[bradbot]

What kind of effects might this have on modern passenger aircraft? Specifically the digital fly-by-wire.

After seeing how poorly the US government handled the Covid response I hope I don't have to experience a major solar event such as the one described in the article.

[cpgxiii]

Realistically, limited. Passenger aircraft are routinely struck by lightning, which isn't entirely the same but is relatively similar. Given warning, I don't see airlines taking the risk, but that's driven by perceived liability rather than real risk.

Civilian FBW systems (essentially all of which are digital at this point, analog would likely be more vulnerable) are multiply-redundant which provides reasonable protection against upset events. The primary threat from solar events is the induced currents, not direct radiation that is a bigger threat to transistorized digital electronics. Flying aircraft are obviously electrically isolated from the electrical grid (which is where the real damage would take place), and relatively small (compared to hundreds of km of power lines), which would limit the range of induced currents in the airframe.

The real risk to aviation would be a loss of air traffic control which would risk mid-air collisions in busy areas.

[graderjs]

Then I'm wondering how a mobile phone could pose such a threat to an aircraft. I imagine this sort of storm would cook their instruments, or at least make them go crazy for a while, and likely induce corruption in their digital systems. As we saw with bad software in 737 max control, trouble in those systems can down craft, i think you're underestimating the risk.

There's more info on aviation affects here https://www.skybrary.aero/index.php/Impact_of_Space_Weather_...

[cpgxiii]

Mobile phones don't. There are practical and political reasons for not allowing phone use, but meaningful risk to the safety of flight is not one of them.

Instruments are fine, what could suffer problems are RF receivers (radio, radar, GNSS) but outside of interference during the event and the potential need to reboot problematic equipment, the critical instruments (pitot-static, accelerometers and gyros) aren't particularly exposed. In terms of effects to the aircraft systems directly, all that article mentions are upset events, and those are already a design consideration.

The 737-Max story came about specifically because it was not a FBW aircraft and not designed as such with sufficiently redundant systems. The safety case was that crews could disable the system if it misbehaved, rather than it being essential for flight like a real FBW system would be.

[graderjs]

Cool, that's good to know, thanks. What's your background on this that makes you qualified to answer with certainty? Also what are political reasons for no phones on flights?

[cpgxiii]

Background in electrical engineering, presently in robotics research, and a strong interest in avionics. The concerns that commercial aircraft face are shared with basically every other self-propelled electromechanical system (planes, cars, robots, spacecraft). Insufficient care in hardening these systems has resulted in (likely) fatalities before - evidence suggests that at least some of Toyota's "unintended acceleration incidents" were caused by cosmic-ray upsets in ECUs that weren't sufficiently redundant. Note that upsets are well enough understood for SpaceX to fly using redundant aerospace processors rather than the traditional radiation-hardened processors.

The political reasons are that no one wants a plane full of people talking on their phones and further distracted from listening to the safety briefing and flight crew instructions. Airlines don't want it and passengers don't want it. People do want network access on planes, which is widely available albeit slow. The only sincere technical concerns involve legacy radio equipment (ILS and glideslope), but I'm not aware of any demonstrated interference issues. Plenty of cases of interference from someone parking a large truck or 747 in front of the ILS antenna, though.

[graderjs]

Cool, thanks for that. I really appreciate your time on this. It's rare to find a real expert amongst all the speculators (of which for most topics I am one) here. :)

How many redundant processors do you need per one "effective" processor you can count on for a typical SpaceX launch?