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再曝“黑料”！波音向全世界隐瞒了737MAX这一“致命问题”……
2019-04-30 04:08
【环球时报驻美国特派特约记者 张梦旭 温燕】据法新社4月29日报道，在2018年印尼狮航空难后，美国联邦航空管理局(FAA)内部就有官员提出停飞部分波音737 MAX客机，但是这一意见并未到达该机构最高层。去年10月印尼狮航空难前，联邦航空管理局的检查员发现，波音曾主动关闭“机动特性增强系统”(MCAS)故障显示灯，但却没有通报FAA和相关航空公司。波音将该警报系统作为可选配置，只有在航空公司购买一套额外安全功能包的情况下才可以使用。
美国《华尔街日报》29日报道称，这一显示灯是用于告知飞行员“迎角传感器”是否正在传输错误的机头仰俯数据。行业和政府官员表示，在波音737 MAX于2017年投入使用一年多后，美国西南航空的管理层和机组人员仍不知道飞机未配置该警报系统。《华尔街日报》引述内部文件称，在狮航客机坠毁后不到一个月，一名FAA官员写道：“该机型上的迎角问题可能掩盖了一个更大的系统隐患，这个隐患可能导致狮航式悲剧再次发生。”大约两周后，另外一份内部电子邮件写道：“让MAX飞机在迎角不一致警报系统失效的情况下飞行是极不负责任的。”
这些此前未被披露的邮件表明，早在埃航坠机事件发生前几个月，一些工作在一线的FAA检查人员就已经发出过警告。但这些顾虑几天后就被参与讨论的一些人打消了。这些人的结论是，该警报提供的是飞行员辅助性信息而非主要安全信息，因此不需要额外培训。波音和FAA此后继续公开声称MAX机型是安全的。
美国哥伦比亚广播公司(CBS)29日报道称，FAA近日接到至少4个波音雇员的举报电话。波音两次致命的飞机事故后，FAA为波音雇员和公众设定特殊热线以方便知情人举报相关问题。如今，FAA正将这些举报作为对波音737 MAX及其证书调查线索的一部分展开进一步调查。本月早些时候，国会参议院商务委员会根据举报者提供的相关线索对FAA验证程序启动调查。
据美国“商业内幕”网站29日报道，美国和欧洲多家航空公司因波音相关机型缺陷损失数亿美元。波音公司首席执行官丹尼斯·米伦伯格29日参加公司年度股东大会，这是自埃航事故后他首次与媒体见面。返回搜狐，查看更多
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Then expose the "black material"! Boeing has concealed the world from the "fatal problem" of 737MAX...
2019-04-30 04:08
[Global Times' special correspondent in the United States, Zhang Mengxu, Wen Yan] According to Agence France-Presse reported on April 29, after the Indonesian Lions Airlines in 2018, officials within the Federal Aviation Administration (FAA) proposed to stop flying some Boeing 737 MAX Passenger aircraft, but this opinion did not reach the highest level of the agency. Before the Indonesian Lions Airways disaster in October last year, the Federal Aviation Administration inspectors found that Boeing had actively turned off the "Machine Feature Enhancement System" (MCAS) fault display light, but did not inform the FAA and related airlines. Boeing has this alarm system as an option and can only be used if the airline has purchased an additional set of safety features.
The US "Wall Street Journal" reported on the 29th that this indicator light is used to inform the pilot whether the "angle of attack sensor" is transmitting the wrong head tilt data. Industry and government officials said that after the Boeing 737 MAX was put into use in 2017, the management and crew of Southwest Airlines still did not know that the aircraft was not equipped with the alarm system. The Wall Street Journal quoted internal documents as saying that less than a month after the crash of the Lion Airliner, an FAA official wrote: "The angle of attack problem on this model may mask a larger systemic hazard, which may lead to The Lion Air tragedy recurred." About two weeks later, another internal email wrote: "It is extremely irresponsible for the MAX aircraft to fly in the event of an inconsistent angle of attack warning system."
