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  1. #1001
    Socio 2015 L'avatar di A345
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da Lukem3d Visualizza il messaggio
    Significa esattamente che sono pi pericolosi, avete idea dei tassi di incidenti degli aerei militari rispetto a quelli civili? Sugli aerei militari parliamo di cifre intorno al 2% dei velivoli che cadono, poi sono tutti dotati di seggiolino eiettabile e si riduce il tasso di morti, ma siamo.ad un livello del tutto inaccettabile per voli di linea .
    Un po' come il tasso di monoposto di F1 che si schiantano invece di "morire" di vecchiaia, inaccettabile!
    Fortuna che i piloti hanno il casco.

    Inviato dal mio VKY-L09 utilizzando Tapatalk
    To: MXP / LIN / BGY / VRN / BLQ / FRL / FCO / VIE / FRA / MUC / OTP / TSR / BEG / SVO / DME / OMS / AMS / LGW / EDI / NCL / CDG / LYS / LIL / BCN / CXJ / VLC / MAD / SVQ / LIS / YUL / MEX / CJS / GRU / CGH / POA / JDF/NTE/GIG/OPO/SCQ/LCG/LIG/CFE/ROV/REC/CNF/PLU/VAG/STN/WAW/POZ/CPH/STW/PRG/VKO/MAN/LHR/VIX/DXB/TPE/BRU/MSP/HUY/HAJ/SYD/IST/ICN/HKG/MEL
    With: V3/P8/AZ/AF/KL/OC/JJ/OS/YW/VO/LH/TP/S7/EZY/XG/ZS/IV/8I/AC/RG/WH/BA/G3/FR/AM/T4/LO/K2/SK/QI/SU/D9/OK/UN/BE/EK/EN/UX/W6/DL/WI/TK/CX/QR

  2. #1002
    Member L'avatar di OneShot
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da FlyKing Visualizza il messaggio
    La denominazione -8200 (ergo MAX-8 200 posti) era gi presente internamente dalla firma dellordine
    D'accordo FlyKing, lo sappiamo che l'ordine FR era per la versione -8 200, ma fino a ieri sulla fusoliera c'era scritto B737MAX, ora B737-8200.
    Si sempre detto su questo forum che il passeggero medio (leggasi il 95% dell'utenza, elevabile al 99% per quella FR) non ha questa cultura aeronautica fine da poter intuire il maquillage. Ergo, trattasi di mandrakata con annessa paraculata col fischio e senza.

  3. #1003
    Moderatore L'avatar di FlyKing
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da OneShot Visualizza il messaggio
    Si sempre detto su questo forum che il passeggero medio (leggasi il 95% dell'utenza, elevabile al 99% per quella FR) non ha questa cultura aeronautica fine da poter intuire il maquillage. Ergo, trattasi di mandrakata con annessa paraculata col fischio e senza.
    Non sono del tutto concorde.
    A causa degli incidenti, del clamore mediatico, del grounding e dello scaricabarile iniziale di Boeing, il brand “MAX” risulta ormai compromesso, cosa che avrebbe spinto comunque la dirigenza a cestinarlo. La macchina per continua ad essere prodotta e, presto o tardi, torner ad effettuare servizi pax, dunque si tratta solo di una mossa di marketing, non di una mandrakata, considerato che anche un minus habens pu estrarre il suo smartphone, aprire Google, digitare “Boeing 737-8200” e svelare l’arcano.
    Chiediti se quello che stai facendo oggi, ti avvicina al luogo dove vorresti essere domani.

  4. #1004

    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da FlyKing Visualizza il messaggio
    Non sono del tutto concorde.
    A causa degli incidenti, del clamore mediatico, del grounding e dello scaricabarile iniziale di Boeing, il brand “MAX” risulta ormai compromesso, cosa che avrebbe spinto comunque la dirigenza a cestinarlo. La macchina per continua ad essere prodotta e, presto o tardi, torner ad effettuare servizi pax, dunque si tratta solo di una mossa di marketing, non di una mandrakata, considerato che anche un minus habens pu estrarre il suo smartphone, aprire Google, digitare “Boeing 737-8200” e svelare l’arcano.
    Voi avete troppa fiducia nella GGente. Oppure avete la fortuna di frequentare solo persone normali, ovvero il 5% della popolazione. Ho amici/colleghi ai quali debbo spiegare quasi quotidianamente che se hanno un dubbio possono cercare risposta su Google. Attimo di stupore, e poi "Ah gi vero, Google. Grazie, sei troppo avanti!"

  5. #1005
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da cammellocane Visualizza il messaggio
    Voi avete troppa fiducia nella GGente. Oppure avete la fortuna di frequentare solo persone normali, ovvero il 5% della popolazione. Ho amici/colleghi ai quali debbo spiegare quasi quotidianamente che se hanno un dubbio possono cercare risposta su Google. Attimo di stupore, e poi "Ah gi vero, Google. Grazie, sei troppo avanti!"
    Aggiungerei giusto, a scanso di equivoci, di evitare domande come "la terra piatta ?", "i vaccini ti fanno crescere due teste ?" "posso tranquillamente spostare la mia residenza fiscale alle barbados senza rischi ?" e di rivolgersi a chi effettivamente competente in materia

  6. #1006

    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da FlyKing Visualizza il messaggio
    Non sono del tutto concorde.
    A causa degli incidenti, del clamore mediatico, del grounding e dello scaricabarile iniziale di Boeing, il brand MAX risulta ormai compromesso, cosa che avrebbe spinto comunque la dirigenza a cestinarlo. La macchina per continua ad essere prodotta e, presto o tardi, torner ad effettuare servizi pax, dunque si tratta solo di una mossa di marketing, non di una mandrakata, considerato che anche un minus habens pu estrarre il suo smartphone, aprire Google, digitare Boeing 737-8200 e svelare larcano.
    Per quanto comprensibile e necessario un abbandono del brand "Max" non potendo abbandonare gli aerei.
    A me "mandrakata" e "mossa di marketing" sembrano sinonimi.

