...

> Audio from the air traffic controller communication archived by a user on LiveATC.net and reviewed by this newspaper organization showed how a the confused Air Canada pilot asks if he’s clear to land on 28R because he sees lights on the runway.

> “There’s no one on 28R but you,” the air controller responds.

> An unidentified voice, presumably another pilot, then chimes in: “Where’s this guy going. He’s on the taxiway.”

> The air controller quickly tells the Air Canada pilot to “go around.” telling the pilot “it looks like you were lined up for Charlie (Taxiway C) there.”

> A United Airlines pilot radios in: “United One, Air Canada flew directly over us.”

> “Yeah, I saw that guys,” the control tower responds.


The "Where's this guy going" unidentified person on the channel prevented the worst accident in aviation history. Great Job! Give that guy a medal and a movie.


It's likely that the controller would've seen it as well after the Air Canada pilot indicated that he saw planes on what he believed was the runway.

Even if not, the pilot would've probably aborted the landing since he saw the other aircrafts. So it was certainly a dangerous situation but I doubt that a crash would've happened without that pilot's comment (it was certainly helpful though).


Controllers in the tower do not have a good visual perspective to see runway alignment. I don't think they would have caught this.

At night, there are many visual cues to see the runway environment - it sounds to me like this complacent pilot ignored many red flags and was about to drive his plane on top of those on the taxiway.

A big heavy airliner can't just stop its decent instantly; it's a good thing that pilot on the ground chimed in when he did.

I betcha the landing pilot won't have a job pretty soon.


When you're descending at a rate suitable for human cargo in good weather there's plenty of room to maneuver.

A C-5 that's trying to drop out of the sky ASAP before anyone can shoot at it is a different story.

The pilot and copilot were clearly in WTF mode since there were planes on what they thought was the runway. If nobody had spoken up it would likely have gone back and fourth between them and the tower a few times ("are you sure the runway is clear?") and in all likelihood they would have caught it. If they didn't the pilots would have likely requested to go around. Backing off of what you're doing and assessing the situation when anything is not quite right is SOP in every facet of aviation.


But they have radar and usually extended centerlines. That should've been clearly visible for him on the screen.


Radar displays are not going to accurately display a displacement of 150m. They're set up for broader area surveillance.

Edit: here's a good example of a terminal radar display. The two parallel diagonal lines are the extended centerlines of two runways that are about 1570m apart (Athens airport, LGAV).

https://www.hvacc.gr/site/images/content/events/2003/athens-...


And that's the spacing between the runways. There is less space between the runway and the taxiway.

http://flightaware.com/resources/airport/SFO/APD/AIRPORT+DIA...


Yeah. When reading about modern air disasters, you often hear that five different things had to go wrong at once for them to happen. In this case, one or two things went wrong, the rest of them went right, and everything was fine.


This is spot on. The strength and weakness in doing something as complex as safely landing an airliner full of people is all in the capability of the human mind to use technology. Especially in flying, I think (I did this for a career, a whole other career ago) it's easy to have everything going smoothly, then some "minor" thing be out of expectation, but hey things are going smoothly, so dismiss the minor thing because here's this other thing that does look just right, and ... and ... suddenly several mistakes have compounded.

It's sometimes harder when there's nothing impeding you at all to do everything right because the routine-ness of habit takes over. Being busy (but not overwhelmed), while more mentally and physically tiring, is sometimes easier, because you pay attention to the right things at the right time.


This is true in all manner of domains. I've never flown but I can remember a number of times I've made (fortunately relatively inconsequential) mistakes that caused me to face-palm afterwards. Why? Not so much that I made a mistake. But that I could recall clearly a number of observations that I made but dismissed because they ran counter to what I "knew" was the reality of my situation.


This is like Sully all over again, but with only seconds to extract story from instead of minutes!


"Taxiway", coming to theatres near you soon. Directed by Clint Eastwood. Starring John Malkovich as The Pilot, Tom Hanks as the "Where’s this guy going?" guy, and Dave Bautista as the taxiway.


Yeah but casting Pauly Shore as the controller? Bold choice.


Listen to this recording:

https://www.youtube.com/watch?v=SgPuyzogFuI

It's from a Delta flight a few years ago that slid off the runway at LaGuardia in snow. The action starts about 5 minutes into that recording; Tower has just set up another incoming Delta flight to land, and is trying to confirm Delta 1086 has cleared the runway. Delta 1086 is poking its nose out over the water at this point, and the controller can't see it.

