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‘Confirming we are cleared to land?’ Who said what at Austin

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Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#221

Post by michaelmrose »

kcg wrote: post #89
michaelmrose wrote: post #52

Earlier quoted context omitted.

Who is saying that procedures allow one plane to take off when one is "3 miles out" or 65 seconds out at a very conservative estimate of a reasonable speed. This isn't a lack of attention or coordination. He literally decided that one plane could take off in that space and repeatedly confirmed this decision.

> Who is saying that procedures allow one plane to take off when one is "3 miles out" The FAA says that, specifically the 7110.65 which governs ATC rules and procedures. In a radar environment it allows for departures when the arriving aircraft is 2+ miles from the runway, and there will be at least 3 miles of separation within 1 min of takeoff. A separate rule requires that the departing aircraft is at least 6000ft…

It says there can be as little as 2 miles of separation which I read as 2 miles when the wheels lift off begining acceleration would end up with 0 ft of separation.

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#222

Post by [deleted] »

reisse wrote: post #207
harshreality wrote: post #194

Earlier quoted context omitted.

It was a good thing to try, but the Southwest plane was above V1 (edit: may not have been, but acted as if they were) and couldn't abort, and didn't. Both planes climbed away from the runway with minimal clearance between them. It was simply luck that they didn't crash anyway. The fast reaction by the Fedex pilots may have contributed to increased distance between the planes that saved them, but their callout to the…

> Southwest plane was above V0 and couldn't abort It's up to investigators to find out. Pilots definitely can (and have the right to) abort after V1, if they consider it safer than taking off. Before V1, you can be sure that abort is safe, after V1, you have to weigh risks of high-speed abort against risks of continuing flying, but staying on the ground is still possible. Yes, and nitpicking - decision speed is V1, n…

[deleted]

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#223

Post by mcv »

0xFF0123 wrote: post #199
mulmen wrote: post #187

Earlier quoted context omitted.

Europe uses pessimistic runway locks but the US prefers optimistic locks. This improves throughput at US airports with the risk of a rollback on a dirty runway.

I'd be curious to know how much it actually improves throughput. It seems strange to use optimistic locks in such a safety critical process, when a more fail-safe approach is available.

Sounds like a money problem to me. Less time between planes means more planes means more money.

It sounds to me like far too many critical safety decisions are being made with an eye on money rather than safety. There were reports warning that Fukushima wasn't safe in case of a tsunami, but the company in charge of the plant decided to ignore that. Deep Water was caused by cost cuts. The Boeing 737 Max was made for financial reasons, fixing a fundamental hardware problem in software.

Safety engineers clearly need a bigger say in these things.

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#224

Post by jnsaff2 »

cjrp wrote: post #217
jnsaff2 wrote: post #165

I got my PPL in EU and here it was drilled into me that in Europe there can be exactly ONE plane cleared to use a runway at any time. When the approaching plane is cleared then there is no allowance for anyone and anything to be on the runway. So if there is a departing plane waiting on the runway or someone crossing then the approaching plane is given "cleared approach runway 08" but never "cleared to land". Which a…

It seems that the US also has different rules about Low Visibility Procedures / protection of the ILS sensitive area; I don't believe you'd clear anyone for takeoff with someone on a 2-3 mile final, under LVPs.

Yes, this!

In Europe, I have heard, you can't operate CAT III ILS (or even maybe CAT II) when your ground radar is inop.

It seems that in Austin they don't even have a ground radar. How the hell is CAT III a thing there?

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#225

Post by TrickyRick »

AdamN wrote: post #190
_cenw wrote: post #179

Earlier quoted context omitted.

In 2020, ATC directed an incoming United 787 on the wrong runway at Paris-Charles de Gaulle Airport. The only reason nothing terrible happened is that the Easyjet pilot on the wrong runway called for go-around after looking out the window, moments before the would-be collision. Didn't make it beyond aviation news, probably because recording ATC is not allowed in France. Human error will creep up everywhere, all you c…

ATC cannot be recorded? Where else is that the case?

In the UK it's not only illegal to record, it's also illegal to even listen. https://aviation.stackexchange.com/a/3280

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#226

Post by account42 »

hef19898 wrote: post #97
bagels wrote: post #90

Earlier quoted context omitted.