  7. #1007

    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Penso sia giunto il momento di fare un breve riassunto di tecnica aeronautica per quanto riguarda le caratteristiche basiche di qualit di volo per quanto riguarda la stabilit. Anche se pu sembrare ripetitivo, credo che possa essere ancora utile non solo a coloro che un po conoscono la materia ma anche a coloro che, per formazione, non hanno mai avvicinato queste tematiche.

    STABILITA STATICA : la tendenza di un aereo, trimmato in una certa condizione, di ritornare alla condizione trimmata quando viene da questo discostato (per una azione del pilota, per turbolenza, etc). Non si considera il tempo necessario a tornare alla condizione iniziale, ma solo la tendenza.

    STABILITA DINAMICA : la caratteristica di un aereo, trimmato in una certa condizione iniziale , di ritornare alla posizione iniziale stessa, quando discostato da essa ,e quando dinamicamente stabile , smorzando nel tempo le oscillazioni (se presenti).


    In ordine :

    STABILITA STATICA
    Nonostante quello che alcuni possano pensare, stabilit statica a comandi fissi ed a comandi liberi nulla hanno a che vedere con il fatto che la mano del pilota impugni o meno il volantino .

    Comandi fissi : partendo da una posizione di trim, si sposta il comando di incrementi, per verificare il risultato . Per la stabilit longitudinale a comandi fissi, per ogni 10 nodi di aumento di velocit si vuole verificare che lelevatore si sposti linearmente TED (Trailing Edge Down, ovvero a picchiare). Stessa cosa a cabrare.
    Se per incrementare 10 nodi necessario un elevatore di 2 TED, si vuole che per incremento di 20 nodi lelevatore necessario sia 3 TED. La posizione del baricentro importante : se troppo arretrato, potrebbe succedere che con uno spostamento di 2, si riescono a trimmare tante velocit (al limite tutte ), ovvero laereo sarebbe in equilibrio a tutte le velocit senza dare una retroazione tattile al pilota. Si parla in questo caso di stabilit a comandi fissi neutra, e la relativa posizione del baricentro si chiama punto neutro a comandi fissi .

    Comandi liberi : non si guarda pi alla posizione dellelevatore ma alla forza sviluppata dal pilota per mantenere la condizione al di fuori di quella di trim ; se laereo trimmato a 250 kts (quindi forza nulla), si desidera che per mantenere laereo a 270 kts siano necessari 3 kg a spingere , e per mantenerlo a 290 kts siano necessari (ad es.) 5 kg a spingere; in questo caso non interessa la posizione della superficie, bens solo la forza.
    Ed qui che sta uno dei pi grandi fraintendimenti ! Ovvero : la stabilit a comandi liberi concerne gli sforzi effettuati dal pilota e non ha niente a che fare con il comportamento dellaereo quando i comandi sono liberi !! A parit di aereo, a mano a mano che arretra il baricentro, la stabilit a comandi liberi diminuisce (ovvero, diminuiscono gli sforzi per ottenere una medesima variazione di velocit ).Laddove la forza la medesima per mantenere laereo a tutte le velocit, il relativo baricentro si trova nel punto neutro a comandi liberi.

    Spostando il baricentro verso la coda, si incontra prima il punto neutro a comandi liberi, e poi il punto neutro a comandi fissi.

    Un aereo con stabilit neutra a comandi liberi ancora pilotabile (es : molti aerei acrobatici posseggono gradienti di forza quasi nulli attorno alla posizione di trim, quindi stabilit statica a comandi liberi quasi nulla), in quanto pur non fornendo al pilota una retroazione tattile sugli gli sforzi di barra , comunque riesce a fornirgli una indicazione tattile della posizione della barra , mentre un aereo con stabilit neutra a comandi bloccati (posizioni) impilotabile , perch ad ogni posizione della barra corrisponderebbero infinite velocit di volo di equilibrio , senza dare al pilota alcuna retroazione tattile sulla posizione della barra

    STABILITA DINAMICA
    Se un aereo staticamente stabile, tender a tornare alla posizione iniziale qualora discostato da essa.
    Nel caso della stabilit dinamica, levoluzione della velocit o dellangolo di incidenza in funzione del tempo importante. Se laereo oscilla con ampiezze sempre minori, si dice che stabile dinamicamente, se loscillazione prosegue senza aumentare o diminuire, laereo dinamicamente neutro, e se invece loscillazione aumenta si dice che laereo dinamicamente instabile.