At around 5:56 a ground vehicle calls in to ask permission to cross the runway and gets it. Then the ground vehicle sees what's happened (Delta 1086 slid off the end of the runway), and this is where it gets interesting, because you see very quickly two important things:

1. Trusting the report: the guy up in the tower does not have a perfect view, and in fact in this incident he can't see what has happened to this Delta plane. He's getting an unsolicited report from a ground vehicle, but he believes it and acts immediately on it. If the report's mistaken, worst outcome is some planes circle a bit more before they finally land. If the report's right, though, the worst outcome is planes trying to land on a crash site.

2. Division of responsibility. From the moment the crash becomes known, it's the job of the emergency/rescue teams to figure out what's happened and deal with it. The guy in the tower probably desperately wants to know more about what's going on, but he's got planes stacked up waiting to land, and his curiosity is going to have to wait. Beyond getting confirmation of a couple unusual orders, Tower just lets the folks on the ground do their job, and sticks to doing his.

Here's a rough annotated transcript (timestamps are from the video), since I know people complain that ATC recordings are hard to make out:

6:08: Delta 1086, Tower? (trying to contact the plane that's just gone off the end of the runway -- Tower still doesn't know what's happened)

Tower, call 100, Runway 13 is closed. (ground vehicle has seen the accident)

Tower, red team to go onto 13.

Tower, you copy? Call 100, Runway 13 is closed.

Call 100, you said Runway 13 is closed? (Tower confirms what he's just heard)

Affirmative, 13 is closed.

Team red, Tower?

Tower, you have an aircraft off the runway.

6:45: Delta 1999, go around!

1999, going around.

6:50: The airport is closed. The airport is closed. We've got a 34. (ground crew saying this is bad enough the airport needs to close)

Call 100, say again?

6:59: Tower, you have an aircraft off 31 on the north vehicle service road, please advise crash rescue, LaGuardia Airport is closed at this time.

7:12: Good afternoon, Tower, Delta 2522's on the ILS for 13 (another Delta flight is lining up to land on the runway where the crash happened* -- they can't hear what's happening below)

Delta 2522, LaGuardia Tower, go around!

Go around, Delta 2522. (pilot confirms that he's going around)

From there on out, it's just Tower giving instructions to other planes on what to do, and a report from the ground to tell the pilot of the crashed plane (if he does get on the radio again) that the plane is leaking fuel from a ruptured wing.

Now: what if the ground vehicle hadn't gone out there? Or hadn't seen the crash in time, or hadn't been able to get a report to the tower in time, or the tower had hesitated a bit more in accepting the report and starting to reroute planes? A similar problem to the SFO incident, only instead of an occupied taxiway it would've been an occupied runway (and one that had already caused one plane to slide off in the snow, and now had emergency vehicles converging on it).

The point is, though, that this isn't necessarily a miracle or a lucky escape -- everybody is involved in ensuring safety, and that's what happened in both cases, providing extra layers of watchfulness which averted much more serious trouble.

* The runway is referred to as both "13" and "31" at different points; runways are numbered according to compass heading, so "13" means it's aligned to a heading of 130 degrees. The dual numbers are because you can take off or land from either end; the other number is always +/- 18, since it's 180 degrees around from the first one. In this case, the designation of the runway is 13 from one end, and 31 (for 310 degrees, 130 + 180) from the other end.


Super interesting, thanks for typing this all out.


I think the most important thing here is that we stop to think about the gender normativity of the unidentified person's use of the term "guy" in "where's this guy going."

/sarcasm


Those fixed wings people are unflappable.


You monster.


.


There is a very good technical reason we still use AM.

AM is not prone to capture effect, wherein the loudest signal captures the receiver. With AM, you can hear multiple people talking on top of each other at the same time.

https://en.wikipedia.org/wiki/Capture_effect

For uncontrolled radio situations where you have a number of unknown people who need to access a radio channel, neither digital nor encryption bring any wanted benefits.

As a note - the audio from this recording is very clear to me - I've heard far worse out of scratchy narrowband FM.. with AM the weaker the signal generally the quieter it is - but not generally that much noisier.


Yup. FM is great for noise rejection. But any signal which is not "the one true signal" counts as noise. So FM interferes with other FM signals mightily and the most powerful one tends to "win". Whereas with AM the signals just add on top of each other.


-Agreed, intelligibility is pretty good.