These previously undisclosed e-mails indicate that some FAA inspectors who had been on the front line had issued warnings a few months before the E-Air crash. But these concerns were dispelled by some of the people who participated in the discussion a few days later. These people conclude that the alert provides pilot-assisted information rather than primary safety information, so no additional training is required. Boeing and the FAA continue to publicly claim that the MAX model is safe.
CBS reported on the 29th that the FAA recently received a report call from at least four Boeing employees. After Boeing’s two fatal aircraft accidents, the FAA set up a special hotline for Boeing employees and the public to help informers report relevant issues. Today, the FAA is investigating these reports as part of a survey of Boeing 737 MAX and its certification. Earlier this month, the Senate Commerce Committee launched an investigation into the FAA verification process based on relevant clues provided by the reporter.
According to the US "Business Insider" website on the 29th, many airlines in the United States and Europe lost hundreds of millions of dollars due to Boeing-related model defects. Boeing CEO Dennis Millenberg attended the company's annual shareholder meeting on the 29th, which was the first time he met with the media since the Ethiopian accident. Go back to Sohu and see more
https://www.channelnewsasia.com/news/world/boeing-737-max-to-get-new-warning-light-11368218
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Then expose the "black material"! Boeing has concealed the world from the "fatal problem" of 737MAX...
2019-04-30 04:08
[Global Times' special correspondent in the United States, Zhang Mengxu, Wen Yan] According to Agence France-Presse reported on April 29, after the Indonesian Lions Airlines in 2018, officials within the Federal Aviation Administration (FAA) proposed to stop flying some Boeing 737 MAX Passenger aircraft, but this opinion did not reach the highest level of the agency. Before the Indonesian Lions Airways disaster in October last year, the Federal Aviation Administration inspectors found that Boeing had actively turned off the "Machine Feature Enhancement System" (MCAS) fault display light, but did not inform the FAA and related airlines. Boeing has this alarm system as an option and can only be used if the airline has purchased an additional set of safety features.
The US "Wall Street Journal" reported on the 29th that this indicator light is used to inform the pilot whether the "angle of attack sensor" is transmitting the wrong head tilt data. Industry and government officials said that after the Boeing 737 MAX was put into use in 2017, the management and crew of Southwest Airlines still did not know that the aircraft was not equipped with the alarm system. The Wall Street Journal quoted internal documents as saying that less than a month after the crash of the Lion Airliner, an FAA official wrote: "The angle of attack problem on this model may mask a larger systemic hazard, which may lead to The Lion Air tragedy recurred." About two weeks later, another internal email wrote: "It is extremely irresponsible for the MAX aircraft to fly in the event of an inconsistent angle of attack warning system."
These previously undisclosed e-mails indicate that some FAA inspectors who had been on the front line had issued warnings a few months before the E-Air crash. But these concerns were dispelled by some of the people who participated in the discussion a few days later. These people conclude that the alert provides pilot-assisted information rather than primary safety information, so no additional training is required. Boeing and the FAA continue to publicly claim that the MAX model is safe.
CBS reported on the 29th that the FAA recently received a report call from at least four Boeing employees. After Boeing’s two fatal aircraft accidents, the FAA set up a special hotline for Boeing employees and the public to help informers report relevant issues. Today, the FAA is investigating these reports as part of a survey of Boeing 737 MAX and its certification. Earlier this month, the Senate Commerce Committee launched an investigation into the FAA verification process based on relevant clues provided by the reporter.
According to the US "Business Insider" website on the 29th, many airlines in the United States and Europe lost hundreds of millions of dollars due to Boeing-related model defects. Boeing CEO Dennis Millenberg attended the company's annual shareholder meeting on the 29th, which was the first time he met with the media since the Ethiopian accident. Go back to Sohu and see more
World Wide Web
610,000 articles
26.1 billion total reading
View TA's article >
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share to
Then expose the "black material"! Boeing has concealed the world from the "fatal problem" of 737MAX...