    Per il caso dellasse longitudinale, esistono due tipi di oscillazioni : quella di lungo periodo (chiamata fugoide), nella quale langolo dincidenza quasi costante, ma laereo cabra e picchia lentamente ed contemporaneamente aumenta e diminuisce la velocit e la quota (in controfase con la velocit) . Il periodo dell onda grossomodo un ottavo (1/8) della velocit trimmata espressa in km/h.
    Quella di breve periodo (SPO= short period oscillation) invece una rapida oscillazione dellangolo di incidenza a velocit costante, senza escursioni di quota. E normalmente rapidamente smorzata, e quasi invisibile al pilota. Quando non smorzata, distruttiva ( non centra nulla con il flutter, e non centra nulla con le PIO, Pilot Induced Oscillation).

    Tutto quanto sopra pu dipendere molto dalla velocit di trim iniziale : se laereo trimmato ad alta velocit, laddove quindi i fenomeni sono abbastanza lineari, si pu avere un comportamento adeguato.
    Se si trimma a bassa velocit e con flaps abbassati , o nei pressi del Mach Massimo Operativo (MMO), , potrebbero aversi caratteristiche inadeguate , dovute ad esempio a diversa interazioni fra ala e stabilizzatore, oppure nacelle motori ed ala .

    Tipica la riduzione della stabilit statica a comandi liberi (sforzi bassissimi per accelerare laereo) che si incontra nei pressi del Mach massimo su praticamente tutti gli aerei a getto !!! Come viene curata questa caratteristica negativa ? Con il Mach trim, che sposta lo stabilizzatore a cabrare per aumentare sforzo e spostamento della barra qualora il pilota continuasse a spingere fornendo quindi un feedback tattile che gli indica che si sta facendo qualcosa di sbagliato.

    Oppure , con lormai famoso MAX, gli alti angoli di incidenza possono indurre un portanza davanti al CG (causati da nacelle pi grosse) che diminuisce la stabilit statica a comandi liberi (ovvero sforzi per ridurre la velocit), diminuendo il feedback al pilota che lo avviserebbe di tirare meno la barra.

    Come ha fatto la Boeing a correggere questa caratteristica negativa ? Ha fatto come con il Mach Trim,
    ma al contrario, ovvero trimmando a picchiare ; tuttavia, sembra che abbia usato una logica diversa, tale per cui una singola avaria nel sistema abbia avuto effetti catastrofici.

    Gli aerei instabili possono per essere pilotabili ?? Certo che s ! Ma non dal solo pilota umano !
    Ci deve essere un pilota elettronico che sente le tendenze e le contrasta, direttamente o tramite feedback di sforzo o spostamento ai comandi (barra e pedaliera) . Tipicamente , il ductch-roll una oscillazione combinata sul rollio e limbardata che ,ad alte quote ed alti mach (dove gli smorzamenti sugli assi laterale e direzionale sono minori), spesso incontrollabile dal pilota-con il risultato che laereo continuerebbe ad avere oscillazioni combinate quanto meno fastidiosissime per il passeggero. Come viene curata ? Con lo yaw-damper (smorzatore di imbardata), che percepisce le velocit di imbardata e le tendenze prima ancora del pilota, ed agisce direttamente sul timone (o su superfici dedicate, non visibili al pilota) ; paragonabile ad un copilota silenzioso e molto pi bravo del pilota (se mai fosse possibile) nel risolvere un solo problema , loscillazione latero-direzionale , appunto


    Spero di essere stato utile nel fornire qualche chiarimento sui vari tipi di stabilit degli aerei

  8. #1008

    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Grazie SOYUZ per questo interessantissimo post.
    Ciao

  9. #1009
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Come diceva il mio istruttore di Aeromodellismo, modello picchiato modello salvato... modello cabrato modello schiantato.... le forze cabranti sono sempre difficili da controllare...

    *** in aggiornamento ***

  10. #1010
    Junior Member L'avatar di marksimon
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Grazie SOYUZ anche da parte mia.
    Tutto molto interessante, me lo rilegger con calma perch per capirlo ci impiegher parecchio.

    Ciao
    Marco

  11. #1011
    Senior Member L'avatar di TW 843
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    EASA alerts Airbus A321neo operators over excessive pitch issue
    The European Union Aviation Safety Agency (EASA) has alerted operators of the Airbus A321neo of a potential excessive pitch problem. The issue, as many aviation professionals have noted, is similar to the one that Boeings MCAS software on the 737 MAX was developed to address.

    Airbus has issued a temporary revision to its A321neo flight manuals in order to prevent the aircraft from possibly reaching excessive pitch attitudes, according to a report by FlightGlobal. The revisions have been necessitated after analysis of the aircrafts elevator and aileron computer, the EASA disclosed in an Airworthiness Directive (AD) on July 17, 2019.

    The regulator stated that excessive pitch attitude could occur in certain conditions and during specific maneuvers, warning that the condition could result in reduced control of the aircraft. As a safety measure, EASA has ordered A321neo operators to update the flight manuals subsequently, within 30 days of the AD.

    Airlinerwatch points out the MCAS (Maneuvering Characteristics Augmentation System) installed on the MAX was also intended to prevent excessive pitch of the aircraft. The software would push down the nose of the aircraft if the AOA (Angle of Attack) sensor detected too steep of a pitch.

    However, according to Air Insight, Airbus existing fly-by-wire system is more extensive than on the MAX jets, which should ensure safe operation of the A321neo once the ordered procedure is carried out. It is still unknown whether a software modification will be needed for the type.

    The A321neo entered into service in May 2017, with former Virgin America (now Alaska Airlines), the same time as the Boeing 737 MAX did. A member of the Airbus A320 Family of aircraft, the A321neo is the new-generation re-engined variant of the A321. The narrow-body jet has a maximum range of 7,400 km (4,000 nm) and is capable of seating up to 220 passengers in a typical two-class configuration.

  12. #1012

    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Chi controlla i controllori? Ahiaiai FAA..

    The Roots of Boeing’s 737 Max Crisis: A Regulator Relaxes Its Oversight

    By Natalie Kitroeff, David Gelles and Jack Nicas
    July 27, 2019
    SEATTLE — In the days after the first crash of Boeing’s 737 Max, engineers at the Federal Aviation Administration came to a troubling realization: They didn’t fully understand the automated system that helped send the plane into a nose-dive, killing everyone on board.

    Engineers at the agency scoured their files for information about the system designed to help avoid stalls. They didn’t find much. Regulators had never independently assessed the risks of the dangerous software known as MCAS when they approved the plane in 2017.

    More than a dozen current and former employees at the F.A.A. and Boeing who spoke with The New York Times described a broken regulatory process that effectively neutered the oversight authority of the agency.

    The regulator had been passing off routine tasks to manufacturers for years, with the goal of freeing up specialists to focus on the most important safety concerns. But on the Max, the regulator handed nearly complete control to Boeing, leaving some key agency officials in the dark about important systems like MCAS, according to the current and former employees.

    While the agency’s flawed oversight of the Boeing 737 Max has attracted much scrutiny since the first crash in October and a second one in March, a Times investigation revealed previously unreported details about weaknesses in the regulatory process that compromised the safety of the plane.

    The company performed its own assessments of the system, which were not stress-tested by the regulator. Turnover at the agency left two relatively inexperienced engineers overseeing Boeing’s early work on the system.

    The F.A.A. eventually handed over responsibility for approval of MCAS to the manufacturer. After that, Boeing didn’t have to share the details of the system with the two agency engineers. They weren’t aware of its intricacies, according to two people with knowledge of the matter.

    Late in the development of the Max, Boeing decided to expand the use of MCAS, to ensure the plane flew smoothly. The new, riskier version relied on a single sensor and could push down the nose of the plane by a much larger amount.

    Boeing did not submit a formal review of MCAS after the overhaul. It wasn’t required by F.A.A. rules. An engineering test pilot at the regulator knew about the changes, according to an agency official. But his job was to evaluate the way the plane flew, not to determine the safety of the system.

    The agency ultimately certified the jet as safe, required little training for pilots and allowed the plane to keep flying until a second deadly Max crash, less than five months after the first.

    The plane remains grounded as regulators await a fix from Boeing. If the ban persists much longer, Boeing said this past week that it could be forced to halt production.

    The F.A.A. and Boeing have defended the plane’s certification, saying they followed proper procedures and adhered to the highest standards.

    “The agency’s certification processes are well-established and have consistently produced safe aircraft designs,” the regulator said in a statement Friday. “The 737 Max certification program involved 110,000 hours of work on the part of F.A.A. personnel, including flying or supporting 297 test flights.”

    Boeing said “the F.A.A.’s rigor and regulatory leadership has driven ever-increasing levels of safety over the decades,” adding that “the 737 Max met the F.A.A.’s stringent standards and requirements as it was certified through the F.A.A.’s processes.”

    [If you have worked at Boeing or the F.A.A. and want to discuss your experience, contact The Times confidentially here.]


    Federal prosecutors and lawmakers are now investigating whether the regulatory process is fundamentally flawed. As planes become more technologically advanced, the rules, even when they are followed, may not be enough to ensure safety. The new software played a role in both disasters, involving Lion Air and Ethiopian Airlines, which together killed 346 people.

    “Did MCAS get the attention it needed? That’s one of the things we’re looking at,” said Chris Hart, the former chairman of the National Transportation Safety Board, who is now leading a multiagency task force investigating how the Max was approved. “As it evolved from a less robust system to a more powerful system, were the certifiers aware of the changes?”

    Boeing needed the approval process on the Max to go swiftly. Months behind its rival Airbus, the company was racing to finish the plane, a more fuel-efficient version of its best-selling 737.

    The regulator’s hands-off approach was pivotal. At crucial moments in the Max’s development, the agency operated in the background, mainly monitoring Boeing’s progress and checking paperwork. The nation’s largest aerospace manufacturer, Boeing was treated as a client, with F.A.A. officials making decisions based on the company’s deadlines and budget.

    It has long been a cozy relationship. Top agency officials have shuffled between the government and the industry.

    During the Max certification, senior leaders at the F.A.A. sometimes overruled their own staff members’ recommendations after Boeing pushed back. For safety reasons, many agency engineers wanted Boeing to redesign a pair of cables, part of a major system unrelated to MCAS. The company resisted, and F.A.A. managers took Boeing’s side, according to internal agency documents.

    After the crash of the Lion Air plane last October, F.A.A. engineers were shocked to discover they didn’t have a complete analysis of MCAS. The safety review in their files didn’t mention that the system could aggressively push down the nose of the plane and trigger repeatedly, making it difficult to regain control of the aircraft, as it did on the doomed Lion Air flight.

    Despite their hazy understanding of the system, F.A.A. officials decided against grounding the 737 Max. Instead, they published a notice reminding pilots of existing emergency procedures.

    The notice didn’t describe how MCAS worked. At the last minute, an F.A.A. manager told agency engineers to remove the only mention of the system, according to internal agency documents and two people with knowledge of the matter. Instead, airlines learned about it from Boeing.