I've been into amateur radio for ages, presumably that has trained my ear. I routinely copy voice signals which are just a garbled gibberish to innocent bystanders. (Same obviously goes for ATCs and pilots to an even larger degree, being exposed to comms several hours a day)


Hey There OM :-)

Yeah, Even with P25 - the same skills apply, but instead of pulling it out of noise, you're relying on your skills of interpolation to suck it out of the noise. Still it's a neat parlor trick :-D

73's


Mmm. Here's the thing, I think we heard a lot of the same arguments before DSC took off for marine radio.

They too have uncontrolled radio, a large number of unknown people who need to communicate with whoever happens to be nearby, they have more powerful transmitters owned by governments that "need" to shout down less powerful ones on transport vessels occasionally.

Now, maritime radio IS a different environment. I'm not suggesting that DSC should just be dropped in as a replacement for AM analogue transceivers on planes, but I _am_ saying that I don't buy the theory that it so happens AM analogue is the right choice and not just the result of inertia.


I've used both marine (FM) and airband (AM) radios. My marine experience was in a relatively uncluttered environment (Cleveland) so take this with a grain of salt but I found that you rarely had people talking over each other in that environment, especially with it's limited propagation. Airband on the other hand is almost always a very high radio traffic environment if you are actively switching between tower, departure and center channels throughout the flight. It becomes imperative to be able to tell when someone stepped on ATC and you didn't get some message.


I believe there are significant technical advantages to AM for airband - I also believe that marine radio is less likely to need those advantages, so narrowband digital is more workable there.


they still use AM because higher powered transmitters (which will generally be the tower) can overpower weaker transmitters (planes). i'm given to understand aviation is enamored of that feature.

> Just imagine the economic damage that a single asshole can do with a high-powered transmitter near an airport.

the pilots could probably just pull their cell phones out and call the tower. there is much worse trouble single assholes could get up to.


I'd imagine, as well, that a transmitter powerful enough to drown out a control tower would be very, very difficult to conceal.


I think you'd be very surprised what a lot of power and a shit antenna can do. Obviously won't last when someone comes along with DF equipment, but it really wouldn't be hard to conceal visually.


Visually is the key word here. RF-wise, you may as well put a beacon on the moon and scream "LOOK AT ME" for all the good it'll do when the very, very angry FAA/FCC vans show up.


http://ieeexplore.ieee.org/document/369434

On the other hand, AM is simple and cheap and usable worldwide without significant investment.


Except when said AM transceiver is inside an airplane, then it's thousands of dollars :P


It is a very Silicon Valley thing to assume that everyone else is an idiot and needs to be disrupted, with not a thought given as to why things are the way they are. Sort of funny to watch it from the side

I assure you that there is a reason AM is used. The reason is that in the case that two stations are transmitting, everyone will be aware of it and the stronger signal may be heard. This is not something that FM can guarantee. And a digital protocol requires a much better signal (where old analog tv gave snowy picture digital TV gives nothing). Not to mention the insane costs that digital radio retofitting would require of every single plane in the sky.

Edit: parent seems to have deleted his post. It previously asked condescendingly why we still use AM for comms in the air.


Digital only require better signal if you want high data rates. With analog signal the human has to do the error correction, i.e. extract the signal from the snowy picture. Digital signals can use error correcting codes to get the same result. The more bits you have for error correction, the better your recovery can be.


With a lot of FEC, you can sort of approach it, but still not quite. Human brain is a lot better at picking out voice out of noise than any algorithm currently known. That is , for example, why your Alexa cannot take your commands in the middle of a 100-person party, but your interlocutor can hear you and respond.


That is not very relevant since humans don't use an error correcting code that is easy to understand for machines when talking to each other. So Alexa's ability to filter your voice out of the noise has little to do with the ability of two machines understanding each other over a noisy channel when they use appropriate coding.


I hate aircraft radios. I'm sure the guys in big planes have better equipment and don't suffer from this as much, but when I fly small planes, it's a complete mess of wildly different volume levels (it's fun to turn up the volume to hear a quiet person, then get blasted by the next transmission), interference, and irrelevant transmissions from a hundred miles away. Don't get me wrong, they get the job done and any change would have to be very carefully considered, but I'm always happy when I get far enough from the airport that I can turn the damned thing off.

I think a digital system could be done much better than what we have. But I'm sure it's not worth the huge effort it would take to design and build.


