Aviation safety margins are so wide that this does not qualify as a near-miss.
I think you have this kind of backwards here. If you were going in for an amputation, and they only prepped the wrong leg, would that not be a near miss?
Rare incidents are hard to reason about and measure because they are so rare; but there are things that lead up to rare events - like being on approach to the wrong runway, that are less rare, and so they are easy to measure.
After you have plans and procedures to stop the actual rare disasters, reducing near misses is the most effective way to stop disasters.
> But no pilot would ever land on a runway (or taxiway) with 3 planes on it.
Oh, full +1. This is a bad incident that should result in an investigation and maybe safety recommendations.
My point is that aviation has been at it for so long, that a "bad incident" is very far removed from what the common interpretation of "near miss could have triggered greatest disaster" (#1 on HN) would suggest to a random observer.
(And I think the author knew it, and went for clickbait.)
We know from the recording that the pilot saw planes on the taxiway and asked the tower about it. He would've never landed there after the tower confirmed that the runway should be empty.
Safety margins are wide when pilots don't screw up. But this one did. Royally.
And the safety margin was wide enough to absorb that screw up.
This is _why_ we have wide safety margins. So that one screw up doesn't absorb all of it. People will always screw up, and policy accounts for that fact.
Barely.
For example, the approach controller may have noticed that a plane they recently handed off to Tower was not yet lined up. The controller would then call up to Tower to make Tower aware of the issue.
Or, Tower may have a screen showing them a radar view of the approach, similar to Approach's screen. They may have noticed it there.
But, the nature of aviation radio is such that you use one frequency to transmit and receive. That means you can't speak over anyone else; you have to wait for them to stop talking before you can start. And if you mess up, there's no easy way for you to know (except when someone else on frequency says "blocked").
* Conditions were clear. The pilot landing would have an increasing probability of noticing their mistake from lights on the runway and taxiway as they got closer to landing.
* After being alerted that the pilot landing could see lights on what they thought was the runway, the ATC would likely have paid closer attention to the various tools available to them to see the location and heading of the aircraft.
And finally, the one factor that happened to be the first of these to happen:
* Multiple pilots looking directly toward the oncoming aircraft, one of whom alerted ATC.
Just because this happened first doesn't mean the other things failed or wouldn't have happened.
> * Multiple pilots looking directly toward the oncoming aircraft, one of whom alerted ATC.
I don't get this.
You're an engineer/pilot/whomever filing for {the current system/pilot/plane/whatever-needs-approval} to get approved. The power-that-be (e.g. FAA) asks you what your safety margins are. You cite "other pilots looking directly at my aircraft in the 30-second span of my mistake" as one of your "safety margins"? ...what?
Incidentally, Aviation Herald reports[1] that "AC-759 had already overflown taxiway C by about 0.25nm when ATC instructed the aircraft to go around" and further that "it is estimated that AC-759 overflew the first two aircraft by 100 feet".
100 feet isn't much, and I imagine this was utterly terrifying for the pilots lined up on the taxiway, but 0.25nm past the beginning of taxiway C is basically touchdown point on the runway (had they been lined up with it), and they were still 100 feet above the ground. That indicates pretty strongly that the pilot of AC-759 had noticed their mistake and was taking evasive action already, before ATC instructed them to go around.
Notwithstanding the timing on the tape, the AC jet could not have been very far away because the fact that he was lined up with the taxiway was first noted by a plane on the ground. That would not have been evident unless the plane was very close.
http://archive-server.liveatc.net/ksfo/KSFO-Twr2-Jul-08-2017...
The action starts at about 14:45. I suspect there isn't much silence removed in this particular area, so 40 seconds may be close to the actual time.
I haven't been able to find a pure unedited version. They may not be saved.
Just like no pilot would ever crash into the seawall short of 28L in broad daylight with unlimited visibility. In that case the pilots knew what was about to happen seconds before impact and they were powerless to stop it. I could easily see the same thing happening here. Airplanes are big cumbersome objects with a ton of inertia.
