Incidente Lion Air Indonesia 29.10.18

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danko156
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Re: Incidente Lion Air Indonesia 29.10.18

Messaggio da danko156 » 22 marzo 2019, 12:26

Aggiornamento da AvHerald:
On Mar 21st 2019 the KNKT reported another fully qualified Boeing 737-MAX 8 pilot was travelling home off duty on flight JT-43 from Denpasar to Jakarta, the flight immediately preceding the accident flight, which had encountered similiar problems as the accident flight, the crew of which however managed to land the aircraft at the destination. The pilot was interviewed by the KNKT. No further comments can be made. The KNKT also states, that media reports of what the CVR revealed do not match the actual CVR recordings and at the very best resemble just the personal opinions of people used as source for such media reports. The KNKT estimates the release of the final report for August or September 2019. The KNKT can not comment on possible similiarities between JT-610 and ET-302, however, have offered cooperation to the Ethiopian Authorities. Earlier media reports had suggested part of the CVR had been leaked to media, in addition media had reported a third pilot had occupied the observer's seat in the cockpit of flight JT-43 and was the one, who identified the automatic trim runaway issue at hand and initiated the trim cut out switches to be used.
http://avherald.com/h?article=4bf90724/0009&opt=0
DR
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Valerio Ricciardi
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Dopo il Final Report, azione legale della famiglia dell'unico italiano

Messaggio da Valerio Ricciardi » 2 novembre 2019, 9:07

Unico passeggero non indonesiano un nostro connazionale,
la famiglia comprensibilmente fa causa dopo aver avuto disponibile il Final Report di questo incidente.

https://www.corriere.it/cronache/19_nov ... 944c.shtml
"The curve is flattening: we can start lifting restrictions now" = "The parachute has slowed our rate of descent: we can take it off now!"
Chesley Burnett "Sully" Sullenberger

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Valerio Ricciardi
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Re: Incidente Lion Air Indonesia 29.10.18

Messaggio da Valerio Ricciardi » 11 dicembre 2019, 20:48

I tempi di ricertificazione si allungano... FAA non vuole correre alcun rischio

https://www.seattletimes.com/business/b ... red%20User
"The curve is flattening: we can start lifting restrictions now" = "The parachute has slowed our rate of descent: we can take it off now!"
Chesley Burnett "Sully" Sullenberger

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Re: Incidente Lion Air Indonesia 29.10.18

Messaggio da airplane » 6 gennaio 2020, 15:24

.

“Ogni disastro… Ha i suoi anelli della catena…”


[…] Two days before the final flight 610 (Lion Air 610), the airplane was in Bali, and technicians did more of the same. Additionally, in response to an error message indicating possible failures in angle-of-attack information, they replaced the angle-of-attack vane on the nose of the airplane on the captain’s side. Angle-of-attack vanes are exposed to the winds and are vulnerable to impact, ice and wear. The replacement vane put onto this airplane in Bali was older than the airplane itself. It was a used part that had been provided by a shop in Miramar, Fla., and shipped to Lion Air one year before. In the maintenance log in Bali, the company technicians documented replacing the angle-of-attack vane and testing it. They wrote, “Installation test and heater test result good.”

I had some doubts whether these tests were really run, and I mentioned these doubts to John Goglia, a no-nonsense Bostonian who spent 35 years as an airline mechanic and an additional nine years as a board member of the competent crash-investigation unit of the United States government, the National Transportation Safety Board. Goglia has followed the investigations surrounding the 737 Max closely. Speaking of the Lion Air mechanics, he said: “They’re full of shit. They suspected they found the problem in Bali. So they replaced one problem with another — a dubious unit from Cockroach Corner in Miami. Cockroach Corner is the source of tons of suspected unapproved parts. Many of those repair stations in Miami are junk peddlers.” And the Lion Air mechanics? He said: “They didn’t finish, whatever the log says. They didn’t do an adequate check of the systems.” If they had, in Goglia’s view, they would have seen that the unit was faulty.
According to the official narrative, which — discounting its omissions — seems to be mostly true, when a fresh crew arrived to take the next run, a night flight 600 miles west to Jakarta, a technician showed the new captain the maintenance log and explained that the angle-of-attack sensor on the left side had been replaced. The captain informed the co-pilot and said that he himself would do the flying. They would have a hitchhiker in the cockpit, sitting on the jump seat just behind them. He was an off-duty pilot and, according to one Indonesian pilot I spoke to, a 737 Max captain for a Lion Air subsidiary. For mysterious reasons, this man was not mentioned in subsequent Indonesian accounts. When I asked a senior investigator about the omission, he explained that it was because the investigators had been busy. Only recently and reluctantly have the Indonesians acknowledged the third pilot’s presence, though, as it happened, he played an important role.

