Precipitato un B737 Max 8 di Ethiopian

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belumosi
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda belumosi » sab 04 mag 2019, 12:26:23

mxp98 ha scritto:Nessuno spam, anzi grazie per gli aggiornamenti e tutti i retroscena.

Quoto e grazie anche da parte mia.
malpensante ha scritto:Non ricordo di aver mai letto niente di più ipocrita in vita mia. Persino Cesare Battisti, che peraltro ha sulla coscienza solo qualche morto e non centinaia, ultimamente mi sembra più serio.
E' una linea obbligata, adesso non possono fare altro che minimizzare e nel contempo risolvere i problemi.
E pensare che sarebbero stati sufficienti provvedimenti limitati e non particolarmente costosi per evitare tutto questo casino e salvare la vita di 346 disgraziati.

kco
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda kco » sab 04 mag 2019, 13:40:00

Questo articolo spiega bene come il sistema Airbus differisca sostanzialmente

The consequences of spurious sensor readings have affected Airbus as well as Boeing - and unexpected incidents illustrate the difficulties designers and regulators face in predicting and avoiding unintended aircraft behaviour.

Grounding of the Boeing 737 Max followed two fatal accidents involving unreliable angle-of-attack information and persistent automatic nose-down response from a new pitch-control system.

Airbus types have experienced serious issues that appear superficially similar to those affecting the Max. However, some crucial considerations, centred on the Airbus design and time in service, have resulted in far less disruptive regulatory intervention.

Shortly after an Eva Air A330's departure in 2012 it suffered an angle-of-attack sensor jam, at 5°, as it climbed through 11,000ft. Although the angle was shallow, angle-of-attack margins become narrower, increasing the risk of stall, as an aircraft climbs and its Mach number increases.

When the A330 reached an altitude at which this false angle-of-attack data exceeded a critical threshold, the aircraft's stall-protection mechanism responded by automatically commanding nose down.

Investigation of the incident revealed that not only could the flight-control laws command a nose-down pitch, but pilots might not be able to counter the attitude - even if they pulled fully back on the sidestick.

The incident spurred an emergency change of procedures, instructing crews to turn off air data reference instruments if symptoms of a sensor jam emerged, or if the aircraft entered an "unmanageable pitch-down attitude" despite full-aft sidestick inputs.

Analysis of the A330 incident pointed to the possibility that conic plates on which the angle-of-attack sensors were mounted had contributed to icing and a subsequent blockage.

Jamming of two or three sensors at the same angle could cause the stall-protection system to activate, investigators stated.

Operators were instructed, in early 2013, to replace the conic plates with a flat-plate mounting for the sensors.

But a similar incident, in November 2014, involving a Lufthansa A321 climbing out of Bilbao underscored the difficulties in anticipating misbehaviour.

Two of the A321's angle-of-attack sensors froze at a position of 4.5° as the jet passed 19,500ft. It continued to climb but, as it reached 31,000ft, the crew observed airspeed discrepancies and switched off the autopilot, bringing the aircraft under manual control.

The A321 abruptly pitched 3.5° nose-down because, at the speed of Mach 0.675, the jammed sensors were incorrectly showing an angle of attack greater than the 4.2° threshold for the stall-protection system.

With two of the three angle-of-attack sensors jammed at a consistent, albeit wrong, position the A321's air data reference system eliminated the apparently spurious readings from the third sensor. As a result the elevator aileron computer - which controls pitch through the elevators and horizontal stabiliser - took into account only the two incorrect sensors.

"Before these events occurred, the models had accumulated a significant number of flight hours without any such issue" EASA

The aircraft entered a 4,000ft/min descent and the captain was only able to restore and maintain level flight by pulling fully back on the sidestick. Manual nose-up trim was unavailable. Control was eventually regained through measures that led the aircraft to revert to alternate flight law, disengaging the stall-protection system.

