Heads should roll at Boeing

[Hanley]

remote exploits

I was too having nightmares about the potential proximal exploits

[Root]

All I'm saying is that if you are so shocked they fixed this with a software solution then I hope you never look into virtually any technology you use for transportation daily.

I don't doubt that a parallel example exists in the automobile world, but I can't think of one. Can you? I'm not just talking about a computer system that performs a function that keeps me from crashing, I'm talking about fixing a (potentially lethal) fundamental mechanical problem with an added piece of complexity instead of fixing the fundamental problem.

[Les]

The problem with fixing a fundamental mechanical problem with software is that you are adding potential points of failure, and therefore adding risk.

How mechanically stable is a multi rotor drone without the software controlling engine speeds?

I don't know, probably not very stable. Why do you ask?

Because it's an example of fixing a fundamental mechanical problem with software.

Since it's a drone, you will have to have some kind of programming I would imagine. But the question would be, does the computer set RPM for each rotor, or does the computer regulate the pitch angle on the rotor? In a human environment, you set the RPM (this is airplanes, I don't fly helos), and a mechanical system changes the pitch angle to maintain RPM. So if the drone is doing the job of a human by setting RPM, I guess you would need that programming. But having a program control the pitch when I mechanical system can already do that job might be an example of unnecessary programming? Again, I don't know drones, but I was thinking of an example of a fixed wing drone. The same concept may apply.

Yeah, to echo JonA, I would guess for cost reasons they use fixed blades, and electric motors that size can change speed quickly enough it shouldn't be a problem at all to regulate speed pretty closely.

That makes sense with electic motors/fixed pitch blades. I was thinking something bigger with constant speed propellers and turbine engines. When I was flight instructing at KGTR, there was a company that had fixed wing/dirigible drone they were testing. The company was called Aurora.

[Les]

The problem with fixing a fundamental mechanical problem with software is that you are adding potential points of failure, and therefore adding risk.

How mechanically stable is a multi rotor drone without the software controlling engine speeds?

I don't know, probably not very stable. Why do you ask?

Because it's an example of fixing a fundamental mechanical problem with software.

Since it's a drone, you will have to have some kind of programming I would imagine. But the question would be, does the computer set RPM for each rotor, or does the computer regulate the pitch angle on the rotor? In a human environment, you set the RPM (this is airplanes, I don't fly helos), and a mechanical system changes the pitch angle to maintain RPM. So if the drone is doing the job of a human by setting RPM, I guess you would need that programming. But having a program control the pitch when I mechanical system can already do that job might be an example of unnecessary programming? Again, I don't know drones, but I was thinking of an example of a fixed wing drone. The same concept may apply.

The controller will adjust the rpm of all the motors to get the desired movement. The flight controller will take data from a handful of sensors plus the preprogrammed flight plan and send the commands to the electronic speed controllers (whose P I D you have to manually tune per craft but is set completely with software)

Thanks for sharing, that is interesting.

[JonA]

I don't doubt that a parallel example exists in the automobile world, but I can't think of one. Can you? I'm not just talking about a computer system that performs a function that keeps me from crashing, I'm talking about fixing a (potentially lethal) fundamental mechanical problem with an added piece of complexity instead of fixing the fundamental problem.

Traction control is literally a life saving function for RWD vehicles in the snowy and/or slippery conditions. (That could be fundamentally fixed by changing to AWD/4WD/FWD )

[damufunman]

I don't doubt that a parallel example exists in the automobile world, but I can't think of one. Can you? I'm not just talking about a computer system that performs a function that keeps me from crashing, I'm talking about fixing a (potentially lethal) fundamental mechanical problem with an added piece of complexity instead of fixing the fundamental problem.

Traction control is literally a life saving function for RWD vehicles in the snowy and/or slippery conditions. (That could be fundamentally fixed by fitting snow tires )

FTFY. But yeah, RWD can also become unstable, and traction control is a software fix. Though I would argue (not very strongly) not quite the same as unstable altitude in control in aircraft.

[Savs]

I don't doubt that a parallel example exists in the automobile world, but I can't think of one. Can you? I'm not just talking about a computer system that performs a function that keeps me from crashing, I'm talking about fixing a (potentially lethal) fundamental mechanical problem with an added piece of complexity instead of fixing the fundamental problem.

