> so there was no choice but to let the humans try. They failed, but that's not an argument for not letting them try if the computers would have also failed.

> so there was no choice but to let the humans try. They failed, but that's not an argument for not letting them try if the computers would have also failed. The major issue in "letting the humans try" in the AF447 incident is that the pilots did not have the angle-of-attack measurement shown to them. AOA is the most critical flight parameter (it determines whether the wing is lifting or stalled) and while the flight computers have access to it, AOA is not displayed in the flight displays. This is a huge flaw; forcing the pilots to guesstimate AOA from airspeed readings is a horrid idea, especially if the airspeed sensors might be malfunctioning. There are already dedicated AOA sensors on the airframe and only a minor software change is needed to display AOA on the primary flight displays. This design decision of hiding critical information from the humans (what AOA is, what the other pilot is doing with their stick) is what scares me most about fly-by-wire. I get that displaying all the information that's on all the avionics busses would overwhelm the crew, but displaying AOA is not pointless verbosity, it's the most crucial air data measurement on a fixed-wing aircraft. Sullenberger agrees, "We have to infer angle of attack indirectly by referencing speed. That makes stall recognition and recovery that much more difficult. For more than half a century, we've had the capability to display Angle of Attack in the cockpits of most jet transports, one of the most critical parameters, yet we choose not to do it." So does the AF447 report, "It is essential in order to ensure flight safety to reduce the angle of attack when a stall is imminent. Only a direct readout of the angle of attack could enable crews to rapidly identify the aerodynamic situation of the aeroplane and take the actions that may be required."