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Autoland saves King Air, everyone reported safe

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Re: Autoland saves King Air, everyone reported safe

#171

Post by m463 »

vjvjvjvjghv wrote: post #36
ryandrake wrote: post #28

Absolutely amazing. Well done, Garmin. Imagine getting to go to work everyday to work on something that actually saves lives. Fantastic systems engineering work.

“ Imagine getting to go to work everyday to work on something that actually saves lives.” I work on medical devices that improve and save lives but the work actually kind of sucks. You spend most of your time on documentation and develop with outdated tools. It’s important work but I would much prefer “move fast and break things”. So much more interesting.

> develop with outdated tools

I suspect a lot of aviation is the same.

Many private planes use outdated tech, carbeurated piston powered engines driving propellers.

Maintenance heavy, but all of it is well known and stable.

Re: Autoland saves King Air, everyone reported safe

#172

Post by Centigonal »

Aloha wrote: post #97
dpifke wrote: post #74

Earlier quoted context omitted.

At an untowered field, saying the airport name at the beginning and end of each transmission is standard phraseology.

In phonetics?q

Typically, at an untowered airport, it's something closer to "{airport_colloquial_name} traffic, {your_aircraft_type} {your_n_number}. {MESSAGE}, {airport_colloquial_name} traffic"

So, "Columbia traffic, Cessna november one two three alfa bravo [N123AB], three mile final, full stop, runway one eight, Columbia traffic"

At a towered airport, you'd say "Columbia tower" instead, and you don't have to repeat it at the end of your message.

Re: Autoland saves King Air, everyone reported safe

#174

Post by WalterBright »

manarth wrote: post #143
WalterBright wrote: post #57

Earlier quoted context omitted.

The AF 449 was in a stall, and the pilots panicked and did exactly the wrong thing. The pilot came out of the lavatory and immediately realized what was wrong, and pushed the stick forward. But it was too late. If the captain could figure it out, so could the computer. I recall another crash, not so long ago, of a commuter plane where the wings iced up a bit and the airplane stalled. The crew kept trying to pull the…

> "If the captain could figure it out, so could the computer." The autopilot had disengaged, most likely because the pitot tubes had iced over. The aircraft system entered ALT2 mode, where bank-angle protection is lost. Protection for angle-of-attack is also lost when 2 or more input references are lost. You might describe these circumstances as the computer saying "I don't know what the heck's going on, you humans f…

As a former engineer who worked on the 757 flight control system, I am not terribly impressed with that design.

Having 3 pitot tubes iced over means they read 0 velocity. It is reasonable for the computer to be designed to recognize that if all three pitot tubes read 0, then the pitot tubes are the problem. With the altimeter unwinding, it should be able to recognize a stall. With the turn and bank indicator, and the AOA indicator, it should be able to return to straight and level.

Recall that the captain figured it out at a glance and knew exactly what to do.

Re: Autoland saves King Air, everyone reported safe

#175

Post by WalterBright »

tjohns wrote: post #115
WalterBright wrote: post #58

Earlier quoted context omitted.

As I mentioned elsewhere, the captain figured out what was wrong immediately, but he was too late. BTW, my dad taught instrument flying in the AF. He said it was simple - look at the instruments. Bring the wings level, then the pitch level. Although simple, your body screams at you that it's wrong. He carried with him a steel pipe, so he could beat a student unconscious who panicked and would not let go of the contro…

> He carried with him a steel pipe, so he could beat a student unconscious who panicked and would not let go of the controls. Most flight instructors just keep a spare pen in their pocket to jab an uncooperative student in thigh with. (Thankfully almost never used.)

His jets were tandem, so he was behind the student. A steel pipe was the only way.

Re: Autoland saves King Air, everyone reported safe

#176

Post by WalterBright »

prmoustache wrote: post #139
WalterBright wrote: post #35

Earlier quoted context omitted.

When did that happen? I recall the Air France crash over the Atlantic where the pilots got disoriented. And many others, like JFKjr's crash.

they were disoriented because a sensor was frozen or something like that and the readings were not correct if I remember correctly, an automatic system would have received the same wrong information.

Since the captain recognized the problem and took corrective action immediately, the avionics could have done so, too.

Re: Autoland saves King Air, everyone reported safe

#177

Post by WalterBright »

mrguyorama wrote: post #168
Mawr wrote: post #155

Earlier quoted context omitted.

"and he kept overriding the other pilot who was doing the correct thing to recover from the stall he had put the aircraft in." Yep, the real design problem here is the idiocy of allowing dual input.

I will repeat this as I have had to say it before: There is no engineering fix to AF447. You cannot protect a plane from what is essentially a rogue pilot who is not restrained. It would have happened exactly the same in a Boeing. The problem was a supposedly trained and tested pilot responding to a somewhat normal event (loss of awareness and disorientation) by freaking the fuck out and throwing a plane into the oce…

My suggestion was not about overriding the "nut behind the wheel", but providing the crew with a button that says "fix it".

P.S. my lead engineer at Boeing told me they can fix everything but the "nut behind the wheel".

As I mentioned before, my dad taught instrument flying. What he'd do is go through all the maneuvers where your body gets tricked, and the student (under a blackout hood so they could only see the instruments) must recover. And they'd do it over and over, until the student stopped believing his screaming senses and trusted the instruments.

