I think you're right. I misread it. My point about cost still stands. "Cockpit displays and a warning light intended to flag problems with angle-of-attack sens

I think you're right. I misread it. My point about cost still stands. "Cockpit displays and a warning light intended to flag problems with angle-of-attack sensors in flight were optional on the Lion Air jet that crashed, according to people familiar with the matter. The carrier, like some others, chose not to purchase the feature, people familiar with the matter said, so pilots didn’t receive any such alerts." https://www.wsj.com/articles/maintenance-lapse-identified-as-initial-problem-leading-to-lion-air-crash-11545739204 https://www.wsj.com/articles/maintenance-lapse-identified-as...