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Comment by jcdavis | Hacker News Reader

ATC audio from the crash http://wandr.me/Audio/AAR214-KSFO-Crash.mp3

I know they train for it, but the coolheaded professionalism there is remarkable - tower, other planes, all of them.

Agreed. It was like it didn't even phase the controller. Wow.

That's why airlines like to get pilots with military experience. They are exposed to more crazy scenarios in training and work and generally keep a cool head better under stress.

Hmmm - but: military pilots are also known (especially in some cultures) for an over-strong respect for hierarchy, resulting in a willingness to go along with dangerous instructions. Also, at least some military pilots are trained to have a higher risk acceptance than civilian pilots.

Personally, I'd be very happy having an ex-military pilot flying me around; I think the pros definitely outweigh the cons. But do be aware that the cons exist.

> Hmmm - but: military pilots are also known (especially in some cultures) for an over-strong respect for hierarchy, resulting in a willingness to go along with dangerous instructions. Also, at least some military pilots are trained to have a higher risk acceptance than civilian pilots.

Can you elaborate more on what how dangerous instructions would work in a civilian scenario? Where does a hierarchy come into the picture?

Person A, in authority but missing a critical piece of information (e.g. senior pilot who mistakenly believes airspeed is high when the plane is nearly stalling) gives disastrous instruction (pull up) to person B (co-pilot) who has the crucial information, but obeys rather than contradicting A, due to hierarchy.

Actually Korean pilots (civilian) are also known to have too strong a respect for hierarchy. I remember seeing an episode of air crash investigating where that was officially reported as a factor, so it isn't even just the military where that can be a risk.

This is the most famous incident, and the one that lead to the development of Crew Resource Management, a process to make sure decisions are taken by consensus, not by deferring to authority. The crew in question, by the way, was dutch.

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

ATC operators must be the most underrated people in our transportation system.

Underrated by who? Society? What's the most highly rated profession in transportation?

Maybe unappreciated is a better choice of words. Overrated would be taxi drivers and municipal taxi regulators.

Is there a transcript available?

I transcribed part of it:

0:00-0:02 - Tower: "Asiana 214, San Francisco Tower, runway 28 left, cleared to land"

0:02-0:04 - Asiana 214 pilot: "Cleared to land left, Asiana 214"

0:05-0:08 - Tower: "Skywest 5427, fly runway heading and contact (north cal?) departure" (plane took off and is making a straight-out departure, and now will contact departure control)

0:09-0:12 - Skywest 5427 pilot: "OK, going to departure, Skywest 5427 (free?)"

0:12-0:14 United 885 pilot: "United 885" (pilot makes a quick break call to tower before making a longer request)

0:14-0:16 Tower: "United, uh, 85, OK?" (tells pilot to go ahead)

0:17-0:21 United 885 pilot: "Yes, United 885 at the end, we might need a few more minutes, just a heads-up" (It sounds like 885 is next for takeoff and has taxied into position next to the runway)

0:21-0:25 Tower: "United 885, roger, hold short of runway 28 left, let me know when you're ready"

0:25-0:27 United 885 pilot: "Hold at 28 left, United 885"

0:27-0:32 Skywest 5452 pilot: "San Francisco Tower, Skywest 5452, (quite ?), 28 right"

0:32-0:36 Tower: "Skywest 5452, San Francisco Tower, runway 28 right, cleared to land"

0:36-0:38 Skywest 5452 pilot: "Clear to land, 28 right, Skywest 5452"

0:38-0:41 Tower: "Three Sierra Fox... (garbled)"

0:39-0:41 Voice in background (in tower?) "What? Hell? What happened?"

0:43-0:50 Skyhawk 737ZD pilot: "San Francisco Tower, Skyhawk seven three seven zulu delta (garbled, another transmission saying 'GO AROUND') (something) plus 500 feet please, over San Carlos" (A four seat Cessna is over the San Carlos airport just southeast of SFO and wants to cross the SFO airspace. 737ZD [if I have it right] is the aircraft's tail number, no connection to the Boeing 737.)

0:50-0:52 Tower: "Skyhawk 6389, maintain 3000 [feet altitude]" (It sounds like 6389 is on approach to land and tower is telling him to go around? Not sure)

0:53-0:54 Skyhawk 6389 pilot: "(something) 3000, yes, 389" (speaking quickly to keep the channel clear)

0:55-0:57 Asiana 214 pilot (!!): "Tower, Asiana 214!"

