[diggan]

> 737 Max is going to end up being one of the safest planes to fly in

It already has two crashes under its belt, compared to other models that never had any crashes (like the A380).

But I guess if we put the disclaimer "From today on!" then it might be accurate.

[bobsomers]

> It already has two crashes under its belt, compared to other models that never had any crashes (like the A380).

You can't come to any conclusions from simple math like that because it isn't corrected for flight hours and exposure. There are literally 10x more 737 Max's delivered so far than there are total A380s left flying, and they're constantly booked doing short to medium haul flights all day long rather than a single long-haul flight per day. And given that takeoff and landing are the riskiest phases of flight, it should also probably be corrected by flight cycles, not pure flight hours.

It's nowhere close to as simple as you make it out to be.

[diggan]

As a thought experiment, I just gonna make up some numbers then.

A380 has X flight hours, with N landings, with no crashes

737 Max has X * 10000 flight hours, with N * 10000 landings, with two crashes

No matter how you calculate it, 737 Max been through more crashes than A380, unless you ignore the previous two crashes, obviously.

[bobsomers]

> No matter how you calculate it, 737 Max been through more crashes than A380, unless you ignore the previous two crashes, obviously.

Correct, but again this is too simplistic of a view and it's not a question that gives you any real information.

Consider a brand new airplane that has never flown. It's also been in zero crashes. Is it obviously safer than the 737 Max? Clearly not, so what is the real question you want to answer?

What you really want to know is, based on the existing data, how likely is it that I will crash if fly on an A380 vs a 737 Max? This is question that ultimately hinges on the predictive power of the existing data, and when you are dealing with rare events, the data volume makes a huge difference in your confidence intervals.

Without drowning the conversation in details, if you modeled crashes as a Poisson process (which may or may not be appropriate), there are absolutely situations in which a 737 Max with 2 crashes is the obvious statistical choice over an A380 with none, simply because you have so much more data for the Max that you have tight confidence intervals around the flight not ending in a crash.

With much less data on the A380s side, the confidence intervals are wider and it's possible that it's actually more likely that your A380 becomes the first crash than that you experience the third 737 Max crash!

I'm not saying this is definitively the case, it would require lots of specific data I don't have access to and a subject matter expert to sign off on the modeling, but X is not safer than Y simply because X has a fewer total number of events.

[DriverDaily]

"end up being" is not enough of a disclaimer for you?

[vlovich123]

No, they’re correct. “End up being” does not imply that you ignore the existing track record. That’s why OP clarified “only if you ignore their existing safety record” - given that other planes have had 0 crashes and 0 fatalities, I’m not sure how the 737MAX could even ”end up” being “safer” even if you ignore existing issues - you can’t get better than 0 issues, so at best it would be as safe as most other aircraft.

[ldoughty]

A plane that has a perfect track record now may not be perfect from now on.

Meanwhile, a plane with a bad track record right now may never have another incident from now on.

So, the 737 MAX may have 2 crashes now... but every other major plane might have that many crashes (or more) over the next 30-40 years. This would make the 737 Max "One of the safest planes" generally speaking.

[vlovich123]

Maybe but the A380 had already been flying for 17 years. It seems unlikely that it’s going to have foundational issues with the program at this point vs normal things that would apply to any airplane like airlines not maintaining the air craft properly or pilot error / suicide by pilot.

[DriverDaily]

If you want to be pedantic, you're conflating 'having a safe record' with 'being safe.' It's just an indicator.

[vlovich123]

Not really. All safe planes have a safe record and a safe record implies some amount of inherent safety. Since safety is really hard to quantify and compare and in some ways is qualitative, the safety record is a justifiable and defendable proxy for comparing safety.

[DriverDaily]

We’re on the same page.

You’re acknowledging that the safety record is just a proxy for safety. That’s what I’m saying too.

I would argue that using the number of incidents as a proxy for safety ignores the trend.

[nottorp]

The thing is, it doesn't look like Boeing has learned anything.

[stefan_]

No, because it can absolutely not end up being that? 2 crashes is already a massive number, who is going to go back and make them disappear?

[User23]

It certainly isn’t for the folks involved in crash three.