2019-04-30 04:08
[Global Times' special correspondent in the United States, Zhang Mengxu, Wen Yan] According to Agence France-Presse reported on April 29, after the Indonesian Lions Airlines in 2018, officials within the Federal Aviation Administration (FAA) proposed to stop flying some Boeing 737 MAX Passenger aircraft, but this opinion did not reach the highest level of the agency. Before the Indonesian Lions Airways disaster in October last year, the Federal Aviation Administration inspectors found that Boeing had actively turned off the "Machine Feature Enhancement System" (MCAS) fault display light, but did not inform the FAA and related airlines. Boeing has this alarm system as an option and can only be used if the airline has purchased an additional set of safety features.
The US "Wall Street Journal" reported on the 29th that this indicator light is used to inform the pilot whether the "angle of attack sensor" is transmitting the wrong head tilt data. Industry and government officials said that after the Boeing 737 MAX was put into use in 2017, the management and crew of Southwest Airlines still did not know that the aircraft was not equipped with the alarm system. The Wall Street Journal quoted internal documents as saying that less than a month after the crash of the Lion Airliner, an FAA official wrote: "The angle of attack problem on this model may mask a larger systemic hazard, which may lead to The Lion Air tragedy recurred." About two weeks later, another internal email wrote: "It is extremely irresponsible for the MAX aircraft to fly in the event of an inconsistent angle of attack warning system."
These previously undisclosed e-mails indicate that some FAA inspectors who had been on the front line had issued warnings a few months before the E-Air crash. But these concerns were dispelled by some of the people who participated in the discussion a few days later. These people conclude that the alert provides pilot-assisted information rather than primary safety information, so no additional training is required. Boeing and the FAA continue to publicly claim that the MAX model is safe.
CBS reported on the 29th that the FAA recently received a report call from at least four Boeing employees. After Boeing’s two fatal aircraft accidents, the FAA set up a special hotline for Boeing employees and the public to help informers report relevant issues. Today, the FAA is investigating these reports as part of a survey of Boeing 737 MAX and its certification. Earlier this month, the Senate Commerce Committee launched an investigation into the FAA verification process based on relevant clues provided by the reporter.
According to the US "Business Insider" website on the 29th, many airlines in the United States and Europe lost hundreds of millions of dollars due to Boeing-related model defects. Boeing CEO Dennis Millenberg attended the company's annual shareholder meeting on the 29th, which was the first time he met with the media since the Ethiopian accident. Go back to Sohu and see more
https://graphics.reuters.com/ETHIOPIA-AIRLINE-CONTROLS/0100916V1NZ/index.html
EXPLAINER
Change to 737 MAX controls may have imperiled planes, experts say
By Alwyn Scott, Wen Foo and Eric M. Johnson
PUBLISHED March 22, 2019
Much like tapping the brake pedal in a car to disengage cruise control, a sharp tug on the controls of older models of Boeing Co’s 737 used to shut off an automatic trim system that keeps the plane flying level, giving the pilot control.
But Boeing disabled the “yoke jerk” function when it brought out the 737 MAX, the latest version of its top-selling jet — and many pilots were unaware of the change, aviation experts told Reuters.
The difference may help explain why pilots struggled to keep their aircraft climbing after takeoff on two fatal 737 MAX flights less than five months apart that killed 346 people.
Pilots of a Lion Air flight that crashed in October scoured a handbook for answers as the plane repeatedly lurched downward in the first minutes of flight, Reuters reported.
An Ethiopian Airlines flight that went down on March 10 showed “clear similarities” to the Lion Air accident, aviation authorities said after seeing black-box data.
Engine changes
The 737 MAX has larger and more fuel-efficient engines that are placed higher and further forward on the wing, changing the jet’s balance and how the jet handles in certain situations.
Source: Boeing
A pair of switches on the center console between the pilots will turn off the automatic trim and a mechanism, new on the 737 MAX, known as the Maneuver Characteristics Augmentation System, or MCAS, that is suspected of playing a role in both disasters.
