They said the same thing at Toyota when the unintended accel problem was in the news, but never found a real world example. There are a lot more old Toyotas still on the road than Airbuses in the air, so distance to the sun makes all the difference here? I wonder if they only see issues when flying near the north pole?
Airbus A320 – intense solar radiation may corrupt data critical for flight
131–140 of 184 posts
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#132I've noticed that some carriers seem to be suggesting that there might be no impact to flights, but isn't this an immediate grounding for each aircraft until the update is made? How is it possible that this wouldn't impact upon flight schedules?
If possible for exact this plane, could make software update just as routine procedure.
But as I hear, air transporters could buy planes in different configurations, so for example, Emirates airlines, or Lufthansa always buy planes with all features included, but small Asian airlines could buy limited configuration (even without some safety indicators).
So for Emirates or Lufthansa, will need one empty flight to home airport, but for small airline will need to flight to some large maintenance base (or to factory base) and wait in queue there (you could find in internet images of Boeing factory base with lot of grounded 737-MAXes few years ago).
So for Emirates or Lufthansa will be minimal impact to flights (just like replacement of bus), but for small airlines things could be much worse.
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#133Why would a CME disrupt a single brand and model of aircraft, when the entire planet is covered in computers that almost never have bitflip issues when a CME rolls through every few months?
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#134Earlier quoted context omitted.
proper SEU mitigation goes far beyond ECC. Satellites fly higher than the A320, and they (at least the ones I know about) use Triple Modular Redundancy: https://en.wikipedia.org/wiki/Triple_modular_redundancy https://en.wikipedia.org/wiki/Single-event_upset For manned spaceflight, NASA ups N from 3 to 5. Other mitigations include completely disabling all CPU caches (with a big performance hit), and continuously refre…
In redundant systems like these, how do you avoid the voting circuit becoming a single point of failure? Eg. I could understand if each subsystem had its own actuators and they were designed so any 3 could aerodynamically override the other 2, but I don't think that's how it works in practice.
In some cases, it is exactly the case of multiple independent actuators, such that the "voting" is effectively performed by the physical mechanism of the control surface.
In other cases all of the subsystems implement the comparison logic and "vote themselves out" if their outputs diverge from the others. A lot of aircraft control systems are structured more as primary/secondary/backup where there is a defined order of reversion in case of disagreement, rather than voting between equals.
But, more generally, it is very hard to eliminate all possible single points of failure in complex control systems, and there are many cases of previously unknown failure points appearing years or decades into service. Any sort of multi-drop shared data bus is very vulnerable to common failures, and this is a big part of the switch to ethernet-derived switched avionics systems (e.g. Afdx) from older multi-drop serial busses.
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#135Why would a CME disrupt a single brand and model of aircraft, when the entire planet is covered in computers that almost never have bitflip issues when a CME rolls through every few months?
I'm guessing EM shielding flaw or something electronic. See my comment on the Toyotas. It doesn't make sense from a raw probability perspective.
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#136Earlier quoted context omitted.
I don't know about the A320 but this was certainly the model for the Eurofighter. One of my university professors was in one of the teams, they were given the specs and not allowed to communicate with the other teams in any way during the hw and sw development.
> they were given the specs and not allowed to communicate with the other teams in any way during the hw and sw development. Jeez, it would drive me _up the wall_. Let's say I could somewhat justify the security concerns, but this seems like it severely hampers the ability to design the system. And it seems like a safety concern.
How so? It’s a safety measure at least as much as a security one.
It’s essentially a very intentional trade-off between groupthink and the wisdom of crowds, but it lands on a very different point on that scale than most other systems.
Arguably the track record of Airbus’s fly-by-wire does them some justice for that decision.
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#137Why would a CME disrupt a single brand and model of aircraft, when the entire planet is covered in computers that almost never have bitflip issues when a CME rolls through every few months?
I would guess barely enough cable shielding paired with long enough paths along the aircraft so that the signals there would be more likely affected by EM induced currents.
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#138Earlier quoted context omitted.
Large portions of this comment provides zero to negative value. You've quoted two LLMs and couched it in "caveat emptor" and "so I'm not sure". The rest of your comment has then mused over this data you do not trust using generalities ("my profession" are you a JS S/W eng? A chip design specialist at ARM? A security researcher?). All of the value of your comment comes from the first sentence and the last two.
Sheesh, tough crowd.
Feel free to consult LLMs, with all their downsides (like you needing to verify what they say, because it could be totally wrong).
What you're doing here is half the job: consulting an LLM and sharing the output without verifying whether it is true. You're then saying 'okay everyone else, finish my job for me, specifically the hard part of it (the verification), while I did the easy part (asking a magic 8 ball)'.
From this perspective, your comment could be viewed as disrespectful of others by asking them to finish your job, and of negative value because it could be totally hallucinated and false, and you didn't care enough about others to find out before posting it.
tl;dr: 'I asked an LLM and it said X' will likely, for the near future, be downvoted just like 'I flipped a coin and it said X'. You should be pretty confident that what you post is not false before posting it, regardless of how you came up with it.
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#139Earlier quoted context omitted.
The idea was to build three completely different systems to produce the same data, so that an error or problem in one could not be reasonably replicated in the others. In a case such as this, even ideas about algorithms could result in undesirable similarities that could end up propagating an attack surface, a logic error, or a hardware weakness or vulnerability. The desired result is that the teas solve the problem…
And did they? Sometimes the solution is obvious, such that if you ask three engineers to solve it you’ll get three copies of the same solution, whereas that might not happen if they’re able to communicate. I’m sure they knew what they were doing, but I wonder how they avoided that scenario.
Even with the same approach, I imagine the implementation could differ enough to still meet the goal. But I’m also curious if the differences were actually quantified after the fact, it seems an important step.
Re: Airbus A320 – intense solar radiation may corrupt data critical for flight
#140Apparently the fix is reverting to a previous version of the SW (see https://avherald.com/h?article=52f1ffc3&opt=0 ) Curious what a sw change might have done in terms of resiliency. Maybe an incorrect memory setting or some code path that is not calculating things redundantly maybe?
So it's not just Boeing that can screw up software on an airplane. I guess now I have to be a little afraid of all the airliners.