None of the Bali crew have been named, and access to them has been blocked. The airplane took off at 10:20 p.m. with 189 people aboard, or 190 if the ghost in the cockpit is included. Immediately after liftoff, the captain’s airspeed indication failed, airspeed-disagreement and altitude-disagreement warnings appeared on his flight display and his stick shaker began to rattle the controls in warning of an imminent stall.

The Bali captain was enough of an airman to realize that he was dealing with an information failure only — not an actual stall. No direct mention has been made of this, but he must have immediately identified the replacement angle-of-attack vane on his side as the likely culprit. The co-pilot’s stick shaker had not activated. The second angle-of-attack sensor was functioning correctly. The captain held the airplane steady in the climb, confirmed that the right-side indications crosschecked with the standby instruments and transferred the flying to the co-pilot with instructions to follow a regular schedule of flap retractions and retrim the airplane as normal. The handoff was well done. The stick shaker continued to rattle, but that was merely an annoyance.

But then there was a change. What had been an information failure suddenly turned into a flight-control one. Soon after the flaps were retracted, the airplane developed a mind of its own and rolled in a fast burst of nose-down trim. Apparently, this caused such a lurch that back in the cabin some passengers started praying. It was just the MCAS kicking in, because the three conditions necessary to trigger it had combined: The flaps were up, the autopilot was off and the captain’s angle-of-attack sensor was showing a stall.

One of Boeing’s bewildering failures in the MCAS design is that despite the existence of two independent angle-of-attack sensors, the system did not require agreement between them to conclude that a stall had occurred. Inside the cockpit, none of the pilots knew any of this or had ever heard of the MCAS.
To them the event must have looked like a runaway trim, much as Boeing had expected. But there were two differences that may have confused them.
The first was the severity of the pitch-down trim, which ran twice as fast as a regular runaway — hence the praying in the cabin.
The second was that it lasted about only 10 seconds, then stopped for five seconds, then started again. The pattern repeated and would have kept repeating to the limits of nose-down trim, an extreme imbalance never approached in regular flight. This is another of Boeing’s bewildering failures — the implementation of an automated nose-down input meant to make for an authentic control feel but allowed to keep at it again and again while throwing the airplane wildly out of trim. No one I spoke to from Boeing, Airbus or the N.T.S.B. could explain the reasoning here.
MCAS trimming can be thwarted and even overpowered by counter-trimming with the sustained use of the thumb switches on the control yokes, but in the confusion of the encounter in Bali, the counter-trimming went only so far. After three MCAS impulses, the co-pilot said that his control column had grown so heavy that he could hardly hold the nose up. They were about six minutes into the flight and still on the runway heading. The captain formally declared a condition of urgency by making a “pan-pan” call to air-traffic control. He reported an instrument failure and asked to continue flying straight ahead. The controller approved the request and asked if the crew wanted to return to the airport. The captain answered, “Stand by.” Over the next two minutes, while the co-pilot fought to maintain control of the airplane, the captain went wandering through the checklists trying to figure out what to do.
Finally the ghost in the jump seat intervened. It is impossible to know if he was a better airman than the pilots in the front or simply had the advantage of an overview. Either way, he recommended the obvious — shutting off the electric trim by flipping the cutout switches. The captain flipped the switches, the trim stopped running away and the MCAS was disabled. It was that easy.

With the captain’s stick shaker continuing to rattle and the trim switches set to the off (cutout) position, the crew flew to Jakarta without further issue, adjusting trim as sometimes necessary by use of the manual trim wheels mounted on both sides of the central pedestal, and landed just before midnight. Investigators do not seem to have explored why the pilots required nearly five minutes to handle what normally might have been a 30-second adventure, or why they required a cockpit guest to provide the solution.
Such questions were overshadowed by the subsequent failures of the accident crew on Flight 610 […]



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