Investigators discovered, in the wake of the incident, that the A321 was not fitted with the conic sensor plates suspected in the A330 event, but conventional flat plates. Water ingestion was considered a contributor.

Airbus and the European Union Aviation Safety Agency (EASA) warned A330 and A320-family crews that, if the Mach number continued to increase during a nose-down command, the angle-of-attack threshold for activating stall-protection would continue to decline - resulting in further nose-down orders from the flight-control system.

Pilots were issued with new emergency procedures that instructed them to turn off two of the three air data reference units, forcing the reversion to alternate flight law, if they observed symptoms of jammed angle-of-attack sensors.

There are crucial differences between the events that occurred on the Airbus jets and those preceding the 737 Max accidents, argues EASA.

"While the Airbus events were caused by multiple failures of the angle-of-attack system, the 737 Max issue seems to be caused by just one faulty sensor, thus presenting a higher probability risk," it says.

"The crew of the Airbus aircraft were able to recover control of the aircraft by switching to an alternate flight-control mode and the aircraft landed in a normal way."

EASA points out that, although the 737 has evolved over five decades, the 737 Max is "still a young aircraft model" with relatively little time since service entry in 2017.

"Before these [Airbus] events occurred, the Airbus aircraft models had accumulated a significant number of flight hours without any such issue, allowing certification authorities to perform a comprehensive and robust continued airworthiness review," it adds.

Simultaneous jamming of two angle-of-attack sensors, and the rejection of a valid third, had previously led to the fatal crash of an A320 during a check flight at Perpignan in November 2008.

Water ingested by the sensors, left unprotected during routine washing, froze as the aircraft cruised at 32,000ft. The sensors jammed at low angle-of-attack settings - respectively 4.2° and 3.8° - and maintained these readings as the crew conducted the descent.

As a result the sensors were rendered inoperative and failed to detect the A320's increasing angle-of-attack when, as part of the check flight, the crew deliberately reduced airspeed at low altitude to test the stall-protection system. The aircraft slowed and the horizontal stabiliser trimmed nose-up but the protection system did not activate.

"The crew waited for the triggering of these protections while allowing the speed to fall to that of a stall," the inquiry by French investigation authority BEA found.

When the aircraft stalled, the crew increased thrust, and the stabiliser's nose-up position caused the A320 to pitch up. The crew failed to recover from the stall, which occurred at about 3,000ft; the jet lost height and crashed into the Mediterranean Sea.

EASA describes the high-incidence protection system on the A320 and A330 families as "robust", noting the inclusion of three angle-of-attack sensors compared with two on the 737 Max, normally enabling voting logic to eliminate a single erroneous reading. It adds that the Airbus has "enhanced" monitoring and surveillance of the sensors.

"Safety risk assessments are performed using a methodical approach that accounts for the severity of the potential consequence, the available mitigations - such as crew procedures - and the probability of the root cause to [occur or recur]."

All these considerations, it says, resulted in the differences in regulatory reaction and mandatory actions in the Airbus and Boeing cases.

Seven weeks before the Perpignan crash an upset involving an A330 in cruise exposed the virtual impossibility of certification testing every possible scenario involving flight-control response to corrupted air data.

A Qantas aircraft, operating at 37,000ft, experienced a sudden failure mode in one of the three air data inertial reference units, which started transmitting invalid and frequent spikes in angle-of-attack information.

While the data was invalid the system did not flag it as such. The aircraft's flight-control primary computer abruptly pitched the aircraft 8.4° nose-down, throwing almost all the unrestrained occupants to the ceiling. Over a third of the 315 people on board sustained injuries.

The precise mechanism for the data spikes could not be determined, and the Australian Transport Safety Bureau attributed the event to a "single, rare type of trigger" combined with a "marginal susceptibility" within the air data unit's central processor. Just three occurrences of similar data-spiking had occurred in 128 million hours of operation with the Northrop Grumman units, two of which involved the one fitted in the Qantas aircraft.