    ‘He really wanted abdication.’
    The F.A.A. department that oversaw the Max development had such a singular focus that it was named after the company: The Boeing Aviation Safety Oversight Office.

    Many F.A.A. veterans came to see the department, created in 2009, as a symbol of the agency’s close relationship with the manufacturer. The top official in Seattle at the time, Ali Bahrami, had a tough time persuading employees to join, according to three current and former employees.

    Some engineers believed that Mr. Bahrami had installed managers in the office who would defer to Boeing. “He didn’t put enough checks and balances in the system,” Mike McRae, a former F.A.A. engineer, said of Mr. Bahrami. “He really wanted abdication. He didn’t want delegation.”

    Before the certification of the Max began, Mr. Bahrami called a group of F.A.A. engineers into his office, the current and former employees said, and asked some of them to join the group. Many didn’t want to change jobs, according to a complaint filed by the National Air Traffic Controllers Association, the union representing F.A.A. engineers.

    “I got dragged kicking and screaming,” said Richard Reed, a former systems engineer at the F.A.A. Mr. Reed said he had just left surgery when agency officials called to ask whether he would work in the office. “I always claimed that I was on drugs when I said ‘yes.’”

    The F.A.A. said in a statement that Mr. Bahrami “dedicated his career to the advancement of aviation safety in both the private and public sectors.”

    For decades, the F.A.A. relied on engineers inside Boeing to help certify aircraft. But after intense lobbying by industry, the agency adopted rules in 2005 that would give manufacturers like Boeing even more control. Previously, the agency selected the company engineers to work on its behalf; under the new regulations, Boeing could choose them.

    Many of the agency’s top leaders embraced the approach. It would allow the F.A.A. to certify planes more efficiently and stretch its limited resources. The regulator had also been finding it harder to compete for talented engineers, their government salaries unable to keep up with the going rates in the industry.

    For Boeing, the changes meant shedding a layer of bureaucracy. “The process was working well,” said Tom Heineman, a retired Boeing engineer who worked on the Max. “The F.A.A. was delegating more of the work and the review and the oversight to the manufacturers than it used to.”

    But some F.A.A. engineers were concerned that they were no longer able to effectively monitor what was happening inside Boeing. In a PowerPoint presentation to agency managers in 2016, union representatives raised concerns about a “brain drain” and the “inability to hire and retain qualified personnel.”

    By 2018, the F.A.A. was letting the company certify 96 percent of its own work, according to an agency official.

    Nicole Potter, an F.A.A. propulsion and fuel systems engineer who worked on the Max, said supervisors repeatedly asked her to give up the right to approve safety documents. She often had to fight to keep the work.

    “Leadership was targeting a high level of delegation,” Ms. Potter said. When F.A.A. employees didn’t have time to approve a critical document, she said, “managers could delegate it back to Boeing.”

    It was a process Mr. Bahrami championed to lawmakers. After spending more than two decades at the F.A.A., he left the agency in 2013 and took a job at the Aerospace Industries Association, a trade group that represents Boeing and other manufacturers.

    “We urge the F.A.A. to allow maximum use of delegation,” Mr. Bahrami told Congress in his new lobbying role, arguing it would help American manufacturers compete.

    In 2017, Mr. Bahrami returned to the F.A.A. as the head of safety.

    An internal battle at the F.A.A.
    With Boeing taking more control, F.A.A. engineers found they had little power, even when they did raise concerns.

    Early on, engineers at the F.A.A. discovered a problem with one of the most important new features of the Max: its engines. The Max, the latest version of the 50-year-old 737, featured more fuel-efficient engines, with a larger fan and a high-pressure turbine. But the bigger, more complex engines could do more damage if they broke apart midair.

    The F.A.A. engineers were particularly concerned about pieces hitting the cables that control the rudder, according to five people with knowledge of the matter and internal agency documents. A cable severed during takeoff would make it difficult for pilots to regain control, potentially bringing down the jet.

    The F.A.A. engineers suggested a couple solutions, three of the people said. The company could add a second set of cables or install a computerized system for controlling the rudder.

    Boeing did not want to make a change, according to internal F.A.A. documents reviewed by The Times. A redesign could have caused delays. Company engineers argued that it was unlikely that an engine would break apart and shrapnel would hit the rudder cable.

    Most of the F.A.A. engineers working on the issue insisted the change was necessary for safety reasons, according to internal agency emails and documents. But their supervisors balked. In a July 2015 meeting, Jeff Duven, who replaced Mr. Bahrami as the head of the F.A.A.’s Seattle operation, sided with Boeing, said two current employees at the agency.

    F.A.A. managers conceded that the Max “does not meet” agency guidelines “for protecting flight controls,” according to an agency document. But in another document, they added that they had to consider whether any requested changes would interfere with Boeing’s timeline. The managers wrote that it would be “impractical at this late point in the program,” for the company to resolve the issue. Mr. Duven at the F.A.A. also said the decision was based on the safety record of the plane.

    Engineers at the agency were demoralized, the two agency employees said. One engineer submitted an anonymous complaint to an internal F.A.A. safety board, which was reviewed by The Times.

    “During meetings regarding this issue the cost to Boeing to upgrade the design was discussed,” the engineer wrote. “The comment was made that there may be better places for Boeing to spend their safety dollars.”

    An F.A.A. panel investigated the complaint. It found managers siding with Boeing had created “an environment of mistrust that hampers the ability of the agency to work effectively,” the panel said in a 2017 report, which was reviewed by The Times. The panel cautioned against allowing Boeing to handle this kind of approval, saying “the company has a vested interest in minimizing costs and schedule impact.”

    By then, the panel’s findings were moot. Managers at the agency had already given Boeing the right to approve the cables, and they were installed on the Max.

    Playing down risks
    In the middle of the Max’s development, two of the most seasoned engineers in the F.A.A.’s Boeing office left.

    The engineers, who had a combined 50 years of experience, had joined the office at its creation, taking on responsibility for flight control systems, including MCAS. But they both grew frustrated with the work, which they saw as mostly paper pushing, according to two people with knowledge of the staff changes.

    In their place, the F.A.A. appointed an engineer who had little experience in flight controls, and a new hire who had gotten his master’s degree three years earlier. People who worked with the two engineers said they seemed ill-equipped to identify any problems in a complex system like MCAS.

    And Boeing played down the importance of MCAS from the outset.

    An early review by the company didn’t consider the system risky, and it didn’t prompt additional scrutiny from the F.A.A. engineers, according to two agency officials. The review described a system that would activate only in rare situations, when a plane was making a sharp turn at high speeds.

    The F.A.A. engineers who had been overseeing MCAS never received another safety assessment. As Boeing raced to finish the Max in 2016, agency managers gave the company the power to approve a batch of safety assessments — some of the most important documents in any certification. They believed the issues were low risk.

    One of the managers, Julie Alger, delegated the review of MCAS. Previously, the F.A.A. had the final say over the system.

    The F.A.A. said that decision reflected the consensus of the team.

    Boeing was in the middle of overhauling MCAS. To help pilots control the plane and avoid a stall, the company allowed MCAS to trigger at low speeds, rather than just at high speeds. The overhauled version would move the stabilizer by as much as 2.5 degrees each time it triggered, significantly pushing down the nose of the plane. The earlier version moved the stabilizer by 0.6 degrees.

    When company engineers analyzed the change, they figured that the system had not become any riskier, according to two people familiar with Boeing’s discussions on the matter. They assumed that pilots would respond to a malfunction in three seconds, quickly bringing the nose of the plane back up. In their view, any problems would be less dangerous at low speeds.

    So the company never submitted an updated safety assessment of those changes to the agency. In several briefings in 2016, an F.A.A. test pilot learned the details of the system from Boeing. But the two F.A.A. engineers didn’t understand that MCAS could move the tail as much as 2.5 degrees, according to two people familiar with their thinking.

    Under the impression the system was insignificant, officials didn’t require Boeing to tell pilots about MCAS. When the company asked to remove mention of MCAS from the pilot’s manual, the agency agreed. The F.A.A. also did not mention the software in 30 pages of detailed descriptions noting differences between the Max and the previous iteration of the 737.

    Days after the Lion Air crash, the agency invited Boeing executives to the F.A.A.’s Seattle headquarters, according to two people with knowledge of the matter. The officials sat incredulous as Boeing executives explained details about the system that they didn’t know.

    In the middle of the conversation, an F.A.A. employee, one of the people said, interrupted to ask a question on the minds of several agency engineers: Why hadn’t Boeing updated the safety analysis of a system that had become so dangerous?
    https://www.nytimes.com/2019/07/27/b...7-max-faa.html

  13. #1013
    Member L'avatar di OneShot
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    China Southern cancella l'ordine dei rimanenti 64 MAX.

  14. #1014
    Junior Member L'avatar di Senator
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    A former Boeing engineer has told the BBC's Panorama programme that work on the production line of the 737 Max plane was not adequately funded.
    The aircraft is currently grounded after two crashes which killed 346 people.
    The 737 Max is the company's fastest selling plane and has earned the company billions of dollars in sales.
    Boeing denies the claims and says it's committed to making the 737 Max one of the safest aircraft ever to fly.