This is a lack of AGC (automatic gain control) - usually even on the (shortwave and Ham) radios I've seen it on, its switchable, otherwise (in certain conditions, like rapid fading) you can end up with gain pumping, which can sound like the audio is surging.

What it normally does is reduce gain on high strength signals, and increases it on weak ones to give a constant volume level.

I'm honestly surprised the radios in general aviation craft are not so equipped, as its generally a standard part of most AM radios.


Thanks, now I know what to look for next time I go equipment shopping. I'm sure many GA radios have this, but I'm using particularly low-end radios since space and power consumption are more important for what I do. Still won't fix getting an earful about skydivers at an airport a hundred miles away, but it would be an improvement!


even KY-97A from decades ago handles this for you


Okay, but do military-grade systems use AM like this too? I imagine their needs aren't any less than those of civilians, and I imagine they've gotten their communication systems to work just fine. So what's the issue?


"Military-grade" systems use complicated techniques like frequency-hopping spread spectrum. They're designed to be encrypted and resistant to jamming. The jamming resistance is not something we care about (if someone is jamming the signal you just make them turn off their radio), and the whole point of encryption is to prevent interoperability when you don't have the right key.

So sure, you could pay a bunch of extra money for military features and end up with a product that is even less what you want than AM radio. And then you'd have to retrofit everything with these systems.

AM is wonderful. You put a bunch of people on the same channel and it just works.


> "Military-grade" systems use complicated techniques like frequency-hopping spread spectrum

Note that that technology has been around since World War II. And fun fact, while we're on that topic, this page is worth a read: https://en.wikipedia.org/wiki/Hedy_Lamarr


I love that a technique that's so widely used now was the co-invented by a movie star. It's also used in cell phones.


"The jamming resistance is not something we care about (if someone is jamming the signal you just make them turn off their radio)"

Evie might know this, too, so I think you should be concerned about jamming. Luckily, AM provides jamming resistance, since Evie would have to bring a powerful transmitter to be loud enough to drown out the other signals.

Nevertheless, I think large airports should have fast response teams who can rapidly fix the position of a jammer and silence it, if needed. If Evie could effectively take out, say, the main airports of LA and SF for a few hours with a few strong AM transmitters, I doubt all will end well.


Evie? I honestly have no idea who that is. But the more powerful the jamming, the easier it is to find the source. These days even hobbyists play around with cheap off-the-shelf RF analyzers and directional antennas, so I can't imagine that someone jamming airport signals would be able to evade arrest for very long.

Heck, the FCC will even track you down if you operate an unlicensed radio station. See: https://www.youtube.com/watch?v=QIGAOLJh-XE


Best guess: user Someone is referring to "Eve" as in "Alice, Bob and Eve" in cryptography scenarios. But Mallory would be more appropriate here.


I don't understand what is so wrong with the transmission quality in that MP3. The issues I hear sound like they are simply due to trying to transmit from an extremely noisy environment (the cockpit of an airplane); they are mitigating the pilot's voice being entirely drowned in the background noise by placing the microphone right next to their mouth, but that then causes the sound of their breath to be extremely noticeable. I am not sure how to fix these issues but they don't seem to have anything to do with the usage of AM radio.


In helicopters/tanks, some people wear a sensor around their neck which picks up vocal cord vibrations without pickup any breathing or external sound.


I wasn't complaining about the transmission quality, I was just trying to understand the parent comment. The person who complained about the former was someone else.


Sorry; I misunderstood (and to be honest even after my tenth reread am still having a difficult time parsing...) the end of your comment about the "issue" :(.


OK, I'll clarify. Someone suggested non-AM transmission has problems X/Y/Z; I suggested that I expect non-AM transmission has overcome problems X/Y/Z in the military, and therefore I'm not convinced this is the real issue preventing non-AM communication. I was not discussing whether we or not we need non-AM communication in the first place.


Airlines don't need military systems which are used more for confidentiality and OPSEC than other things. In the field, militaries tend to avoid radio communications for various tactical reasons. Submarines are a great example of this.


Generally, yes. There are some digital systems used for aircraft to aircraft communications and for a tactical datalink, but yes its AM for landing.


Wow, did not know. Thank you.


Military-grade systems may not be any "less" but their needs and priorities may be different (e.g. secrecy). So different technology may be used, without any contradiction to why the current one is good for civilian air traffic.


> It is a very Silicon Valley thing to assume that everyone else is an idiot and needs to be disrupted, with not a thought given as to why things are the way they are.