Analysis determined that the occurrence was the only known instance in which the design limitation had led to a pitch-down command in over 28 million flight hours on A330s and A340s - a rate that complied with the criteria for events classified as "hazardous" but not "catastrophic".

Investigators pointed out that the flight computer's algorithms were "generally very effective" and could handle "almost all possible situations" involving incorrect angle-of-attack data, adding that the design limitation was "very unlikely" to have led to a more adverse outcome.

Development of the A330 flight-control system involved "many elements to minimise the risk of a design error", including peer review, a system safety assessment, testing and simulation, none of which identified the limitation in the algorithm.

"Due to the wide range of potential inputs into a complex system… simulation and testing programs cannot exhaustively examine all the possible patterns of inputs," says the inquiry, stating that the testing activities for the flight-control computer "would not realistically" have included the multiple data-spike scenario.

Airbus nevertheless redesigned the angle-of-attack algorithm to prevent a recurrence of the Qantas incident, and improved the flight-control computer to enhance its ability to detect multiple angle-of-attack sensor blockages.

The A330 and A321 blockage incidents led EASA to order removal of specific angle-of-attack sensors and their replacement with equipment that was less susceptible to adverse environmental conditions.

Airbus also developed upgrades to the elevator and aileron computers, introducing improved sensor monitoring for the A320 family and later incorporating "flight-control aspects" for the A320neo family, says EASA.

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malpensante
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda malpensante » sab 04 mag 2019, 14:08:17

Molto interessante.
And Malpensa is going to be our Hub

I-GABE
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda I-GABE » sab 04 mag 2019, 14:50:37

malpensante ha scritto:Non ricordo di aver mai letto niente di più ipocrita in vita mia. Persino Cesare Battisti, che peraltro ha sulla coscienza solo qualche morto e non centinaia, ultimamente mi sembra più serio.


Dovrebbe andare a ripetizione dai colleghi delle case farmaceutiche US - a partire da JnJ - sul come gestire situazioni di questo tipo.
Per quanto in ultima istanza sarà qualche altra testa a cadere come capro espiatorio, la difesa a oltranza in questo modo è assolutamente suicida.


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kco
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda kco » lun 13 mag 2019, 08:00:59

Situazione legale:

https://www.bloomberg.com/amp/news/arti ... ssion=true

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malpensante
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda malpensante » lun 13 mag 2019, 10:19:37

E Muilenburg è ancora alla cloche.
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Tulkas
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda Tulkas » lun 13 mag 2019, 22:46:08

Return of Boeing’s 737 MAX Delayed, Posing Further Headaches for Airlines
Planes may not be restored to airline schedules before mid-August or even later, missing most of the summer travel season

https://www.wsj.com/articles/timeline-f ... 1557758701

kco
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda kco » gio 16 mag 2019, 21:04:16

https://www.seattletimes.com/business/b ... ssion=true

Alcuni commenti mi lasciano un po' così... Non sono sicuro che tutti i piloti usa ce l'avrebbero fatta senza problemi...

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easyMXP
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda easyMXP » gio 16 mag 2019, 21:20:18

Gli americani ce l'hanno sempre più duro di tutti.
Però gli altri aerei in mano agli stessi scarsi (secondo loro) piloti del resto del mondo non danno particolari problemi, il Max se non lo pilota un top gun cade ogni 6 mesi a causa di un design approssimativo e una safety analysis fatta male, e probabilmente intenzionalmente male.