    Media captionBoeing 737 Max: Work on production line "not adequately funded"
    Adam Dickson worked at Boeing for 30 years and led a team of engineers who worked on the 737 Max. He said they were under constant pressure to keep costs down.
    "Certainly what I saw was a lack of sufficient resources to do the job in its entirety," he says.
    "The culture was very cost centred, incredibly pressurised. Engineers were given targets to get certain amount of cost out of the aeroplane."
    Adam Dickson
    Image caption
    Adam Dickson worked for three decades at Boeing
    Mr Dickson said engineers were under pressure to downplay new features on the 737 Max.
    He said by classifying them as minor rather than major changes, Boeing would face less scrutiny from the US regulator, the Federal Aviation Administration.
    "The goal was to show that those differences were so similar to the previous design that it would not require a major design classification in the certification process. There was a lot of interest and pressure on the certification and analysis engineers in particular, to look at any changes to the Max as minor changes."
    Boeing 737 Max
    He said that downplaying the changes reduced scrutiny in a way that could impact safety. Now even his own family have fears about the plane's safety.
    "My family won't fly on a 737 Max. It's frightening to see such a major incident because of a system that didn't function properly or accurately."
    Boeing and the battle over blame
    What went wrong inside Boeing's cockpit?
    Boeing said its former engineer's comments were incorrect.
    "We did not cut corners or push the 737 Max out before it was ready," it said.
    "We have always held true to our values of safety, quality and integrity and those values are complementary and mutually reinforcing with productivity and company performance."
    Boeing cockpit
    Image caption
    Boeing says that safety is one of its values
    Passengers first flew on the 737 Max in 2017, but airlines have been making advance purchases since the plane was first marketed in 2011
    Five thousand have been ordered - making it the fastest-selling plane in Boeing's history.
    Some of the money from those sales has been used to fund big pay-outs for company executives and shareholders.
    'Supercharge'
    Since 2013, Boeing has paid $17bn (13.74bn) in dividends to shareholders and has spent a further $43bn buying its own shares - a spending spree that has helped Boeing treble its share price in just five years.
    Chief executive Dennis Muilenburg has also been paid more than $70m.
    Economist William Lazonick
    Image caption
    Economist William Lazonick says senior management were too focused on making money.
    Critics have accused Boeing of paying more attention to the stock market than the safety of its passengers.
    Economist William Lazonick said senior management were too focused on making money.
    "If you supercharge the incentives of top executives and tell them that their job is to get the stock price up, they're not going to pay the kind of attention they need to pay to ensuring they produce a safe plane," he said.
    Boeing HQ
    Boeing said it "follows a balanced cash deployment strategy that ensures investment in our core businesses and workforce, returns value to shareholders and maintains our strong balance sheet and credit rating".
    The 737 Max has been grounded since March and there is currently no sign of regulators allowing the plane back in the skies.
    Boeing warns it may halt 737 Max production
    Boeing takes $5bn hit to cover 737 Max crisis
    Boeing has been trying to fix the software that forced the aircraft in Indonesia and Ethiopia down.
    MCAS was designed to operate when the plane was flying at a steep, nose-up angle - and would automatically attempt to move the nose downwards.
    It was meant to make the controls feel more predictable and familiar to pilots who were used to older versions of the 737.


    Media captionThe MCAS system explained
    But pilots didn't know about MCAS because it wasn't included in training materials or the 1,600-page manual for the Max.
    Boeing's system also had a fatal flaw - it used a single sensor to work out the angle the plane was flying at.
    On both the Indonesian and Ethiopian flights, that sensor stopped working properly. This resulted in MCAS forcing the aircraft downwards even though they were already on the correct course.
    The pilots struggled to regain control, because MCAS was designed to kick back in every few seconds. The Indonesian plane was forced down more than 20 times before it crashed.
    'Complicated'
    Boeing said it wasn't relying on the single sensor, because the pilots were there as back up. It said there was a way to override MCAS - a standard procedure that pilots should have known about from flying the old 737.
    The company has said the pilots didn't completely follow the correct operating procedures when things went wrong.
    But 737 pilots like Chris Brady say it is wrong to blame the pilots.
    Boeing production line
    "If you're going to design and certify an airliner with such a complicated, obscure failure mode as happened to that crew, it's no wonder that your average crew aren't able to deal with it," he said.
    Boeing said it is focusing on implementing the software update, finalising pilot training and rebuilding trust with customers.
    "Boeing truly regrets the loss of life and will continue to work with communities, customers and the aviation industry to help with the healing process," it said.
    "In any accident we must learn from what happened. It's also important to avoid speculating ahead of the final investigative reports."
    Watch BBC Panorama: Boeing's Killer Planes, on 29 July at 8.30pm on BBC One.

  15. #1015
    Junior Member L'avatar di Senator
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba


  16. #1016

    Predefinito 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Adam non c andato leggero!
    Se anche solo la met di quanto ha detto si rivelasse fondato, da brividi.
    On ne voit bien quavec le cur. Lessentiel est invisible pour les yeux (Antoine de Saint-Exupry)

  17. #1017
    Member L'avatar di Marilson
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Lavoro nell'industria biomedicale con produttore e seguo, seppur marginalmente, sviluppo e certificazione. L'autocertificazione e' prevista solo per dispositivi medici di classe I, come ad esempio un materasso di un letto di ospedale. Per tutto il resto si deve procedere con certificazione tramite organismo certificante terzo e sono procedure lunghe e costose. In generale, tutte le apparecchiature diagnostiche/terapeutiche devono essere certificate. E non esiste il concetto che se il nuovo modello e' simile al precedente, si puo' autocertificare. Tutto deve essere fatto da zero. E' come se un'azienda x produce un ventilatore per anestesia e, sostenendo sia la versione aggiornata del precedente, chiederebbe di autocertificare. Le riderebbero in faccia. Quello che ho letto sopra e' agghiacciante, qualora fosse vero.

  18. #1018
    Senior Member L'avatar di East End Ave
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da Seaking Visualizza il messaggio
    Adam non c andato leggero!
    Se anche solo la met di quanto ha detto si rivelasse fondato, da brividi.
    Spero che per l'altra eventuale meta' abbia un buon avvocato; non credo che Boeing se ne possa stare li' a far pippa e sarebbe anche bello che si correlassero certe denunce pubbliche, tantopiu' rilasciate alla stampa, con documentazione probante. Cosi' son buoni tutti.
    A meno che non sia caduto in disgrazia e viva in una baracca nei sobborghi di Detroit.

  19. #1019
    Senior Member L'avatar di East End Ave
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Intanto China Southern cancella ordine per 64 Max; non la vedo davvero bene per i nostri amici di Everett...