This kind of thinking has also lead to a ton of success in Silicon Valley. See Tesla for example.


This kind of thinking led to Juicero.


And applied to aviation you get the Piasecki PA97


Did Tesla really disrupt the car market? Sure, everyone is now building EVs but that already started before Tesla became successful. They have no market power on the overall car market.

Companies like Uber, Google, Amazon certainly disrupted markets but I wouldn't be so sure about Tesla.


Nobody was building long range EVs before Tesla. Short range city cars like the LEAF are really a different category.

Volvo has credited Tesla for pushing car makers into EVs, so at least one incumbent thinks that: https://electrek.co/2017/05/17/volvo-tesla-says-stop-diesel-...

Audi seems to as well, although it's not quite as clear: http://insideevs.com/audis-electromobility-boss-i-hate-to-ad...


>This kind of thinking has also lead to a ton of success in Silicon Valley. See Tesla for example.

Well, not exactly a role model for success. 2016 was the first time they made any profit in all those years -- and its uncertain if 2017 will follow.

And it might still be beaten up in all its markets (electric cars and eventually self-driving ones), not a sure winner yet.


A broken clock is correct at least once a day.


That used to be true (twice a day, even), but now it just flashes 12:00, or the screen is dead.


A clock that flashes 12:00 is still right twice a day.


Unless you live in a country which uses 24-hour clocks, which is most of the world.

Source: https://en.wikipedia.org/wiki/Date_and_time_representation_b...


Do unset clocks flash 12:00 in locations that use 24-hour clocks, or do they flash 00:00?


I can't honestly say I ever paid attention, but I just checked all clocks I could find, one flashes 00:00 and the other 0:00. Most if not all clocks I've used had a 12 or 24-hour mode, not sure what happens if you set to 12-hour and unplug it (probably just reset to defaults).


Flashing is an error condition.


Indeed, a broken modern digital clock is likely to just be blank.


So it's correct at 12 and possibly at midnight too


Here's a night approach on 28R at SFO.[1] Same approach during the day.[2] The taxiway is on the right. It's a straight-in approach over the bay. The runway, like all runways at major airports worldwide, has the standardized lighting that makes it very distinctive at night, including the long line of lights out into the bay. This was in clear conditions. WTF? Looking forward to reading the investigation results.

The planes on the taxiway are facing incoming aircraft as they wait for the turn onto the runway and takeoff. So they saw the Air Canada plane coming right at them. That must have been scary.

[1] https://www.youtube.com/watch?v=rNMtMYUGjnQ [2] https://www.youtube.com/watch?v=mv7_lzFKCSM


> WTF? Looking forward to reading the investigation results.

I'm not an expert, but given what you said, I suppose it'll just end up equating to "Human error. Happens."


I suggest you read ntsb investigations of some major commercial aviation events like this. It is never just "human error. Happens."

They are always full of excellent recommendations, points of failure, etc.


I agree. Check out the NTSB report[1] for the crash into a neighborhood in Queens[2]. 200-odd pages of very sober, rational (and interesting) discussion of how a pilot ended up snapping the vertical stabilizer off an A300. There are many factors leading up to what ends up being summarized as pilot error.

[1] https://www.ntsb.gov/investigations/AccidentReports/Reports/... [2] https://en.wikipedia.org/wiki/American_Airlines_Flight_587


This kind of analysis is aided by the airline industry having very strict training and procedures that flight and ground crew are required to follow, along with regulations that equipment has to comply with.

With them, you can see, for instance, where a pilot or mechanic did not follow procedure, was not trained adequately, or maybe some equipment was out of spec and wasn't caught in a checklist that should have been followed by the maintenance crew, etc.

Compared to the airline industry, most software engineering is much more of a fly by the seat of your pants phenomenon where anything goes, and there's little standardization, process, or regulations that the entire industry has agreed on and actually follows. Such a Wild West approach definitely has a lot of upsides like speed of development, flexibility, freedom to innovate, and so on. But can have a cost in safety, reproduceability, accountability, and analysis of what actually went wrong or how to fix it next time.


The Columbia shuttle accident report is a masterpiece of the genre. It's available at:

http://www.nasa.gov/columbia/home/CAIB_Vol1.html

It's detailed, but well-written and the quality of the analysis is extraordinary.

For a sample, take a glance at the debris maps on page 45, followed up with amazing results on page 75. If you like understated drama, start at the comm transcript on page 42. ("Lock the doors.")


