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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

#261

Post by xwolfi »

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.

Well I mean there are many optimistic stuff in american culture that seem nonsensical to us Europeans: for instance giving everyone guns to protect against the government's army is an optimistic view of human nature and I d rather give no gun to anyone instead :D

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

#263

Post by zmgsabst »

barelyauser wrote: post #245
mcv wrote: post #223

Earlier quoted context omitted.

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 f…

Risk will always exist. Our most precious resource is time. Every effort to save it is worth it. What if it causes one accident every 20 years? It saved thousands of years of human time in the meantime.

Based on Google numbers:

There’s 16M flights per year, so saving 5 minutes each is 80M minutes, which corresponds to 160 years.

A plane crash will kill about 160 people; so if one happens every twenty years, then we’ll have saved lives if the average age is over 50 (within 20 years of natural death) and lost lives otherwise.

Personally, seems a bad gamble.

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

#264

Post by ninjagoo »

cjrp wrote: post #218
kelnos wrote: post #114

Earlier quoted context omitted.

Or hell, they could have taken the even-safer option and informed ATC they were going to hold until FedEx landed. Regardless, I think it's too early to lay definitive blame until the NTSB report comes out.

Commercial pressures. Holding for Fedex would have added a few mins, maybe lost them their place in the queue, etc. It's not a reason to act unsafely, but it is a factor.

> Commercial pressures. Holding for Fedex would have added a few mins

They spent a minute extra before starting their takeoff roll; it wouldn't have hurt to wait an additional 5 minutes. Commercial flights build in a generous margin for ground ops these days. I doubt this was a factor in this specific case.

> maybe lost them their place in the queue, etc.

They were at the runway already, there's no way for them to have lost their place in the queue for that runway 18L [1].

[1] https://upload.wikimedia.org/wikipedia/commons/a/a9/AUSFAA.p...

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

#265

Post by xwolfi »

dsfyu404ed wrote: post #233
mcv wrote: post #223

Earlier quoted context omitted.

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 f…

> Sounds like a money problem to me. Less time between planes means more planes means more money. Everything is a money/greed problem if you look at it through the lens of motivated reasoning. The usage of infrastructure is mutually beneficial. The airport, the various businesses operating at it, the customers, everyone benefits per flight. Likewise you want to make that infrastructure get used as much as possible. W…

But why does it work fine everywhere else ? It's not like we all follow the US model, yet our airports are fine and our airplanes dont crash over silly cost cuts.

There must be something the americans do wrong, somewhere, and optimisation cannot be an excuse for mediocrity. Do it fast and safe or do it slow and safe: the passengers can wait, or build their own planes and airports if they think they can do better.

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

#266

Post by coredog64 »

SQueeeeeL wrote: post #142
zackbloom wrote: post #123

Just to give a little context as a pilot: It is the job of the tower controller to decide who uses the runway when. There are often multiple planes waiting to take off, and multiple planes nearing the airport to land. It's not uncommon for a tower controller to allow a plane to takeoff while another is approaching the runway. The theory is, of course, that the flight will depart in plenty of time. In this case, the c…

I'm not sure how many people know this, but one of the first instances of "union busting" ever committed by the US federal govt was against air traffic controllers. The job used to be extremely competitive and prestigious, but overall lower wages and security has made it way harder to attract as many highly talented individuals. And with how many rules there are in that pdf, it's shocking we don't see multiple accide…

PATCO went on an illegal strike, continued the strike in contravention of court orders, and then remained on strike after a deadline from the president.

They could have returned prior to the final deadline, they could have had a sick-out, they could have worked to rule.

I’m sympathetic to labor demands, but if your oath of office makes it illegal to strike and you participate in a walkout, well, that’s on you.

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

#267

Post by moring »

kqr wrote: post #117
bigiain wrote: post #88

Earlier quoted context omitted.

I see aircraft (and even airport ground vehicles) on the runway all the time on my ADS-B setup. They 100% have them, just nobody was looking at them at the right time.

I find that in stressful and risky situations people stop trusting the data in front of them. They want to believe things are alright and will keep looking for new pieces of information to confirm that, while downplaying the importance of contradictory information.

Do you know how true this is for (relatively) reliable systems such as those found in aviation? I know that in everyday life, what you say is absolutely true -- I definitely stop trusting electronic systems in stressful situations -- but then I also know how they feed me misleading as well as blatantly false data all the time, so I'd argue that not trusting them is not irrational per se.

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

#268

Post by dsfyu404ed »

xwolfi wrote: post #261
0xFF0123 wrote: post #199

Earlier quoted context omitted.

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.

Well I mean there are many optimistic stuff in american culture that seem nonsensical to us Europeans: for instance giving everyone guns to protect against the government's army is an optimistic view of human nature and I d rather give no gun to anyone instead :D

You wouldn't even have the opportunity to make these peanut gallery potshots if those overly optimistic Yankees took the British/French/German route and did not give the general public access to ATC recordings.

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

#269

Post by ninjagoo »

EdwardDiego wrote: post #95
Animats wrote: post #94

Earlier quoted context omitted.

That's called Runway Status Lights, controlled by an Autonomous Runway Incursion System [1]. The busiest US airports have that, but Austin doesn't have one.[1][2] So the tower controllers had responsibility for separation. Here are the current FAA rules on separation between departing and arriving aircraft using the same runway. See section 3-1-3 of [3]. This is the rule: "Separate an arriving aircraft from another a…

The fact that Austin doesn't have ARIS terrifies me. It might not be the busiest airport, but it's not exactly a backwater town.

Given that Austin has been adding > 50k people annually to its population over the past many years, and now is > 2.2 Million people in the Metro area, it might be time to upgrade KAUS from Class C to Class B, or at least started on that path.

KSTL (St. Louis) and KMCI (Kansas City) are Class B, and at 10M and 7M carry fewer passengers than KAUS at 13M annually and have half the number of operations annually [1] [2].

There are many other airports on the List of Class B airports with smaller operations than Austin. [3]

[1] https://en.wikipedia.org/wiki/St._Louis_Lambert_Internationa... [2] https://en.wikipedia.org/wiki/Kansas_City_International_Airp... [3] [1] https://en.wikipedia.org/wiki/List_of_Class_B_airports_in_th...

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

#270

Post by mcronce »

zmgsabst wrote: post #263
barelyauser wrote: post #245

Earlier quoted context omitted.

Risk will always exist. Our most precious resource is time. Every effort to save it is worth it. What if it causes one accident every 20 years? It saved thousands of years of human time in the meantime.

Based on Google numbers: There’s 16M flights per year, so saving 5 minutes each is 80M minutes, which corresponds to 160 years. A plane crash will kill about 160 people; so if one happens every twenty years, then we’ll have saved lives if the average age is over 50 (within 20 years of natural death) and lost lives otherwise. Personally, seems a bad gamble.

To get from minutes of time to minutes of human time, you have to multiply the 5 minutes by the number of passengers on the flight

I don't have an opinion one way or the other on the "optimization", just pointing out the missing step in the math

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