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> The probability that two crashes are both 737 Max is 0.00875 * 0.00875 = 0.0000766 You need to multiply this by every combination of two crashes in the obser

by Steko 8y ago

> The probability that two crashes are both 737 Max is 0.00875 * 0.00875 = 0.0000766 You need to multiply this by every combination of two crashes in the observed time period with starting and endpoints not cherry picked to include 737 max crashes though.

panarky 8y ago
Be my guest. You'll find that the probability of a rare aircraft crashing twice in a short period of time is infinitesimal, unless that aircraft contributed to the catastrophe.
- Steko 8y ago
  It's hardly infinitesmal, that's my point. With an average of 175 737's operating since launch, 4K total widebody commercial aircraft and over a dozen widebody crashes in that period, you get over 10%. Some estimates there but you still have the endpoint issue as well.
  - panarky 8y ago
    There have been a total of 5 commercial air disasters in 2018 and 2019 with fatalities that didn't involve hijacking, landing short of the runway or overshooting the runway [0]. And that includes the crash of a cargo flight with no passengers where the crew was killed. The 737 Max 8 was involved in 2 of those 5 disasters. There are between 25,000 and 39,000 commercial aircraft in service depending on who you ask [1]. With 350 737 Maxes delivered so far, that's at most 1.4% of the total today, probably less than half that this time last year. Let's call it 1% on average for 2018 and 2019 combined. There are 10 ways you can have 2 Max crashes out of 5 total crashes. So the probability is 10 * 0.01^2 * 0.99^2 = 0.00098 Even accounting for n choose k and longer endpoints, it's still an infinitesimal probability that we'd see two catastrophes with the same rare aircraft -- unless that aircraft contributed to the catastrophe. It should be grounded. [0] https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_commercial_aircraft#2018 https://en.wikipedia.org/wiki/List_of_accidents_and_incident... [1] https://www.telegraph.co.uk/travel/travel-truths/how-many-planes-are-there-in-the-world/ https://www.telegraph.co.uk/travel/travel-truths/how-many-pl...

by Steko 8y ago

panarky 8y ago

Be my guest. You'll find that the probability of a rare aircraft crashing twice in a short period of time is infinitesimal, unless that aircraft contributed to the catastrophe.

Steko 8y ago
It's hardly infinitesmal, that's my point. With an average of 175 737's operating since launch, 4K total widebody commercial aircraft and over a dozen widebody crashes in that period, you get over 10%. Some estimates there but you still have the endpoint issue as well.
- panarky 8y ago
  There have been a total of 5 commercial air disasters in 2018 and 2019 with fatalities that didn't involve hijacking, landing short of the runway or overshooting the runway [0]. And that includes the crash of a cargo flight with no passengers where the crew was killed. The 737 Max 8 was involved in 2 of those 5 disasters. There are between 25,000 and 39,000 commercial aircraft in service depending on who you ask [1]. With 350 737 Maxes delivered so far, that's at most 1.4% of the total today, probably less than half that this time last year. Let's call it 1% on average for 2018 and 2019 combined. There are 10 ways you can have 2 Max crashes out of 5 total crashes. So the probability is 10 * 0.01^2 * 0.99^2 = 0.00098 Even accounting for n choose k and longer endpoints, it's still an infinitesimal probability that we'd see two catastrophes with the same rare aircraft -- unless that aircraft contributed to the catastrophe. It should be grounded. [0] https://en.wikipedia.org/wiki/List_of_accidents_and_incidents_involving_commercial_aircraft#2018 https://en.wikipedia.org/wiki/List_of_accidents_and_incident... [1] https://www.telegraph.co.uk/travel/travel-truths/how-many-planes-are-there-in-the-world/ https://www.telegraph.co.uk/travel/travel-truths/how-many-pl...