I paste the picture once more, so our imagination is not stressed too much while discussing point 1,2,3:
In no way am I disputing that the MAX has a horrible record or that it is safe-enough. The graph is a retrospective number and isn't useful for some of the things it is implied to be.
It does not imply anything about the future. It just shows why this thread should focus on the MAX (because fixing the mistakes of the MAX has by far the largest leverage) and not on pilot training (because the effect of pilot training is just ground noise compared to the safety improvement that will come from the MAX fix).
The point still remains that if you could solve, totally, the 2 to 3 problem via pilot training, you would not need to solve the 1 to 2.
2 to 3 for most peope is solved. Look where the curve was a decade or two ago.
Also, don't forget, 100% safety is utopic as the curve is asymptotic!!
This means, that 0 fatalities will only be reached if year → ∞. The same applies to the associated cost. E.g. reducing the death toll per RPK by 100 in 1970 did cost the airlines a fraction of the cost, that did cost the same improvement in 1980. And today, the cost to reduce that function by another 100 can be considered unbearable. In other words, nobody will pay the price, that the reduction of that curve by another 100 would cost.
The decision to return MAX to service needs to be based on the belief of future loss rates.
Yes, I believe the MAX need to be at point 2 after the fix (in line with all the other aircraft out there).
Even if MAX had continued flying the predicted fatalities per 100 million RPK would not be 4550.
What are you talking about? The 4550 are just the fatalities per MAX RPK to this date brought into the scale of the diagram. Hello? Fatalities per trillion RPKs is just a scale! I can express any danger in transportation in that diagram, I just need to apply the correct scale. I could present the danger of driving my bike in that diagram. So I repeat, the 4550 are the fatalities per MAX RPK brought into the scale of the diagram. Nothing else.
I expected, that people would understand this (and that it does not mean, that after one trillion MAX RPKs the 4550 will be dead).
The diagram had another purpose. It nicely shows how little effect there is to be gained from more training (2 -> 3) and how crucial fixing the MAX is (1 -> 2). The dimension of the former problem is tiny compared to the MAX problem. Look at the diagram! Training makes up for a tiny portion of the problem!
No matter how you try to spin it, the graph is mathematically correct but theoretically flawed and essentially worthless in describing past risk, the exact causes of the gap, and obviously predicting future risk. It's assumes that the gap from 2 and 3 has absolutely nothing to do with the gap from 1 to 2, and that is not known. In fact, it's the opposite.
You make a lot of bold claims without substance. Let me explain:
The evidence strongly shows that the 2-3 gap is a factor in creating the size of the 1-2 gap. How much? We can't say exactly where,...
I can. Go to the second page of this thread. There is a post in which I explain. Before I quote the post once more let me summarize:
1. It is known how frequently aircraft crash due to pilot error
2. And it is also known how frequently aircraft crash due to technical faults (-> much less often than 1.)
3. The sum of the failure rates of each components (here: pilots and the aircraft itself) is the global crash rate
If you take these 3 figures, take them as the global standard, then consider the crash rate as failure rate (for 1. -> crash causing failure rate of pilots, for 2 -> crash causing failure rate of aircraft, for 3. -> The sum of both = global failure rate = number of crashes per flight globally) and finally compare them with how the MAX fared
, then you see, that the MAX has magnitudes of orders worse stats than the global standard.
And because we looked at the contributing failures rates separately, we can now isolate the MAX as the single factor, that was causing the misery. It does also pass the logic test: the equally bad trained pilots did not cause notable peaks in the statistics as long as they flew anything else than the MAX. The MAX is the single factor that changed. Anything else is at point 2 in the graph already.
More details about the calculation can be taken from this post (and before you lose your temper read the additivity section under this link https://en.wikipedia.org/wiki/Failure_rate
I can even put it mathematically with the failure rate addition formula:
Λ crash = Λ pilot + Λ aircraft (in the context where failure is defined as a crash causing mishap).
In aviation prior the MAX, this figure was ever improving. The average between 2012 and 2017 was 0.00000024 crashes per flight. "Λ pilot" being the majority (just guessing: maybe 0.00000021) and "Λ aircraft" being the rest (0.00000003). The statistics are from this link: https://www.reuters.com/article/us-airl ... SKCN1OW007
The same formula with the MAX however looks like this:
flights: 250k (educated guess, derived from my educated guess, that the MAX totally flew 516khrs)
These values give:
Λ crash = 0.000008 (33 times worse than aviation prior the MAX!!!)
Modify the formula to get the failure rate contributed by the MAX:
Λ MAX = Λ crash - Λ pilot
Now lets put in the same Λ pilot as above (because, as I said a hundreds of time: MAX pilots were not trained less than NG pilots):
Λ MAX = 0.000008 - 0.00000021 = 0.00000779
And now, this is the bummer and the real scandal: "Λ MAX" is 260 times worse than "Λ aircraft" in a world sans MAX!!!!!
In plain words this means, that the MAX has a (crash causing) system failure rate 260 times higher than the (crash causing) technical system failure rate in aviation prior the MAX.
How anybody can entertain the pilot discussion in the light of these numbers is beyond me.
You won't stop will you.
On the other hand if the ET training system had trained there Pilots properly on the MCAS procedure - the crash rate would be half. Or if Lionair had bothered training proper CRM like they were was supposed to after AirAsia 8501 as dictated by their regulator - Lionair might never have happened either. The Captain might have finally figured out that turning off the Electric Trim was a good idea if the First Officer had actually been able to trim properly and keep it in the air for more than a few seconds, just like the prior flight did.
Better training could have kept the MAX at normal safety rates.
Why do you demand the pilots to fix broken aircraft? As evidenced above, the MAX was broken on a level which was magnitudes of orders worse than typical (260 higher crash causing technical failure rate than the expected average from all other aircraft).
Last edited by rheinwaldner
on Thu Nov 28, 2019 9:21 pm, edited 1 time in total.