Boeing offered the single angle-of-attack sensor as standard equipment, and charged extra for a second along with a “disagree” indicator that would allow 737 MA

Boeing offered the single angle-of-attack sensor as standard equipment, and charged extra for a second along with a “disagree” indicator that would allow 737 MAX pilots to “cross-check” a faulty sensor. Yeah, that's factually incorrect. All 737 NG/MAX planes have two alpha vanes to detect the angle-of-attack. MCAS only ever uses one at a time. Edit: You can see them both plainly in pictures: https://www.planespotters.net/photo/806268/pk-lqg-lion-air-boeing-737-8-max https://www.planespotters.net/photo/806268/pk-lqg-lion-air-b... https://www.jetphotos.com/photo/8686917 https://www.jetphotos.com/photo/8686917