Having zero knowledge of airplane technology, I do not know whether the following writeup/opinion piece on the 737 Max is a trustworthy source or not. It was written by a software developer (that I could verify) named Gregory Travis who claims to have been a "pilot and aircraft owner for over thirty years" and who blogged on airplane engineering in the past: https://drive.google.com/file/d/1249KS8xtIDKb5SxgpeFI6AD-PSC6nFA5/view
Travis suggests that the 737 MAX fiasco resulted from a combination of market economics/cost-optimization management and software being used to correct hardware design flaws. Here's an extensive, selective quote from this document: > "Over the years, market and technological forces pushed the 737 into larger versions with more electronic > and mechanical complexity. This is not, by any means, unique to the 737. All > airliners, enormous capital investments both for the industries that make them as well as > the customers who buy them, go through a similar growth process. > The majority of those market and technical forces allied on the side of economics, not safety. > They were allied to relentlessly drive down what the industry calls 'seat-mile costs' – the cost of flying a seat from one point to another." > > To improve capacity and efficiency (I'm still paraphrasing the document), engines had to become physically larger: > "problem: the original 737 had (by today’s standards) tiny little engines that easily cleared the ground beneath the wings. As the 737 grew and was fitted with bigger engines, the > clearance between the engines and the ground started to get a little, umm, 'tight.' [...] > > With the 737 MAX the situation became critical. [...] The solution was to extend the engine up and well in front of the wing. However, > doing so also meant that the centerline of the engine’s thrust changed. Now, when the pilots applied power to the > engine, the aircraft would have a significant propensity to 'pitch up' – raise its nose. [...] > > 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 FAA’s certification criteria. But, instead of going back to the drawing board and > getting the airframe hardware right (more on that below), Boeing’s solution was something > called the 'Maneuvering Characteristics Augmentation System,' or MCAS. > Boeing’s solution to their hardware problem was software." Software that didn't work as expected. - By itself, this story doesn't sound new, but (particularly to European readers) like a flashback from more than twenty years ago when Mercedes botched the aerodynamic design of its "A series" car (its first entry into the compact car segment) and corrected it with computerized Electronic Stability Control (ESC/ESP), a textbook example of a cybernetic feedback-and-control system based on sensors and software. Here is an article that explains the basics of Boeing's MCAS system, which sounds similar to ESC/ESP indeed: https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/ (For lay people like me, the surprising bit was that MCAS "activates automatically when [...] autopilot is off".) -F -- blog: *https://pod.thing.org/people/13a6057015b90136f896525400cd8561 <https://pod.thing.org/people/13a6057015b90136f896525400cd8561>* bio: http://floriancramer.nl
# distributed via <nettime>: no commercial use without permission # <nettime> is a moderated mailing list for net criticism, # collaborative text filtering and cultural politics of the nets # more info: http://mx.kein.org/mailman/listinfo/nettime-l # archive: http://www.nettime.org contact: nett...@kein.org # @nettime_bot tweets mail w/ sender unless #ANON is in Subject:
