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Comment by RetroTechie | Hacker News Reader

That assumes the environment the aircraft flies in, behaves predictable. Sometimes it does not.

Turbulence is an obvious one. Downdrafts another. You can have a perfectly functional aircraft, but if the whole air column it's in goes down faster than the aircraft can climb, the aircraft will go down with the air column no matter what.

Reminds me of an Air Crash Investigation episode: some volcano had erupted, ash was high up in the air, air traffic control wasn't aware of this, and iirc it didn't show up on weather radar or similar systems (or on the planes' systems).

So it looked all clear. Meanwhile the whole plane was getting ash-blasted. To the point that paint was stripped, cockpit windows went from clear to matte, and ash attached itself to engine fan blades. Obviously trouble followed...

Bottom line: the environment a vehicle moves through, is always a factor. Sometimes an unpredictable, uncontrollable and/or hazardous one.

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I'm not familiar with the volcano incident you referred to, but a bit of searching seems to indicate it was British Airways Flight 009 in 1982, where a 747-200 had all four engines fail due to volcanic ash… then glided safely out of the ash cloud and was able to restart three of the engines and land safely at a major airport. From a complete loss of power to all engines to on the ground with zero deaths, zero injuries. That's exactly the kind of story I'm talking about that gives me such faith in flying!

Sounds like the one! Engine after engine going out. Without (at first) any obvious cause.

> From a complete loss of power to all engines to on the ground with zero deaths, zero injuries. That's exactly the kind of story I'm talking about that gives me such faith in flying!

Understood (and agreed). But you missed my point: fate of that flight didn't result from safety engineering. It depended entirely upon the ash-laden air it flew into, and its effect on the aircraft & its engines. No amount of systems redundancy could have made it a safe flight.

So yes: flying is very safe these days. But there are limits to what safety engineering can provide.

> No amount of systems redundancy could have made it a safe flight.

But it did! One obvious example being the redundancy that allowed the plane to fly safely despite one of the engines not restarting.

The plane encountered an entirely unpredicted situation that caused damage, but thanks to its design was still able to land safely.

They got lucky because when they descended after the engines died, the engine cooling caused small physical size changes and the caked/burned ash just fell off the rotor bits allowing the engine to work again.

To RetroTechie’s point, they got lucky. No design decision saved them. Without that they’d have been a glider until they hit 0ft and it likely would have been far worse.

We’ve clearly gotten very good at flying, managing most weather conditions we’re likely to fly through, the mechanics/maintenance of the planes, and pilot training.

I’ve gained a ton of appreciation for how detailed our preparations are from watching Air Disasters. But we just can’t control everything, some danger is inherent.

Today we have VA monitoring satellites and aircraft aren't routed through VA.

That flight is why, IIRC.

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