0:57-1:00 Tower: "Asiana 214 heavy, emergency vehicles are responding" ("heavy" refers to any large aircraft)

1:00-1:01 Asiana 214 pilot: "214" (acknowledging)

1:02-1:03 Tower? "Emergency veh(something)"

1:03-1:09 Asiana 214 pilot: "OK, now, uh, uh, and ten or twelve (?) (unintelligible)"

1:10-1:16 Tower: "Cessna 737 Zulu Delta, San Francisco Tower, remain clear of the San Francisco (Fox Bravo?) airspace, contact San Carlos Tower"

1:17-1:21 Skyhawk 737ZD pilot: "Seven Zulu Delta, contacting San Carlos Tower, and remaining clear"

There's another minute or so on the recording, but my nerves are shot after doing that much. If anyone would like to pick it up from there, correct it, etc., please do.

Thank you. Amazing job. Was hard to understand the audio.

Yeah, I have listened in on some air traffic controller streams that are available online and it's always hard to decipher what it is they are saying. It all sounds like words slurred together with no clear demarcation. I am mostly amazed how pilots and the controllers clearly understand each speaking the way they do.

Also, kudos to the tower. It is seriously an amazing thing they do, and to stay cool and calm and efficient all during a crash, to keep the rest of the traffic clear and headed in the right direction.

It's part learned jargon and part ritual... also (though I don't know) probably easier to hear in a headset than on a low bitrate mp3 recording.

The engineering term to google is data redundancy with a bit of communication theory and stuff like that.

0:32-0:36 Tower: "Skywest 5452, San Francisco Tower, runway 28 right, cleared to land"

0:36-0:38 Skywest 5452 pilot: "Clear to land, 28 right, Skywest 5452"

This looks like 6 seconds of jargon containing about 25 words, but it really only contains one single bit of information that being that in the giant state machine of flowchart of flying a plane, everyone mutually agrees its your turn to click forward precisely one step. Once you look at it that way, the "conceptual bit rate" drops dramatically lower. 5452 probably expected to get 28R all along, and based on where he was probably expected to get clearance "right about then" too.

"Hey you, its me, you can land over there"

"Hey you, its me, I think heard you say I can land over there" (with the implied, if I misheard, you'd best start yelling right about now either at me or at everyone else to get out of my way)

When its just business as usual, things click along awful fast. When ATC gives out some "unpredictable" order or a pilot has a weird request, there's always a very dramatic pause due to cognitive load. I can have my scanner monitoring the local tower for fun and Very quickly you learn to tune out BAU chatter until/unless weird tempo strikes. You can also tell purely by cadence and tempo with near perfect accuracy if the pilot is a local or a noob in general or a distant traveler.

I did my best.

1:10 ATC: 737 Zulu Delta San Francisco Tower, remain clear of the San Francisco Fox Bravo airspace [ed: I believe Bravo refers to the SF Class B airspace, not sure what the Fox is]. Contact San Carlos Tower

1:17 737 Zulu Delta Pilot: Contacting San Carlos Tower and remaining clear.

1:22 ATC: 305 start leaving the Bravo airspace and 2 miles .. terminate ... maintain the appropriate stage ..

1:27 ATC: (inaudible) is closed San Francisco Tower (inaudible)

(inaudible command to Horizon 635 from ATC)

1:34 ATC: He's got a 214 heavy, San Francisco Tower

1:37 ATC: Asiana (inaudible)

1:42 635 Pilot: 635 going around.

143 ATC: 635 fly heading 2-6-5 maintain 3100 (ft).

1:46 635 Pilot: 265 3100 - alright 635.

Asiana (inaudible)

1:51 ATC: Asiana 214 heavy emergency vehicles are responding, we have everyone on their way

1:57 ATC: SkyWest 5452 san francisco tower go around

2:00 SkyWest 5452: Go around Skywards 5452

2:03 ATC: SkyWest 5452 fly heading 2-8-0 maintain 3000 ft.

2:07 SkyWest 5452 Pilot: 280 and 3000, SkyWest 5452.

2:10 Horizon 635 fly heading 2-6-5 maintain 3100

2:13 635 Pilot: Yes sir 265 3100, Horizon 635

2:16 ATC: Contact NORCAL reports for 135.1

2:19 635 Pilot: 35.1 - Horizon 635

2:22 SkyWest 5452 contact NORCAL reports for 135.1

2:25 5452 Pilot: 35.1

2:27 6039 Pilot: 6039 will go to San Jose

2:31 ATC: SkyWest 6039 roger. Contact NORCAL for departure

2:35 ATC: (inaudible) SkyWest 6389

2:39 ATC: rescue 33 San Francisco tower proceed to the scene cross - inaudible - the 11 San Francisco Tower proceed as requested. Cross all runways.

