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Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

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Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#21

Post by 7952 »

gok wrote: post #4

It's kind of baffling to me that there's a system for detecting collisions with other airplanes in the sky (TCAS) and a system for detecting collisions with the ground (EGPWS) but not system for detecting collisions with other airplanes on the ground. This easily could have killed a thousand people.

I think this is really just a case of flying into the ground. It just happened to be in close proximity to other aircraft. There are lots of systems that are available to avoid that (ILS, GPS etc.) which were not used in this instance. And a system for avoiding collisions for taxing aircraft is probably not much use at such high speeds.

Some airports do have a system [0] designed to track taxing aircraft and allow collision risks to be detected.

https://en.wikipedia.org/wiki/ASDE-X

Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#22

Post by sokoloff »

tialaramex wrote: post #15

CVR overwrite is bad news here. The crew knew this was a serious problem when it happened, there's no way they should have allowed the CVR, crucial evidence of exactly what happened, to be overwritten. Perhaps the full report will have more detail on this, as it stands I have to believe somebody made the decision to overwrite this because they thought it'd be better if it didn't exist. Whether that's the crew, their…

Subject aircraft, C-FKCK, is a 1991 A320, which is only required to have a 30 minute CVR loop. (I don't know which exact CVR it was equipped with, of course.)

By the time the aircraft goes around, is resequenced, completes the second approach, lands, taxis in, and shuts down, much of the initial approach setup conversation may have already been overwritten anyway. I wouldn't jump to the assumption that there was malicious intent in the fact that the CVR was overwritten. (I also wouldn't want the crew to stop the CVR recording only to have a second, more serious incident on the same flight that would then go unrecorded.)

Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#23

Post by zkms »

aeternus wrote: post #12

I'm surprised that remote video cameras aren't used by tower controllers. The perspective of the control tower makes it difficult to catch issues like this, but a simple video camera aligned with the center-line of each runway would allow controllers to more easily verify that planes are lined up as well as other possible issues like gear down & locked, etc.

> I'm surprised that remote video cameras aren't used by tower controllers.

I'm surprised that forward-looking infrared cameras aren't more commonly used in civilian aircraft, especially given the availability of staring arrays with decent resolution/framerate that don't require cooling.

Even without the requisite certification for use as a for-realsies landing aid, it's nevertheless a useful tool to get situational awareness in inclement weather / at night.

Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#24

Post by abaillargeon »

I've been anticipating the release of this report this since I heard about the incident.

I work on an avionics product that's designed to prevent this exact scenario. We use the aircraft's position along with a database of runways and taxiways to determine if the aircraft is approaching the runway the pilot intends. If we determine the aircraft is landing, we issue a visual and aural alert to the pilot ("TAXIWAY LANDING" or "NOT A RUNWAY").

Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#25

Post by sokoloff »

throwaway5250 wrote: post #14
cmurf wrote: post #5

I'm not operationally familiar with SFO. But based on experience at other airports, a taxiway at night can be a sea of black at even 100' above the ground. I would probably see airplane navigation lights at some point, but would I bet my life on it? No. So this incident has to be taken seriously. However, I'm still not clear from this reporting how the crew mistook blue taxiway lighting for white runway lighting. Thi…

I give up--why shouldn't airplane strobes be on while they're on the ground?

Harms night vision adaptation of other pilots.

My SOP is beacon (red, top and bottom) on with aircraft battery bus on, strobes on only when on an open runway, landing lights on when cleared for takeoff (or lined-up and waiting in position for takeoff). That seems to be a fairly common SOP for aircraft with separate control of beacon vs strobe.

It communicates a small amount of additional information, but more relevantly, it doesn't leave you sitting next to another airplane with blinding strobes on, killing your night vision adaptation. (Cirrus drives me crazy with their single switch anti-collision lights which light the strobes and beacon together.)

Here's the FAA (recommended, but not regulatory) guidance on the topic: (See "Use of Aircraft Lights") http://www.faraim.org/aim/aim-4-03-14-209.html

Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#27

Post by cpitVoxRec »

tialaramex wrote: post #15

CVR overwrite is bad news here. The crew knew this was a serious problem when it happened, there's no way they should have allowed the CVR, crucial evidence of exactly what happened, to be overwritten. Perhaps the full report will have more detail on this, as it stands I have to believe somebody made the decision to overwrite this because they thought it'd be better if it didn't exist. Whether that's the crew, their…

They actually do clearly state in this PDF that a degree of fault lies in the crew being compromised by fatigue. Operating for 19 hours straight definitely places an individual in an area where one can be fighting to pay strict attention, even when it really counts.

There's also plenty of communication with Air Traffic Control in the tower, and not a whole lot of gaps to introduce significant mystery, so it's pretty unlikely that there would be anything earth shattering on the cockpit voice recorder.

Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#28

Post by walrus01 »

aeternus wrote: post #12

I'm surprised that remote video cameras aren't used by tower controllers. The perspective of the control tower makes it difficult to catch issues like this, but a simple video camera aligned with the center-line of each runway would allow controllers to more easily verify that planes are lined up as well as other possible issues like gear down & locked, etc.

> I'm surprised that remote video cameras aren't used by tower controllers.

There are software and hardware/network setups designed to do this now, in fact London City Airport is about to move to a fully virtual control tower, with a bunch of super high res pan/tilt/zoom cameras on a mast instead of an on-site tower.

https://www.google.com/search?client=ubuntu&channel=fs&q=lon...

Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#29

Post by drcoopster »

throwaway5250 wrote: post #14
cmurf wrote: post #5

I'm not operationally familiar with SFO. But based on experience at other airports, a taxiway at night can be a sea of black at even 100' above the ground. I would probably see airplane navigation lights at some point, but would I bet my life on it? No. So this incident has to be taken seriously. However, I'm still not clear from this reporting how the crew mistook blue taxiway lighting for white runway lighting. Thi…

I give up--why shouldn't airplane strobes be on while they're on the ground?

They ruin other pilots' and crewmembers night vision.

Sokoloff's post just before mine is more articulate on this. I learned the same: strobes on when cleared for takeoff.

Re: Abstract of the NTSB Report on Air Canada flight 759's taxiway overflight at SFO [pdf]

#30

Post by sokoloff »

8_hours_ago wrote: post #16
SaberTail wrote: post #13

If anyone would like to listen to the ATC radio: https://www.youtube.com/watch?v=ZW-ETmZU0u8

I was just about to post that link! VASAviation has a really good youtube channel with ATC radio recordings and high quality visualizations of all kinds of interesting events: https://www.youtube.com/user/victor981994

https://www.youtube.com/watch?time_continue=57&v=oF7FR7TjnME has an overview shot, showing just how low AC759 got to the airplanes on Taxiway C. (Look at the top of the frame.)
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