Re:Boeing Built Deadly Assumptions into 737 Max, Blind to a ...
by lisper on Saturday June 01, 2019 @03:26PM
(#20071027)
> what is the probability that a two-sensor model will fail pretty soon as well
It's actually higher than the probability that a one-sensor version will fail. With two sensors, you have an effective failure if either sensor fails, and the probability of that happening is roughly twice the probability that a single sensor will fail (assuming failures are independent, which is not necessarily a valid assumption).
However, with two sensors you can tell when one has failed (even though you may not know which one it was) and so the consequences of the failure might be less severe.
The problem is: now pilots need to be prepared to fly the plane with a failure sensor, which is to say, without MCAS. To do that, they will need additional training. Avoiding that was the whole point of MCAS in the first place. That's the reason it's taking so long to sort this out. Technically, it's an easy problem to solve. It's the economics that are daunting.
It's actually higher than the probability that a one-sensor version will fail. With two sensors, you have an effective failure if either sensor fails, and the probability of that happening is roughly twice the probability that a single sensor will fail (assuming failures are independent, which is not necessarily a valid assumption).
However, with two sensors you can tell when one has failed (even though you may not know which one it was) and so the consequences of the failure might be less severe.
The problem is: now pilots need to be prepared to fly the plane with a failure sensor, which is to say, without MCAS. To do that, they will need additional training. Avoiding that was the whole point of MCAS in the first place. That's the reason it's taking so long to sort this out. Technically, it's an easy problem to solve. It's the economics that are daunting.