But pilots would have needed to know that MCAS existed, that it had unusual power to force the plane down and that “a hard pull on the yoke” would no longer turn off the automatic trim that uses MCAS, John Hansman, an aeronautics professor at MIT, said in an interview.
“That wasn’t clear to the pilots flying the airplane,” Hansman said. “The training material was not clear on that.”
INSIDE A 737 MAX 8 COCKPIT
737 MAX COCKPITThe 737 MAX controls are similar to the previous model and minimize pilot retraining. This picture shows the cockpit of a Jet Airways 737 MAX 8 plane from June 2018.
YOKEIn previous 737 models, a hard pull on the yoke or control wheel would shut off the automatic trim system that keeps the plane flying properly. That shut off was disabled in 737 MAX models.
STABILIZER TRIM CONTROLRocker switches on the yoke allow the pilot to adjust the airplane’s trim but can be overridden by the automatic trim system and the Maneuver Characteristics Augmentation System (MCAS).
TRIM WHEELSThese allow pilots to adjust trim manually or using automatic trim system.
STAB TRIM SWITCHESTwo switches allow pilots to turn off the automatic trim system, which also turns off MCAS.
Boeing declined to comment. In the aftermath of the Lion Air crash, Boeing pointed to long-established procedures that pilots could have used to handle a malfunction of the anti-stall system, regardless of whether the pilots knew MCAS existed.
That checklist tells pilots to switch off the two stabilizer trim cutout switches on the central console, and then to adjust the aircraft’s stabilizers manually using trim wheels.
An American Airlines flight manual mentions MCAS only in a table of acronyms, according to an October 2018 edition of the 1,400-page book seen by Reuters. Pilots have raised questions about why more detail on MCAS was not included.
The American Airlines manual’s two-page description of trim controls describes a “trim circuit,” but not how MCAS could be triggered by a faulty sensor reading, which is also suspected in the two crashes.
The MCAS system was designed to counteract the effect on the plane’s handling caused by new larger 737 MAX engines, which had to be placed farther forward and higher on the wings because the 50-year-old 737 design sits relatively low to the ground. That move gave the MAX a tendency to nose up into a stall, a dangerous position in which a plane loses lift as too little air flows across its wings.
MCAS, essentially a few lines of computer code in the flight control system, relies on data from two small, blade-shaped sensors near the nose of the aircraft that measure the angle of air flow. Faults in the sensors are not uncommon, and MCAS relies on only one sensor at a time during flight. In the Lion Air crash, investigators found a faulty reading led the plane’s computer to believe it was stalled and to push the nose down.
Boeing later issued a bulletin reminding pilots how to respond to such a faulty reading. An optional warning light could have alerted pilots to the faulty sensor.
HOW THE ANTI-STALL SENSOR WORKS
Boeing installed an automated anti-stall system called the Maneuvering Characteristics Augmentation System (MCAS) to address the jet’s changed balance after the planemaker installed larger engines and moved them forward.
MCAS is designed to prevent a stall, the loss of lift that occurs when too little air is flowing across the top of an aircraft’s wings.
SENSORSAnti-stall sensors are located on either side of the plane’s nose. One of the sensors is highlighted above on a Lion Air 737 MAX 8 jet.Photo by Reuters/Willy Kurniawan
When the nose is level...
The angle of attack (AOA) sensors, which measure the angle between the airflow and the wing, align with oncoming airflow. The sensors tell MCAS when the wings are losing airflow because the plane’s nose is pointed too high.
When the nose is elevated...
The angle of attack rises and when it becomes too high, the anti-stall system activates. MCAS then tilts the smaller wing (horizontal stabilizer) in the tail of the aircraft to force the plane’s nose down and restore airflow.
Source: Boeing
Investigators unraveling the Lion Air crash are looking at maintenance records and whether the pilots had enough training to handle the emergency, among other factors.
The 737 MAX can fly without MCAS, so the feature was not considered “flight-critical” even though it has extraordinary power to steer the plane, said an industry expert with knowledge of the system who spoke on condition of anonymity. MCAS controls the large horizontal wing on the plane’s tail known as the stabilizer, while the pilot controls smaller flaps or “elevators” on the stabilizer.
