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SFO near miss might have triggered aviation disaster

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Re: SFO near miss might have triggered aviation disaster

#141

Post by dheera »

cyberferret wrote: post #33
wfunction wrote: post #21

Earlier quoted context omitted.

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…

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.

Re: SFO near miss might have triggered aviation disaster

#142

Post by konschubert »

dx034 wrote: post #128
dbroockman wrote: post #36

Earlier quoted context omitted.

Seems like disaster was only avoided because there was good visibility. If there was fog that day, it sounds like this wouldn't have been avoided.

In a foggy situation they would've used ILS or even autoland. Looking at instruments instead of out of the window would've prevented this much earlier.

If ILS and autoload can prevent this, why is it not mandatory?

Re: SFO near miss might have triggered aviation disaster

#143

Post by kakwa_ »

cyberferret wrote: post #45
willidiots wrote: post #38

Earlier quoted context omitted.

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 refr…

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

Re: SFO near miss might have triggered aviation disaster

#144

Post by Animats »

rdtsc wrote: post #13

Without knowing the cause but if I had to guess this looks like pilot error. At least statistically that the leading cause of crashes. I am surprised pilots still manually land planes. Is the auto-landing feature not implemented well enough? But then it's relied upon in low visibility. So it has to work, they why isn't it used more often?

Too soon to tell what the problem was. Possibly there was some other problem in the aircraft that was taking some pilot attention. Give this some time.

Re: SFO near miss might have triggered aviation disaster

#145

Post by cyberferret »

wfunction wrote: post #104
cyberferret wrote: post #80

Earlier quoted context omitted.

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…

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.

Re: SFO near miss might have triggered aviation disaster

#146

Post by sohkamyung »

ddeck wrote: post #14

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 Seattl…

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

Re: SFO near miss might have triggered aviation disaster

#147

Post by InclinedPlane »

Aloha wrote: post #70
desdiv wrote: post #43

Earlier quoted context omitted.

.

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 a…

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.

Re: SFO near miss might have triggered aviation disaster

#148

Post by idlewords »

dheera wrote: post #141
cyberferret wrote: post #33

Earlier quoted context omitted.

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…

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.

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...

Re: SFO near miss might have triggered aviation disaster

#149

Post by CaliforniaKarl »

exDM69 wrote: post #135
CaliforniaKarl wrote: post #129

Earlier quoted context omitted.

What's missing is, when (relative to radio traffic) did the pilot begin the go-around maneuver. Did they begin doing so before being told to go around, or did they only start to do so after?

If the pilot initiates a go around they need to announce it to the ATC. It is usually a drastic full power pull up that will certainly disrupt nearby air traffic. So the pilot probably did not start the go around before being told so.

Sorry, I have to partially disagree. The FAA is pretty clear on this: The priorities (in order) are Aviate, Navigate, and Communicate[1].

The pilot is ultimately the person responsible for the safe operation of the aircraft. That will occasionally mean performing a maneuver before telling anyone.

In response to this, procedures are designed so that pilots can safely abort an approach without posing a danger to themselves (i.e. running into terrain) or other aircraft.

For example, let's look at the LDA PRM runway 28 Right approach [2] into SFO, which the pilot may have been flying. If you have to abort the approach prior to the DARNE waypoint, you make a climbing right turn to heading 030 and 3000 feet, then you proceed directly to the Oakland VOR, and then you hold as published.

When Approach clears you for this approach, the controller is also clearing you to fly the missed approach, if needed.

If you have to go missed-approach after DARNE, the instructions are similar, but are documented in [3] instead of in [2]. But note the "unless otherwise instructed by ATC". In this case (see [4]), Tower placed the pilot onto runway heading, likely with a climb to avoid the hills. Approach would then have taken over, and brought the pilot back around.

[1]: https://www.faasafety.gov/gslac/ALC/course_content.aspx?cID=...

[2]: http://155.178.201.160/d-tpp/1707/00375LDAPRM28R.PDF

[3]: http://155.178.201.160/d-tpp/1707/00375PRMAAUP.PDF

[4]: https://flightaware.com/live/flight/ACA759/history/20170708/...

Re: SFO near miss might have triggered aviation disaster

#150

Post by InclinedPlane »

blhack wrote: post #34

People "could" run their cars off of bridges every day, but they don't because they can see, and because roads have signs warning them of curves. This sounds like a story of how well the aviation system works more than anything. The pilot is in constant communication with the tower. The system worked as intended here and he went around. It seems like a non story.

The pilot not only had his plane headed "over a cliff" (lined up to land on the taxiway), he would have done so had nobody else caught the error. Causing massive loss of life in the process. This is officially a capital-P Problem.
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