A cura di @noranta4.
IEEE Spectrum – una pubblicazione dell’Institute for Electrical and Electronics Engineers – ha pubblicato un articolo d’opinione sugli incidenti dei Boeing 737 Max 8 di Ethiopian Airlines e Lion Air di Gregory Travis, pilota e ingegnere del software di esperienza decennale.
Travis si sofferma in particolare sul nuovo computer di volo e il sistema MCAS:
Apparently the 737 Max pitched up a bit too much for comfort on power application as well as at already-high angles of attack. It violated that most ancient of aviation canons and probably violated the certification criteria of the U.S. Federal Aviation Administration. But instead of going back to the drawing board and getting the airframe hardware right (more on that below), Boeing relied on something called the “Maneuvering Characteristics Augmentation System,” or MCAS.
Boeing’s solution to its hardware problem was software.
E sulle scelte di design dell’interazione uomo-macchina del sistema di autopilot.
Long ago there was a joke that in the future planes would fly themselves, and the only thing in the cockpit would be a pilot and a dog. The pilot’s job was to make the passengers comfortable that someone was up front. The dog’s job was to bite the pilot if he tried to touch anything.
On the 737, Boeing not only included the requisite redundancy in instrumentation and sensors, it also included redundant flight computers—one on the pilot’s side, the other on the copilot’s side. The flight computers do a lot of things, but their main job is to fly the plane when commanded to do so and to make sure the human pilots don’t do anything wrong when they’re flying it. The latter is called “envelope protection.”
Let’s just call it what it is: the bitey dog.
Sono particolarmente interessanti diversi commenti in calce all’articolo. Chris Travers ad esempio spiega il diverso sistema di Airbus.
Immagine da Wikimedia.