2:46 Rescue: San Francisco Tower 33 and rescue 11 cleared the 1.

2:50 ATC: rescue 33, rescue 11 roger.

2:54 ATC: (inaudible) Foxtrot San Francisco Tower

END.

I also listened to the ATC before descent, no talk about any failures or problems or requests for rescue before descent.

Edit: I was transcribing this when you were, apparently; but here's mine, in case we caught different things.

1:23 Tower: tells a departing helicopter to depart 2 mi straight out, turn right, squawk a certain signifier on its altimeter (standard practice), and approves a frequency change (also standard practice);

1:28 Tower: cuts out briefly and then says "..is closed, San Francisco Tower."

1:31 Tower: silence, then starts to tell a Horizon flight something and the Asiana pilot cuts in with [hard to hear, best guess]"San Francisco?" Also, Sounds to me like they put Asiana 214 on a priority channel over other flight traffic, or that the tower cut itself/other pilots off when they saw/heard Asiana 214 was speaking.

1:36 Tower: Asiana 214 Heavy, San Francisco Tower

1:37 Asiana 214: [unintelligible, but my best guess: This, uh..., how much is this, uh, where is, uh,... uh,..."]

1:42 Horizon 635: 635 is going around

1:43 Tower: Horizon 635, fly heading 265, maintain 3100

1:46 Horizon 635: 265, 3100, Horizon 635

1:49: Asiana 214 [garbled]: San Francisco?

1:52 Tower: Asiana 214 Heavy, emergency vehicles are responding; they have everyone on their way.

1:56 Asiana 214: [garbled, definitely a few words and then a static burst]

1:58 Tower: Skywest 5452, San Francisco Tower, go around.

2:00 Skywest 5452: Go around, Skywest 5452

2:30 Tower: Skywest 5452, fly heading 280, maintain 3000.

2:07 Skywest 5452: 280 at 3000, Skywest 5452

2:10 Tower: Horizon 635, fly heading 265, maintain 3100.

2:14 Horizon 635: Yessir, 265, 3100, Horizon 635.

2:17 Tower: Contract North Cal departure 135.1.

2:19 Horizon 635: 35.1, Horizon 635.

2:22 Tower: Skywest 5452, contact North Cal departure 135.1.

2:26 Skywest 5452: 35 1.

2:28 Skywest 6389: 6389 We'll go to San Jose.

2:30 Tower: Skywest 6389, Roger. And, uh, contact North Cal departure.

2:34 Skywest 6389 [garbled]: What's the... frequency for that?

2:36 Tower [garbled at start]: [garbled] point 1, Skywest 6389.

2:39 Tower [garbled at start]: Rescue three three, San Francisco Tower, proceed to the scene, cross runway; [garbled, maybe "Rescue"] eleven, San Francisco Tower, proceed as requested, cross all [garbled, "runways"?]

2:46 Rescue 11: San Francisco Tower, [garbled, maybe "Rescue 33"] and Rescue 11, cleared to one.

2:50 Tower: Rescue 33, Rescue 11, roger.

2:54 Tower: [garbled] Foxtrot, San Francisco Tower

[end transcript]

Apparently I was doing this simultaneously with you; oops.

Your "6039" should be "6389". It was only clearly audible the last time on the tape, the previous couple times it did sound like 6039 due to interference.

The "Fox Bravo" is actually "Class Bravo", and you're right, it's a reference to the SFO Class B airspace. I can't edit my comment any more or I would fix it there...

Any idea what stage of landing 214 was at when mention emergency vehicles? Had it hit the ground?

>Had it hit the ground?

Yes, that was post-crash.

Some more insight regarding the ATC audio: http://www.liveatc.net/forums/atcaviation-audio-clips/asiana...

Amazing. Wish I understood what's happening in each exchange.

Basically, the United flight holds short of runway 28 as he may need a little more time (this is the United flight CNN showed sitting there, probably).

The ATC controller knows something has happened because the first time we hear from 214 heavy, the controller tells the pilot emergency vehicles are on the way.

Then some captains on final announce they're going around and some ask for redirect (one clearly to San Jose). The controller then tells some flights on final to go around.

Finally he's directing rescue units to cross all runways where normally they'd hold at each runway to be directed.

I found these comments helpful. They breakdown the exchange between the tower and the approaching planes. The first is from an air traffic controller.

http://www.reddit.com/r/worldnews/comments/1hrewx/asiana_air...

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