Traction control is literally a life saving function for RWD vehicles in the snowy and/or slippery conditions. (That could be fundamentally fixed by changing to AWD/4WD/FWD )

You're not comparing similar systems. An automobile is not designed to transport hundreds of people. Not all autos are driven in snowy, icy conditions. A loss of traction in such conditions does not automatically result in death. And a failure of the traction control system, for those autos that have it and have it turned on, does not automatically result in death.

I think a similar comparison would be to say I've designed a car that carries 350 people and whenever the driver accelerates, the car swerves into oncoming traffic. Or better yet, I've designed a monorail over a deep ravine, and whenever the driver accelerates, the train jumps the track. To stop that from happening, I've added some feedback and controller circuitry.

Anything wrong with that^ criticism/analysis?

ETA: damufunman, I agree with you. "though I would argue (not very strongly) not quite the same as unstable altitude in control in aircraft designed to transport hundreds of people." bolded text is mine, and that's my take on it. That's the nuance, I guess.

[Hanley]

Why is my shit not fucking posting

The phpBB forum software has a sentiment analysis feature that acts as a control function. It complicates the posting process when it determines that a user hasn't read the document in a thread explicitly about said document.

[Root]

Why is my shit not fucking posting

The phpBB forum software has a sentiment analysis feature that acts as a control function. It complicates the posting process when it determines that a user hasn't read the document in a thread explicitly about said document.

if he'd taken an Internet Theory class, he'd know that.

[damufunman]

The central point of this article is the inherent problem of slapping a control system on a very complex and mechanically unsound machine.

I think there is a faulty assumption that a control system wasn't already in place in the older models to make them fly stable*. To my expert eye, all 737's look like they'd have pitch problems.

* Similar to a few years back when people suddenly became terrified to learn the the accelerator of their Toyota wasn't directly connected to a throttle cable, despite the fact that it had been that way for *years* without incident.

I was actually going to bring up a similar point.

IN FACT. Now that I'm reading it, the article states there is software in place to give pilots the feel that they're physically moving stuff on the plane, even there is no physical connection between the steering wheel(?) and the rudders or w/e is controlled on the wings.

I think haptic feedback is pretty common when tactile cues can be helpful in understanding what's going on, such as with steering systems. But they're often redundant (though possibly less so these days, not sure). But if you were nosing up, and then felt the control column go light, that would indicate that the nose-up force disappeared, and you have either lost control of it or it has been corrected. At that point, being able to take over seems like it would be helpful.

[Root]

The RWD example is not a good analogy. RWD is old technology, and a fundamentally bad way to power a car in anything but ideal conditions, For that reason, they have fixed the problem on most new cars. If you buy RWD these days, you know the limitations.

The AWD/RWD example would have to go like this
1. All cars have historically had AWD
2. Because of some physical problem with implementing AWD, Buick releases a car with only RWD
3. Buick realizes that RWD sucks in the snow, so instead of figuring out how to make the new car AWD, they invent traction control.
4. Buick tells people that they can drive these cars as if they had AWD.
5. People die.

[JonA]

This is a good article, (poison the well) including some interesting quotes from an MIT professor of aeronautics (appeal to authority):

https://www.forbes.com/sites/petercohan ... a202da40aa

[Savs]

This is a good article, (poison the well) including some interesting quotes from an MIT professor of aeronautics (appeal to authority):

https://www.forbes.com/sites/petercohan ... a202da40aa

Wonder why he changed his tune five days later. Hmmm. I see his funding comes from the FAA. I'm not saying there is funny business, but there sure could be.

[JonA]

This is a good article, (poison the well) including some interesting quotes from an MIT professor of aeronautics (appeal to authority):

https://www.forbes.com/sites/petercohan ... a202da40aa

Wonder why he changed his tune five days later. Hmmm. I see his funding comes from the FAA. I'm not saying there is funny business, but there sure could be.

That's an excellent point. In light of that, I guess he doesn't seem very credible, especially compared to the guy who claims to have written the first social media platform back in 1977 and recently flew a 757 in a flight sim.

[mgil]

I dunno about this RWD speak.

With the steering and force application separated, it sometimes comes in handy in avoiding peril. For instance, a trained driver can induce oversteer and as a result change the vehicle trajectory while maintaining velocity as needed. With FWD or AWD, understeer is the norm. While this is typically safer, it is not a given. Also, RWD usually favors a more neutral weight distribution which results in a better central moment for cornering and braking.