English is not my native language, but shouldn't the headline have read "SFO near miss would have triggered aviation disaster"? "Might" seems to indicate that something else happened afterwards as a possible result of the near miss


I agree.

English is my first language, and the more I read the headline, the more I see it as

"Something terrible happened, and the near miss is possibly the cause".


When I fist saw the headline that's why I went to read it. I wanted to know how a near miss 'possibly caused' the biggest disaster in airline history.

The story was very interesting. The title is technically valid. But as another native speaker I think it's very confusing.


Not a native speaker either (though I've been fluent for decades) and I find the title horribly misleading as well. "Might have triggered" implies the disaster happened, or at least that it's not known whether a disaster happened.

"Would have triggered" implies neither the disaster nor the near-miss happened, so I think the most unambiguous phrasing would have been "could have triggered".

OTOH I've seen native speakers use headlines like "Why this works?" (which by my understanding of the language shouldn't have a question mark), so IDK.


Yes, it's awkward phrasing which implies the near miss led to something else happening.


the problem is that while Could is technically preferable to Might in this situation for exactly this reason, the proper distinguishing between the two conditions has long been vague.

People will often use Could have when they mean might have.

To be accurately and unambiguously understood by everyone it should be SFO near miss could have triggered aviation disaster but didn't. Since the completely unambiguous phrasing is not very elegant then Could have would be preferable, but with the understanding that for some people it will still have some ambiguity that needs resolving by actually reading the article.


"Might" seems to indicate that something else happened afterwards as a possible result of the near miss

In this case it doesn't, the headline can be interpreted in slightly different ways but is not wrong (or really that ambiguous) as written. Standard headline-speak for 'something happened that was a possible cause for something else that also happened' is 'may have caused' like here:

https://www.nytimes.com/2017/06/23/science/bright-nights-noc...


The moral of this story for me is: be that "another pilot." To be clear, "another pilot" of another aircraft. Not as clear as it could be just like the title of this article is ambiguous.

The moral of this story for me is: call out immediately if you see something off. He's the real hero. Even if the ATC controller immediately saw the plane being misaligned at the same time - that feedback confirming another set of eyes on something that is off couldn't have hurt. All 1000 people on the ground needed that feedback. Always speak up in situations like this.


Good observation. If you're wrong, you suffer a brief moment of embarrassment. If you're right, you might prevent a disaster.

Speaking up is a no-brainer.


I don't mean to be a downer, but you could certainly cause an accident by calling out an observation which was faulty. I agree with the sentiment that you should speak up when you see something amiss, but let's not kid ourselves that, like every decision, it comes with inherent risk.


Making an aircraft go-around can never cause an accident - the missed approach path for any landing aircraft is always kept clear.


I wonder how many people have died throughout history due to embarrassment, or (similarly) going against your instinct. The number exists but is unavailable to us.

- Not having that dark mole near your privates checked out.

- Not wanting to turn the car around.

- Not walking away when those shady guys walked in.

...


Korean airlines decades ago had a huge issue with copilots not speaking up to captains when concerned. While not embarrassment - there was a lack of speaking up. IIRC they forced cultural change in order to make it less of an issue.

edit: not speaking up


The moral might also be that automatic guided landing approaches should be mandatory whenever they are available.


And then your Cat-IIIc equipment is offline for whatever reason, and nobody had landed a plane by hand for years at that point. Now what?

(In other words, automation has its own set of failure modes)


Right, but a problem with humans is that they tend to seriously over-estimate their capability. So we need to be statistics led on this

Given the choice between "One time in a million a human flies the aeroplane into the ground and everybody dies" and "One time in 10 million the computer flies the aeroplane into the ground and everybody dies" we ought to be hard-headed and take the ten times fewer deaths, but we prefer to say "Ah, but _my_ pilots are better than average".

Now, the reality gets very complicated, because we ask computers and humans to fly in different conditions. A pilot will refuse to try to land an aeroplane into thick fog, the Cat III ALS is happy to try this because it sees through fog. On the other hand when external circumstances are trying, the pilots may choose not to attempt ALS at all. But despite this complexity, we do need to accept that sometimes a smaller risk of automation error is preferable to the risk of human error even if _neither_ is perfect.


We are not in disagreement. My reply was to "why not automate everything?" and indeed the answer is "because sometimes humans are better," not "do not automate anything" :)


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