> Modern airliners have zero single points of failure. Safer to say that they're designed and certified attempting to have no single points of failure. E.g. t

> Modern airliners have zero single points of failure. Safer to say that they're designed and certified attempting to have no single points of failure. E.g. the MD-83 stab trim jackscrew system. Two nuts were used on the acme screw, on different portions of the screw, driven by redundant gearboxes and motors: no single point of failure! But there were common-mode failures stripping the screw and nuts.