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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda malpensante » gio 16 mag 2019, 21:56:30

La soluzione è allora consentire il MAX alle linee aeree yankee e vietarlo alle altre.
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I-Alex
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda I-Alex » ven 17 mag 2019, 07:26:45

La risposta dei piloti Usa

In a statement Thursday, APA President Captain Daniel Carey cited the November meeting and said, “It’s six months later and who knows how long it will take to implement the new fix, and if it’s even sufficient.”
“Dennis Muilenberg and his engineers need to take full responsibility for the 346 deaths,” Carey added. “Boeing needs to stop dodging responsibility and stop blaming dead pilots for its mistakes.”


https://www.seattletimes.com/business/b ... a-approval
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malpensante
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Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda malpensante » ven 17 mag 2019, 11:48:29

Non gliel’hanno mandato a dire.
Io non vedo una soluzione veloce.
And Malpensa is going to be our Hub

kco
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda kco » sab 18 mag 2019, 10:16:20

Da copia di flight international in mio possesso

Development of the updated flight-control software for the 737 Max is finished and Boeing is now working with the US Federal Aviation Administration (FAA) to schedule certification test flights.

The airframer has also wrapped up simulator testing and engineering test flights for the Max. To date, Boeing has accumulated more than 360h across 207 flights on the updated Maneuvering Characteristics Augmentation System (MCAS) software.

"We are now providing additional information to address [FAA] requests that include additional detail on how pilots interact with the airplane controls and displays in different flight scenarios," says Boeing.

The 737 Max was grounded globally following the 10 March crash of an Ethiopian Airlines example, in an accident linked to erroneous activation of MCAS.

The announcement of progress on the software update came a day after the FAA's acting administrator, Dan Elwell, was grilled by US lawmakers examining the certification of the 737 Max and regulatory oversight of Boeing.

Elwell sat before a House Transportation Committee panel for hours, during which he expressed confidence in the FAA's certification work.

But he concedes pilots should have been better informed about the system: "When I first heard of this, I thought that the MCAS should have been more adequately explained… in the manual," Elwell says.

Elwell agrees that the MCAS was "safety critical", but defends the fact that it could be activated by inputs from just a single angle-of-attack sensor, noting that pilots should easily be able to counter the system.

The FAA has reviewed an initial version of Boeing's software fix for the Max, but has not received the final iteration.

"We are expecting the application of the formal MCAS software update soon," Elwell says. "The 737 Max will return to service only when the FAA's analysis indicates that it is safe to do so."

The hearing also served as a forum for lawmakers to opine on both sides of the debate swirling around the 737 Max: whether pilot error or aircraft design was the primary factor in the two fatal crashes of the type.

Overspeed was the "fundamental error", says Republican congressman Sam Graves, referring to the crew of the ill-fated Ethiopian flight, claiming that such a crash could not happen in the USA due to higher standards of pilot training.

However, Robert Sumwalt, chair of US accident investigation body the National Transportation Safety Board, says aircraft must be designed to be safe in the hands of pilots from different regions of the world, with differing levels of training.

"If an aircraft manufacturer is going to sell aircraft all across the globe, it's important that pilots… in all parts of the globe need to know how to operate them," he says.



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I-GABE
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda I-GABE » sab 18 mag 2019, 10:40:25

Non avevo letto la dichiarazione di Graves (nomina sunt omina?), ma è surreale.
Come già detto da altri, ci volino loro sui max!


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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda malpensante » sab 18 mag 2019, 11:37:54

Come dice Trump, Boeing dovrebbe cambiare nome al MAX. 737 Graves andrebbe benissimo.
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mattaus313
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Re: Precipitato un B737 Max 8 di Ethiopian

Messaggio da leggereda mattaus313 » sab 18 mag 2019, 15:01:18

Intanto...

Three prominent sales executives are retiring from Boeing Co., leaving key vacancies on the planemaker’s global commercial-marketing team ahead of next month’s Paris Air Show, the aerospace industry’s largest trade expo.

With the turnover, Boeing loses executives with deep customer relationships in some of its most critical markets as the company tries to rebuild confidence in the 737 Max after two fatal crashes. Boeing, which like Airbus is off to a slow start on jetliner sales this year, must also navigate U.S.-China trade tensions.


https://www.bloomberg.com/news/articles ... ium=social
"Because you needed a lot of capital in an airline, you needed to be where the financial markets were, and obviously that's New York"


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