Over several minutes, the stabilizer can shift position enough that the elevator controls can no longer counteract the downward direction of the plane, the source said.
Ground altitude
Data released by flight tracking website Flightradar 24 indicates that both the Lion Air and Ethiopian Airlines planes that crashed suddenly lost altitude in the first few minutes following takeoff.
0200400600 seconds 0 2,000 4,0006,000 feetLion Air Flight 610Ethiopian Airlines Flight 302
Note: Data begins with the first recorded data point and may not always start from zero. Data ends on the last recorded datapoint.
Source: Flightradar24
“They gave more control power to the automation than to the pilot,” the source said of the MCAS design.
The Lion Air pilots flew for about five minutes by using the elevator to counteract the stabilizer every 15 or 20 seconds, said Hansman, based on readings from the flight data recorder. After that, the pilot tried pulling back hard on the controls.
“That’s what suggests that the crew didn’t understand the system. They thought they were shutting MCAS off and didn’t,” Hansman said. “Whereas any time during the entire sequence, they could have reached to the middle console and just shut it off.”
Top image: A Boeing 737 MAX takes part in flying display during the 52nd Paris Air Show at Le Bourget Airport near Paris, France in June 2017. Photo by Reuters/Pascal Rossignol
Reporting by Alwyn Scott in New York, Eric M. Johnson in Seattle and Hwei Wen Foo in Singapore
Additional work by Christine Chan and Travis Hartman
Editing by Nick Zieminski and Bill Rigby
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再曝“黑料”！波音向全世界隐瞒了737MAX这一“致命问题”……
2019-04-30 04:08
【环球时报驻美国特派特约记者 张梦旭 温燕】据法新社4月29日报道，在2018年印尼狮航空难后，美国联邦航空管理局(FAA)内部就有官员提出停飞部分波音737 MAX客机，但是这一意见并未到达该机构最高层。去年10月印尼狮航空难前，联邦航空管理局的检查员发现，波音曾主动关闭“机动特性增强系统”(MCAS)故障显示灯，但却没有通报FAA和相关航空公司。波音将该警报系统作为可选配置，只有在航空公司购买一套额外安全功能包的情况下才可以使用。
美国《华尔街日报》29日报道称，这一显示灯是用于告知飞行员“迎角传感器”是否正在传输错误的机头仰俯数据。行业和政府官员表示，在波音737 MAX于2017年投入使用一年多后，美国西南航空的管理层和机组人员仍不知道飞机未配置该警报系统。《华尔街日报》引述内部文件称，在狮航客机坠毁后不到一个月，一名FAA官员写道：“该机型上的迎角问题可能掩盖了一个更大的系统隐患，这个隐患可能导致狮航式悲剧再次发生。”大约两周后，另外一份内部电子邮件写道：“让MAX飞机在迎角不一致警报系统失效的情况下飞行是极不负责任的。”
这些此前未被披露的邮件表明，早在埃航坠机事件发生前几个月，一些工作在一线的FAA检查人员就已经发出过警告。但这些顾虑几天后就被参与讨论的一些人打消了。这些人的结论是，该警报提供的是飞行员辅助性信息而非主要安全信息，因此不需要额外培训。波音和FAA此后继续公开声称MAX机型是安全的。
美国哥伦比亚广播公司(CBS)29日报道称，FAA近日接到至少4个波音雇员的举报电话。波音两次致命的飞机事故后，FAA为波音雇员和公众设定特殊热线以方便知情人举报相关问题。如今，FAA正将这些举报作为对波音737 MAX及其证书调查线索的一部分展开进一步调查。本月早些时候，国会参议院商务委员会根据举报者提供的相关线索对FAA验证程序启动调查。
据美国“商业内幕”网站29日报道，美国和欧洲多家航空公司因波音相关机型缺陷损失数亿美元。波音公司首席执行官丹尼斯·米伦伯格29日参加公司年度股东大会，这是自埃航事故后他首次与媒体见面。返回搜狐，查看更多
World Wide Web
610,000 articles
26.1 billion total reading
View TA's article >
32
share to
Then expose the "black material"! Boeing has concealed the world from the "fatal problem" of 737MAX...