FWD wasn’t created for safety. It was created because it’s cheaper for vehicle assembly (the entire drivetrain installs into the chassis at once) and it has lower drivetrain losses (less inertia) and thus better fuel economy.

Drivetrain choice relies heavily on application. I don’t think it applies well to this airplane design problem.

[CamLeslie]

Tomorrow I will be looking to buy some Boeing stock (BA) after their 1st quarter earnings report.

[Les]

The central point of this article is the inherent problem of slapping a control system on a very complex and mechanically unsound machine.

I think there is a faulty assumption that a control system wasn't already in place in the older models to make them fly stable*. To my expert eye, all 737's look like they'd have pitch problems.

* Similar to a few years back when people suddenly became terrified to learn the the accelerator of their Toyota wasn't directly connected to a throttle cable, despite the fact that it had been that way for *years* without incident.

I was actually going to bring up a similar point.

IN FACT. Now that I'm reading it, the article states there is software in place to give pilots the feel that they're physically moving stuff on the plane, even there is no physical connection between the steering wheel(?) and the rudders or w/e is controlled on the wings.

I think haptic feedback is pretty common when tactile cues can be helpful in understanding what's going on, such as with steering systems. But they're often redundant (though possibly less so these days, not sure). But if you were nosing up, and then felt the control column go light, that would indicate that the nose-up force disappeared, and you have either lost control of it or it has been corrected. At that point, being able to take over seems like it would be helpful.

I'm sure the tactile cues help, which is why they have stick shakers and pushers. But I would never go by feel controlling an aircraft. For instance, if you go missed on an instrument approach in IMC, adding power will make it "feel" like the nose attitude is pitching up more than it really is. This is where flying the instruments is important. And as the airplane becomes more complex, the less I would rely on kinesthetic sense. Flying VMC in a Cessna, you can really just look outside and not pay much attention to the instruments. In reality you need to do both, but you are taught to use visual and audible cues to help fly the aircraft. In IMC, you can pay attention to those (like the sound of prop RPM increasing on a fixed pitch propeller), but the main focus is flying your instruments. Moving onto a jet or bigger plane, there is less feel to flying, and it is more about just flying the numbers.

I can think of another situation where feeling got the pilots in trouble. It was an Airbus departing from New York, and it got into wake turbulence. I guess the rudder deflection/pressure in the simulator was different than the real aircraft. So the pilot over corrected which caused that surface to detach from the airplane. And in this scenario, looking at the instruments wouldn't really help. So the tactile feedback is still important. But if the airplane is pitching nose up, and the controls feel odd, but the instruments are still showing me in a climb with an airspeed decrease, etc., I'm going to trust the instruments.

[Savs]

This is a good article, (poison the well) including some interesting quotes from an MIT professor of aeronautics (appeal to authority):

https://www.forbes.com/sites/petercohan ... a202da40aa

Wonder why he changed his tune five days later. Hmmm. I see his funding comes from the FAA. I'm not saying there is funny business, but there sure could be.

That's an excellent point. In light of that, I guess he doesn't seem very credible, especially compared to the guy who claims to have written the first social media platform back in 1977 and recently flew a 757 in a flight sim.

I don't know the guy. It's quite possible he has a sterling reputation for credibility. It seems to me, though, he contradicts himself in the space of a few days, and I wonder why.

It's also true that I don't trust many engineers in academia, and I'm very sorry if that offends some people. I have worked closely with many engineering professors, have been coauthors on some of their papers, and there are quite a few I greatly admire. However, it is a little different than pure science, and that's all I'm going to say.

[Hanley]

This is called an unstable or divergent condition. It should be noted that many high performance aircraft have this tendency but it is not acceptable in transport category aircraft [emphasis mine] where there is a requirement that the aircraft is stable and returns to a steady condition if no forces are applied to the controls.

That's some fucking nuance.

So organic-agent manipulating actuators = bad?

Controller system manipulating actuators = a'ight?

EDIT: I'm assuming this is requirement in the US Code? If someone is familiar with the actual code, can you post? Really curious.

[JonA]

It seems to me, though, he contradicts himself in the space of a few days, and I wonder why.

I guess I'm not seeing the contradiction. Can you point it out to me?