  20. #1020

    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da East End Ave Visualizza il messaggio
    Spero che per l'altra eventuale meta' abbia un buon avvocato; non credo che Boeing se ne possa stare li' a far pippa e sarebbe anche bello che si correlassero certe denunce pubbliche, tantopiu' rilasciate alla stampa, con documentazione probante. Cosi' son buoni tutti.
    A meno che non sia caduto in disgrazia e viva in una baracca nei sobborghi di Detroit.
    Se BBC ha pubblicato questo articolo qualche carta a supporto lavr certamente vista.
    Inoltre non credo che un ex dipendente inizi una battaglia del genere senza avere qualcosa di solido in mano.
    On ne voit bien quavec le cur. Lessentiel est invisible pour les yeux (Antoine de Saint-Exupry)

  21. #1021
    Socio 2015 L'avatar di A345
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da East End Ave Visualizza il messaggio
    Intanto China Southern cancella ordine per 64 Max; non la vedo davvero bene per i nostri amici di Everett...
    Se va avanti cos, tra i costi per coprire i noleggi a sostituzione degli aerei a terra e quelli non consegnati, eventuali penali e gli ordini cancellati, le perdite avranno ben pi di 9 zeri!
    To: MXP / LIN / BGY / VRN / BLQ / FRL / FCO / VIE / FRA / MUC / OTP / TSR / BEG / SVO / DME / OMS / AMS / LGW / EDI / NCL / CDG / LYS / LIL / BCN / CXJ / VLC / MAD / SVQ / LIS / YUL / MEX / CJS / GRU / CGH / POA / JDF/NTE/GIG/OPO/SCQ/LCG/LIG/CFE/ROV/REC/CNF/PLU/VAG/STN/WAW/POZ/CPH/STW/PRG/VKO/MAN/LHR/VIX/DXB/TPE/BRU/MSP/HUY/HAJ/SYD/IST/ICN/HKG/MEL
    With: V3/P8/AZ/AF/KL/OC/JJ/OS/YW/VO/LH/TP/S7/EZY/XG/ZS/IV/8I/AC/RG/WH/BA/G3/FR/AM/T4/LO/K2/SK/QI/SU/D9/OK/UN/BE/EK/EN/UX/W6/DL/WI/TK/CX/QR

  22. #1022

    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Ma qualcuno mi pu brevemente spiegare perch le aziende negli ultimi anni hanno ricomprato le proprie azioni, invece che investire? Quali sono i vantaggi?

  23. #1023

    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da Casa Visualizza il messaggio
    Ma qualcuno mi pu brevemente spiegare perch le aziende negli ultimi anni hanno ricomprato le proprie azioni, invece che investire? Quali sono i vantaggi?
    In questo modo fai salire il valore di ogni singola azione posseduta dagli investitori. Il valore sale perch a parit di valore della societ, ci sono meno azioni in circolazione. E' un alternativa al dividendo per distribuire valore agli azionisti, il perch venga scelta questa strada rispetto ad un altra, non lo so con certezza, almeno con la legislazione italiana subentra anche un fattore fiscale, se ho una minusvalenza non la posso compensare con il guadagno dovuto ai dividendi, mentre la posso compensare con un aumento del valore delle azioni (quando le vendo). Non so se questa modalit di tassare l'utile sia diffusa anche in altri paesi.

  24. #1024
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    Quote Originariamente inviato da A345 Visualizza il messaggio
    Se va avanti cos, tra i costi per coprire i noleggi a sostituzione degli aerei a terra e quelli non consegnati, eventuali penali e gli ordini cancellati, le perdite avranno ben pi di 9 zeri!
    Scusatemi se intervengo.
    Qualche giorno fa in Belgio, ho visto degli A320 della Tui Airlines Belgio, notoriamente la Tui A. Belgio ha una flotta di B737-800, da planespotters ho visto che sono fermi al prato 4 B737 Max, sostituiti con noleggio di 4 A320 della SmartLynx Estonia.
    Ora la domanda, , ma questi noleggi di aerei e piloti la Tui manda il conto a Boeing??
    Anche le altre compagnie, costrette a noleggiare aerei non propri causa blocco dei MAX.

    Grazie

  25. #1025
    Senior Member L'avatar di TW 843
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    Predefinito Re: 737 MAX 8 Ethiopian si schianta subito dopo il decollo da Addis Abeba

    How Spirit Is Dealing with Max Grounding

    The top executive of Boeing’s largest 737 Max supplier, Spirit AeroSystems, provided more detail about how it’s responding to the airplane’s grounding during the company's second-quarter 2019 earnings call this week. Spirit CEO Tom Gentile explained that the supplier, which manufactures the Max’s fuselage and other structures, continues to build the fuselages at a rate of 52 a month and expects that to remain unchanged through 2020.

    Completed fuselages are stored for between 10 and 20 days before Spirit ships them by rail from Wichita to Boeing’s 737 factory in Renton, Washington. So far, Spirit has stored and shipped 130 of them, and currently has 35 stored outside at nearby Air Capital Flight Line. Fuselages are wrapped in a three-layer process to protect them from the weather, a procedure that takes four hours.

    To keep costs in check, Spirit has undertaken a number of measures, including four-day workweeks for about 6,000 workers; 10-day furloughs for other workers as well as senior leaders; and a voluntary retirement program in which nearly 200 participated. It also reduced contract workers and cut overtime by half.

    Should a Max return-to-service be delayed beyond 2019, “we have been doing that scenario planning and we are going to be prepared to respond to whatever [Boeing does],” Gentile added. “We have looked at slowing down production. We have looked at doing some temporary pauses in production.”

    AIN

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