Внимательно почитайте начало второго абзаца:
DESCRIPTION: A pitch augmentation system function called “Maneuvering Characteristics Augmentation System“ (MCAS) is implemented on the 737-8, -9 (MAX) to enhance pitch characteristics with flaps UP and at elevated angles of attack. The MCAS function commands nose down stabilizer to enhance pitch characteristics during steep turns with elevated load factors and during flaps up flight at airspeeds approaching stall. MCAS is activated without pilot input and only operates in manual, flaps up flight. The system is designed to allow the flight crew to use column trim switch or stabilizer aisle stand cutout switches to override MCAS input. The function is commanded by the Flight Control computer using input data from sensors and other airplane systems.
The MCAS function becomes active when the airplane Angle of Attack exceeds a threshold based on airspeed and altitude. Stabilizer incremental commands are limited to 2.5 degrees and are provided at a rate of 0.27 degrees per second. The magnitude of the stabilizer input is lower at high Mach number and greater at low Mach numbers. The function is reset once angle of attack falls below the Angle of Attack threshold or if manual stabilizer commands are provided by the flight crew. If the original elevated AOA condition persists, the MCAS function commands another incremental stabilizer nose down command according to current aircraft Mach number at actuation.
The MCAS function is not incorporated on 737NG airplanes.
Тут вот WSJ про поиски CVR написал, теперь будут искать по-другому. Пока по своему жлобству не закрыли, сохранил себе. Выкладываю полностью:
Crashed Lion Air Plane’s Missing Black Box Goes Silent
Investigators are no longer detecting pings from Flight 610’s cockpit voice recorder and are preparing new equipment for search
By
Ben Otto
Nov. 16, 2018 6:54 a.m. ET
JAKARTA, Indonesia—Investigators searching for a black box of a crashed Lion Air jet believe its locator beacon is broken and are preparing new equipment to visually scour the muddy floor of the Java Sea.
Investigators are no longer detecting pings from the cockpit voice recorder, or CVR, which they believe is covered in mud at a depth of about 100 feet. A search area extends about 80 feet in all directions from a point where teams detected what they believed to be its pings in the days just after Flight 610 crashed after takeoff Oct. 29 from Jakarta.
Finding the device would provide important information to understanding the precise sequence of events that led to the crash a new Boeing 737 MAX 8. Investigators have pointed to problems related to a new stall-prevention system on the MAX jets, the latest variant of the Boeing single-aisle plane, that pilots in Indonesia and the U.S. have said they didn’t know about.
Authorities suspect a faulty sensor reading may have led the plane’s flight control system to incorrectly detect that the plane was at risk of stalling, kicking in an automatic system to push the nose down, a maneuver from which the crew was unable to recover. Investigators say Flight 610 crashed at high speed, obliterating the plane upon impact.
Edward Sirait, Lion Air’s chief executive, said Friday that three companies were being considered to bring in new equipment for the search. He declined to identify the companies and didn’t say when the new search would begin.
One person with knowledge of the preparation said an outside company would bring in a specialized search vessel with an advanced underwater vehicle. The search has been paused in the meantime.
“The only thing to do is go there with a remotely operated vehicle and check” point by point, said Muhammad Ilyas, head of marine survey technology at Indonesia’s Agency for the Assessment and Application of Technology. The agency helped locate and recover the other black box, the flight data recorder, by homing in on pings.
When the CVR’s pings went silent, search teams assumed it was functioning but undetectable under thick mud. But this week, Mr. Ilyas’s team and investigators buried beacons in about a foot and a half of mud—the approximate maximum thickness of the sediment layer in the search area—and found they could still detect pings.
“So now we assume the beacon has been damaged, ” Mr. Ilyas said. “But we’re confident the CVR can still be found.” He pointed to the crash of an Adam Air jet in Indonesia in 2007, when search teams using remotely operated vehicles needed seven months to retrieve the black boxes at a much greater depth.
The current search area is more than a hundred feet from where the main wreckage was found and is strewn with debris, making an underwater metal detector impractical, Mr. Ilyas said.
The maker of the beacon, Florida-based Dukane Seacom, said an exhaustive physical search was now the best option. “They will likely need to painstakingly comb the debris field, ” said Anish Patel, the company’s president. “I don’t know of any other quicker method.”
The beacon is designed to emit signals for 90 days, Mr. Patel said, but could have failed if, for example, the case was damaged enough to expose its batteries to water. “It would compromise operation but it is hard to say how quickly that would happen, ” he said.
The cockpit voice recorder would give investigators more insight into what the crew experienced when they encountered the suspected problems with inaccurate air speed information and the 737’s sudden nose-down maneuvers, as well as how the pilot and co-pilot may have tried to recover from the situation.
Some information, such as control inputs, can be gleaned from the roughly 1, 800 data points stored and recovered from the flight data recorder. But the voice recorder can be particularly helpful determining areas of confusion the crew may have suffered.
Boeing has come in for sharp criticism from 737 pilots for failing to notify them about the introduction of the new anti-stall system on the MAX. The plane maker and the U.S. Federal Aviation Administration, days after the Lion Air crash, alerted airlines about the feature and how it may react when fed erroneous angle of attack information. They also notified operators how to disable the system when it mistakenly pushes the plane’s nose down.
Boeing and the FAA are expected to agree on a mandatory fix to modify 737 MAX 8 planes, according to industry and government officials involved in or tracking the process. The fix would likely apply also to the slightly newer and larger 737 MAX 9 that features the same system. The FAA also said it was working with the plane maker to assess the need for further training and operating procedural changes.
—I Made Sentana and Robert Wall contributed to this article.
https://www.wsj.com/articles/c ...