I don't know all that can be simulated in a simulator. I don't know if modern flight training is sufficient.

BTW, experiments were done with birds to see how they flew "in the soup" (zero visibility). The birds would just fold their wings and drop out of it. It seems that evolution hasn't evolved a method for navigating blind.

Re: Autoland saves King Air, everyone reported safe

#178

Post by WalterBright »

filleduchaos wrote: post #148
WalterBright wrote: post #57

Earlier quoted context omitted.

The AF 449 was in a stall, and the pilots panicked and did exactly the wrong thing. The pilot came out of the lavatory and immediately realized what was wrong, and pushed the stick forward. But it was too late. If the captain could figure it out, so could the computer. I recall another crash, not so long ago, of a commuter plane where the wings iced up a bit and the airplane stalled. The crew kept trying to pull the…

No, one of the pilots put the plane into an aerodynamic stall because they had failed sensors giving them erroneous airspeed information and he kept overriding the other pilot who was doing the correct thing to recover from the stall he had put the aircraft in. What exactly was a computer at the time supposed to figure out with unreliable data, especially after a stall had first developed? Also in fairness I was a bi…

> LVL requires the pilot to actually press it

Of course. I did say it was a button to press!

> LVL is not appropriate stall recovery

It should be. I don't see how it couldn't be designed to do stall recovery. After all, the avionics do recognize a stall (as it activates the "pull up" stick shaker).

Re: Autoland saves King Air, everyone reported safe

#179

Post by manarth »

WalterBright wrote: post #174
manarth wrote: post #143

Earlier quoted context omitted.

> "If the captain could figure it out, so could the computer." The autopilot had disengaged, most likely because the pitot tubes had iced over. The aircraft system entered ALT2 mode, where bank-angle protection is lost. Protection for angle-of-attack is also lost when 2 or more input references are lost. You might describe these circumstances as the computer saying "I don't know what the heck's going on, you humans f…

As a former engineer who worked on the 757 flight control system, I am not terribly impressed with that design. Having 3 pitot tubes iced over means they read 0 velocity. It is reasonable for the computer to be designed to recognize that if all three pitot tubes read 0, then the pitot tubes are the problem. With the altimeter unwinding, it should be able to recognize a stall. With the turn and bank indicator, and the…

The FAA report[1] gives a more comprehensive description of events.

The pitot tubes had differential icing, and didn't all read 0kts – they reported different velocity against each tube, such as 40kts or 60kts (against an expected baseline of ~ 275kts). The computer correctly recognised the data was invalid and rejected it.

It's a common narrative that the captain immediately figured out the issue. The report and transcript of the cockpit recording[2] notes that the captain's interventions showed that he had not identified the stall, nor had the copilots.

         ~ cockpit recording ~
    0:00 autopilot disconnects
    0:01 [copilot right] "I have the controls"
    0:11 [copilot right] "We haven't got a good display of speeds"
    1:26 captain enters cockpit
    1:30 [copilot right] "I don’t have control of the airplane at all"
    1:38 [captain] "Er what are you doing?"
    3:37 [captain] "No no don't climb"
    4:00 [captain] "Watch out you’re pitching up there"
    4:02 [copilot right] "Well we need to we are at four thousand feet"
    4:23 ~ recording stops ~



    [1] https://www.faa.gov/sites/faa.gov/files/AirFrance447_BEA.pdf
    [2] https://bea.aero/uploads/tx_elyextendttnews/annexe.01.en.pdf

Re: Autoland saves King Air, everyone reported safe

#180

Post by mtanski »

iamacyborg wrote: post #134
mtanski wrote: post #56

Earlier quoted context omitted.

Cane to say the same. I have a Garmin "smart" watch (with every app notification etc disabled) and I love the fact that I can do almost two weeks of exercises (ride, walk, gym) without needing to charge it. The bike computers are also solid. But sadly the UX of the software on these leaves a bunch to be desired, and I've been bitten by many software and firmware bugs in the last years... Including months for which HR…

> Including months for which HRM would randomly and persistently drop it's value from say whatever the real value (say 145 for argument sake) to 80. It’s annoying but a proper HR strap fixes all the issues associated with wrist based optical readers.

I know all of the wrist watches experience this issue, but this was extreme like drop from 145->80 for like 60+ min then rapidly shopt back up. Not like a small couple min blip.

This was a near the top end model at the time, and after complaining Garmin support owned up that this was a firmware bug impact all sensors of that generation and it would take 2+ months to fix (took like 5).

But they did send me a HRM for free and I've been using that. So I am grateful that and using it since. But for short rides (like 90 min or less) I don't always remember to think to bring the HRM.

Prior to that I had two lower end Garmin watches, and despite having theoretically lower end HR sensors they did not experience such bugs or drop outs (an unexpected blip every once in a while).

But I think the main point still stands, their software/firmware/UX has not moved in relation with the hardware. Next time I'm in the market I will be consider all the options. Feels like Coros and others have come a long way.

Prob the biggest thing keeping me in their ecosystem is multi sport (variations of bike riding types -- I do all), hiking, strength training, erg, winter sports. But even there the list of strength exercises has not been updated in like a decade.

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