Dalla pagna wikipedia [1] pare che Boeing abbia valutato di progettare un nuovo velivolo, ma ha esitato finché non è stato troppo tardi, cioè quando Airbus ha raccolto (molti) ordini per A320neo. A quel punto si sarebbe decisa al retrofit del 737 per non lasciare parte del mercato di American Airlines a Airbus, il cui successo con A320neo non era stato previsto, e soffiando l'ordine a Airbus. Non si tratterebbe quindi di una lotta competitiva per i margini, ma un autentico errore strategico a cui si è cercato di rimediare in fretta cercando scorciatoie. Il resto ha seguito l'aureo principio che (scusate il francesismo) "la fretta passa, la merda resta". L'aspetto più criminale è stato non rendere il dispositivo automatico software escludibile per non dover riaddestrare i piloti e poter spacciare il nuovo velivolo come un semplice upgrade del vecchio. Decisione mantenuta irresponsabilmente anche dopo il primo crash. Vediamo cosa succede dopo le inchieste. Alberto [1] <https://en.wikipedia.org/wiki/Boeing_737_MAX> On December 1, 2010, Boeing's competitor, Airbus, launched the Airbus A320neo family to improve fuel burn and operating efficiency with new engines: the CFM International LEAP and Pratt & Whitney PW1000G.[17] In February 2011, Boeing's CEO Jim McNerney maintained "We're going to do a new airplane."[18] At the March 2011 ISTAT conference, BCA President James Albaugh was not sure about a 737 re-engine, like Boeing CFO James A. Bell stated at the JP Morgan Aviation, Transportation and Defense conference the same month.[19] The A320neo gathered 667 commitments at the June 2011 Paris Air Show for a backlog of 1,029 units since its launch, setting an order record for a new commercial airliner.[20] On July 20, 2011, American Airlines announced an order for 460 narrowbody jets including 130 A320ceos and 130 A320neos, and intended to order 100 re-engined 737s with CFM LEAPs, pending Boeing confirmation.[21] The order broke Boeing's monopoly with the airline and forced Boeing into a re-engined 737.[22] As this sale included a Most-Favoured-Customer Clause, Airbus has to refund any difference to American if it sells to another airline at a lower price, so the European manufacturer can not give a competitive price to competitor United Airlines, leaving it to a Boeing-skewed fleet.[23] On April 21, 2019 8:58:03 AM UTC, Stefano Quintarelli <stefano@quintarelli.it> wrote: On 20/04/2019 18:10, Enrico Nardelli wrote: Mi sembra interessante sottolineare anche questi passaggi dell'articolo ------------------------------------------------------------------------ The 737 Max saga teaches us not only about the limits of technology and the risks of complexity, it teaches us about our real priorities. Today, safety doesn’t come first — money comes first, and safety’s only utility in that regard is in helping to keep the money coming. The problem is getting worse because our devices are increasingly dominated by something that’s all too easy to manipulate: software. a me sembra che "sopravvivenza comes first". non credo che i margini di boeing ed airbus siano radicalemente diversi (non ho controllato). boeing pare aver cercato la strada breve del sw (compromettendo la sicurezza) per poter rimanere competitiva nei confronti di airbus che (apparentemente) questi problemi di sicurezza non ha. se boeing avesse dovuto rifare tutto il processo come un velivolo nuovo, sarebbe stata fuori mercato e quindi (probabilmente) morta... ... Software defects, on the other hand, are easy and cheap to fix. All you need to do is post an update and push out a patch. What’s more, we’ve trained consumers to consider this normal, whether it’s an update to my desktop operating systems or the patches that get posted automatically to my Tesla while I sleep. ... I believe the relative ease — not to mention the lack of tangible cost — of software updates has created a cultural laziness within the software engineering community. ------------------------------------------------------------------------ Il 19/04/2019 09:02, Alberto Cammozzo ha scritto: Come accade che 346 persone muoiano di software. <https://spectrum.ieee.org/aerospace/aviation/how-the-boeing-737-max-disaster...> [...] It is astounding that no one who wrote the MCAS software for the 737 Max seems even to have raised the possibility of using multiple inputs, including the opposite angle-of-attack sensor, in the computer’s determination of an impending stall. As a lifetime member of the software development fraternity, I don’t know what toxic combination of inexperience, hubris, or lack of cultural understanding led to this mistake. But I do know that it’s indicative of a much deeper problem. The people who wrote the code for the original MCAS system were obviously terribly far out of their league and did not know it. How can they can implement a software fix, much less give us any comfort that the rest of the flight management software is reliable? So Boeing produced a dynamically unstable airframe, the 737 Max. That is big strike No. 1. Boeing then tried to mask the 737’s dynamic instability with a software system. Big strike No. 2. Finally, the software relied on systems known for their propensity to fail (angle-of-attack indicators) and did not appear to include even rudimentary provisions to cross-check the outputs of the angle-of-attack sensor against other sensors, or even the other angle-of-attack sensor. Big strike No. 3. None of the above should have passed muster. None of the above should have passed the “OK” pencil of the most junior engineering staff, much less a DER. That’s not a big strike. That’s a political, social, economic, and technical sin. [...] It is likely that MCAS, originally added in the spirit of increasing safety, has now killed more people than it could have ever saved. It doesn’t need to be “fixed” with more complexity, more software. It needs to be removed altogether. ------------------------------------------------------------------------ nexa mailing list nexa@server-nexa.polito.it https://server-nexa.polito.it/cgi-bin/mailman/listinfo/nexa -- EN ------------------------------------------------------------------------ Prof. Enrico Nardelli Dipartimento di Matematica - Universita' di Roma "Tor Vergata" Via della Ricerca Scientifica snc - 00133 Roma tel: +39 06 7259.4204 fax: +39 06 7259.4699 mobile: +39 335 590.2331 e-mail: nardelli@mat.uniroma2.it home page: http://www.mat.uniroma2.it/~nardelli blog: http://www.ilfattoquotidiano.it/blog/enardelli/ http://link-and-think.blogspot.it/ ------------------------------------------------------------------------