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Comment by juliansimioni | Hacker News Reader

[pilot here]

There's a lot more to managing planes in bad weather than landing them: you can't exactly fly through a thunderstorm.

Furthermore, sometimes go/no-go decisions have to be made a long way out. If it looks like there might be lots of thunderstorms near your destination, it's sometimes prudent to divert immediately rather than risk being near an airport with weather too bad to land AND low fuel.

A great example is a youtube video by stevo1kinevo: he's flying a TBM 850 (fast turboprop) from Florida to Boston International. While checking the weather enroute he decides the chance of storms near Boston is too high, and with the complexity of getting in and out of a major airport, he decides well in advance to divert to an airport on Long Island. This sort of stuff happens all the time and is the very definition of good airmanship.

https://www.youtube.com/watch?v=PZzOsXya4zw

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So, one experienced pilot will need to make this decision for all roboplanes.

> you can't exactly fly through a thunderstorm.

You can't, but can a UAV? I'm curious how much more tolerant of bad weather a plane can be if there are no people inside. Are storms often strong enough to knock a plane out of the sky?

Flying by instruments, I wonder how high the risk truly is. One of the bigger concerns might be an instrument failure, like the failure of the airspeed sensors on Air France 447.

Very very high. What fuels a thunderstorm is large amounts of air rising, and falling very rapidly. When the aircraft encounters those air movements it can very quickly exceed the structural limits of the aircraft.

Some more detail: flying in rising or sinking air isn't a problem in itself, as long as you can tolerate the change in altitude. But flying from one into the other, fast, is a sure way to exceed structural load levels.

There were many failures in the cockpit of AF447. Almost all of them were aft of the instruments.

Problem exists between keyboard^H^H^H^H^H^H^H^H yoke and chair

The addition of people to the plane makes zero difference to storm survivability, why would it?

Storms are definitely regularly large enough to bring down even large aircraft, it doesn't happen often because planes of systems on board to ensure they avoid such weather, but it can happen!

https://en.wikipedia.org/wiki/Southern_Airways_Flight_242

> Are storms often strong enough to knock a plane out of the sky?

Simply put: yes. Not just any thunderstorm. All thunderstorms.

All aircraft avoid thunderstorms. It's not a case of discomfort for humans inside it; it's about the risk to aircraft themselves.

Thunderstorms contain severe updrafts and downdrafts and huge windshear between them. Aircraft cannot outclimb the downdrafts so cannot maintain altitude inside them. And severe windshear will tear them apart.

The only reason you don't hear about aircraft lost in thunderstorms is because pilots avoid them. All of them.

A friend of mine who is a glider pilot once compared thunderstorm to a steamroller.

If you get hit by the leading edge your plane will get smashed into the ground. If you somehow get to the back part, your plane might end up in the stratosphere, which might be just as fatal due to very low temperature and lack of oxygen.

He mentioned some early gliding pioneers who were insane and lucky enough managed to "ride" a thunderstorm and achieve record breaking flight distance - and somehow not getting killed in the process.

So how do hurricane hunters survive? Are hurricanes less, for lack of a better word, volatile?

> Are storms often strong enough to knock a plane out of the sky?

And then some. The forces in a run of the mill thunderstorm could rip the wings off a plane in seconds.

On the ground operator can also make those calls? Really, it's like fleet-specific air traffic controller + rc pilot.

Yeah, definitely. And thinking about it more I'm sure there are some air traffic controllers that manage 10+ airplanes fine (although they aren't as involved as the pilots, so a remote operator would have a higher workload).

I bet a fleet of commercial autonomous aircraft operation out of private facilities would also have a lot more common procedures (all their airspeeds, climb/descent rates, etc would all be the same), so it might even be easier.

Also maybe they could pool resources? Like pilots in an area where everything is fine leave their planes on full auto and go take over another plane from another pilot?

Edit: Or maybe, expect the planes to be fully auto, then have a bank of pilots available to take over any plane that is having troubles.

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