Though air traffic was not heavy at Los Angeles airport, the local controller was distracted as Flight 1493 was on final approach by a series of abnormalities, including an aircraft that inadvertently switched off the tower frequency and a misplaced flight progress strip, which resulted in the SkyWest flight being told to taxi into takeoff position while the USAir flight was landing on the same runway without the Metroliner ever being given a takeoff clearance.
Upon landing, the 737 collided with the twin-engine turboprop, continued down the runway with the turboprop crushed beneath it, exited the runway, and caught fire. All 12 people aboard the smaller plane were killed, as well as an eventual total of 23 out of the 89 passengers on the Boeing.
Based on that, it was seconds away from a collision. It seems like a near miss when considering aviation safety margins.
So the pilot probably did not start the go around before being told so.
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/...
But you're right, the pilot may have started the go around but we can't tell what happened from the footage.
This is more like runway "confusion". A term I made up, not sure if there is such an official name for it.
This is why you want human pilots, instead of computers, not the opposite. A human can apply common sense and decide not to land on three planes after all even if it looks like a cleared runway.
I actually believe the opposite is true. Systems like ACARS have managed to avoid the prevalence of air to air incidents that used to be almost an epidemic in the 60's and 70's.
Autolanding technology has brought planes home safely where a pilot would have had to go around and find an alternate aerodrome.
(ACARS is used for delivering clearances and other routine operational/maintenance messages. Basically text messaging for airplanes.)
In theory yes, but the risk is that the plane you crash into is not yet on the taxiway or that poor visibility or tunneled focus prevents you from noticing it.
You don't need to be moving quickly to have a significant accident. The deadliest aviation accident in history (583 fatalities) resulted when two planes collided on a taxiway (edit: actually on the runway) in dense fog [1].
Edit: as correctly pointed out below, the actual collision took place on the runway at significant speed.
Which seems to be what happened here - the pilot aligned with the taxiway, noticed he was in the wrong spot, and the tower told him to try again.
LOTS of planes accidentally line up on the taxiway if visibility is reduced and cockpit workload is high. Heck, aircraft have even taken off on non active runways at the most advanced airport in the world with disastrous results at night. [0]
Inclement weather on approach at the end of a long flight can also lead to crew pressing home while under confusion, as in the case of the Korean airlines accident that landed short. [1]
More recently, at SFO too, the Asiana B777 crash was something that should have been almost impossible in a modern jetlines, but over reliance on automation and lazy piloting lead to that disaster.
Fundamentally it takes several things to fail all at once for an air disaster to actually transpire, but it does happen.
There is a pprune forum post of an american instructor explaining how a visual circuit flown in manual was the worst "emergency" he could set in a simulator. Up to the point that he failed one of the chef pilots in Asiana and they wanted to fire him. This seems to be a cultural thing, they ace the theory (really know all the manuals by heart), but are not allowed to think outside the box at all.
This airmiss is important, but could only happen flying in manual and visual conditions.
It's hard to ignore the sigthing of other planes in that conditions, even if you are confused about which strip you are aligned with.
In my opinion it's much more dangerous taxing in a complex airport with fog. There is a real problem of runway incursions, that could be solved with better systems.
I'll try to find the pprune post.
The pilot here was flying visually (which I expect either means a visual approach, or else the LDA PRM Runway 28 Right approach).
If the airport was fogged out, the pilot would be on an ILS or RNAV (area navigation) approach. The former uses ground-based signals to provide precise lateral and vertical navigation; the latter uses either GPS or multiple ground-based aids to accomplish the same thing.
The downside to ILS, RNAV, etc., is that you can't fit planes as close together while still being safe. That's why you get delays when major airports have reduced visibility: The flight scheduled are "tuned" for maximum planes per runway per minute, which is only possible when skies are clear and winds are (relatively) calm, so that you can use visual approaches.