Time 1:54, Tower: “Southwest 708, confirm on the roll?” They don't know if Southwest was moving?

ATC is run by humans, planes are piloted by humans. The whole environment is highly controlled and regulated. And highly complex, and as this incident shows, one mistake in the whole chain, even a little one, can literally kill hundreds of people. This is nothing one can solve by throwing even more sensors and technology in, and have that run by ChatGPT or something. Highly trained people with the right amount and ki…

That humans are in charge of ATC and flying the planes doesn't mean that there can't be automation to assist them and cover mistakes.

Poor visibility should not ever be a factor when we can have sensors that show exactly where the plane is on the ground. And yes we are definitely at a point where machine learning can predict the likely actions based on the human communication and warn if the predicted path could lead to a collision. The point is to have multiple safty systems (inclduing the human operators) so that one mistake doesn't kill hundreds of people because there are secondary systems to catch it.

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#227

Post by Xcelerate »

hef19898 wrote: post #175
nenad wrote: post #167

Earlier quoted context omitted.

> If you are not involved directly with any of that professionally, it is better to treat it the way non-developer treat the OS. Assume it will work as intended because loads of highly trained professionals take care of it. Added benefit ehen it comes to aviation: strict and sensible regulation (the MAX disaster notwithstanding). Allow me to chime in and respectfully disagree with this sentiment and the metaphor. As…

And what makes anybody think this incident will not be properly reviewed, analyzed and suitable mitigation actions identified? And why do people on HN always think they know it better than the actual experts in this field, while just expectung users of their products, I just asse in most cases that is some piece of software, to worry about the details at all?

> And why do people on HN always think they know it better than the actual experts in this field

When the experts in the field have successfully prevented all accidents and near misses, maybe HN commenters will stop providing their input.

There is such a thing as tunnel vision in a field you have been in too long.

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#228

Post by hugh-avherald »

0xFF0123 wrote: post #199
mulmen wrote: post #187

Earlier quoted context omitted.

Europe uses pessimistic runway locks but the US prefers optimistic locks. This improves throughput at US airports with the risk of a rollback on a dirty runway.

I'd be curious to know how much it actually improves throughput. It seems strange to use optimistic locks in such a safety critical process, when a more fail-safe approach is available.

It's worth noting that the ICAO system is not perfect from a safety point of view: it often results in the controller saying 'Expect late landing clearance' instead, and clearance to land very close to the ground. As an ICAO-based pilot, I genuinely don't know which is safer. (And I also don't think the difference was important here.)

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#229

Post by the_mitsuhiko »

bagels wrote: post #78
catminou wrote: post #46

Reminds me of a time in 1999 when a US Air crew at Rhode Island refused to takeoff in the fog when the controller insisted it was okay. Another aircraft had landed and was lost in the fog about their location, even saying they were on on an active runway and even said an aircraft just took off (over them). Animation + text here if curious: https://youtu.be/qUDFY5qlTSA

That one is pretty infuriating to listen to!

The full version is worse: https://www.youtube.com/watch?v=V7AP-8uZWxA

Re: ‘Confirming we are cleared to land?’ Who said what at Austin

#230

Post by piva00 »

hef19898 wrote: post #139
EdwardDiego wrote: post #136

Earlier quoted context omitted.

Well, I'm fucked if I assume that it's working as intended, and fucked if I don't, because as you say, I'm entirely reliant on professionals doing their job correctly when I'm flying. And that professionalism seems to have failed in parts in this circumstance. (And has been well noted to have failed in many other circumstances with often tragic consequences.) All that aside, I still want to understand why the Austin…

No idea about Austin airport. Regarding professionalism and failure, the Austin incident is actually proof of the system working as intended. There was, by the looks of it, only one real mistake made, maybe two. Training of everyone involved, including the ATC, prevented those mistakes from creating a cascade of failures that could have let to two hull losses and 100+ dead passenger on the Southwest flight. For fatal…

I don't think Austin is proof of the system working as intended, the only thing that saved them was the FedEx flight being able to take action at the last moment during their approach, if the fog was a little thicker and they couldn't see the Southwest flight on the runway as early as they did it would be a catastrophe.

That's just luck, not a system that's working as intended.

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