2019-04-30 04:08
[Global Times' special correspondent in the United States, Zhang Mengxu, Wen Yan] According to Agence France-Presse reported on April 29, after the Indonesian Lions Airlines in 2018, officials within the Federal Aviation Administration (FAA) proposed to stop flying some Boeing 737 MAX Passenger aircraft, but this opinion did not reach the highest level of the agency. Before the Indonesian Lions Airways disaster in October last year, the Federal Aviation Administration inspectors found that Boeing had actively turned off the "Machine Feature Enhancement System" (MCAS) fault display light, but did not inform the FAA and related airlines. Boeing has this alarm system as an option and can only be used if the airline has purchased an additional set of safety features.
The US "Wall Street Journal" reported on the 29th that this indicator light is used to inform the pilot whether the "angle of attack sensor" is transmitting the wrong head tilt data. Industry and government officials said that after the Boeing 737 MAX was put into use in 2017, the management and crew of Southwest Airlines still did not know that the aircraft was not equipped with the alarm system. The Wall Street Journal quoted internal documents as saying that less than a month after the crash of the Lion Airliner, an FAA official wrote: "The angle of attack problem on this model may mask a larger systemic hazard, which may lead to The Lion Air tragedy recurred." About two weeks later, another internal email wrote: "It is extremely irresponsible for the MAX aircraft to fly in the event of an inconsistent angle of attack warning system."
These previously undisclosed e-mails indicate that some FAA inspectors who had been on the front line had issued warnings a few months before the E-Air crash. But these concerns were dispelled by some of the people who participated in the discussion a few days later. These people conclude that the alert provides pilot-assisted information rather than primary safety information, so no additional training is required. Boeing and the FAA continue to publicly claim that the MAX model is safe.
CBS reported on the 29th that the FAA recently received a report call from at least four Boeing employees. After Boeing’s two fatal aircraft accidents, the FAA set up a special hotline for Boeing employees and the public to help informers report relevant issues. Today, the FAA is investigating these reports as part of a survey of Boeing 737 MAX and its certification. Earlier this month, the Senate Commerce Committee launched an investigation into the FAA verification process based on relevant clues provided by the reporter.
According to the US "Business Insider" website on the 29th, many airlines in the United States and Europe lost hundreds of millions of dollars due to Boeing-related model defects. Boeing CEO Dennis Millenberg attended the company's annual shareholder meeting on the 29th, which was the first time he met with the media since the Ethiopian accident. Go back to Sohu and see more
https://www.channelnewsasia.com/news/world/boeing-737-max-to-get-new-warning-light-11368218
World Wide Web
610,000 articles
26.1 billion total reading
View TA's article >
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Then expose the "black material"! Boeing has concealed the world from the "fatal problem" of 737MAX...
2019-04-30 04:08
[Global Times' special correspondent in the United States, Zhang Mengxu, Wen Yan] According to Agence France-Presse reported on April 29, after the Indonesian Lions Airlines in 2018, officials within the Federal Aviation Administration (FAA) proposed to stop flying some Boeing 737 MAX Passenger aircraft, but this opinion did not reach the highest level of the agency. Before the Indonesian Lions Airways disaster in October last year, the Federal Aviation Administration inspectors found that Boeing had actively turned off the "Machine Feature Enhancement System" (MCAS) fault display light, but did not inform the FAA and related airlines. Boeing has this alarm system as an option and can only be used if the airline has purchased an additional set of safety features.
The US "Wall Street Journal" reported on the 29th that this indicator light is used to inform the pilot whether the "angle of attack sensor" is transmitting the wrong head tilt data. Industry and government officials said that after the Boeing 737 MAX was put into use in 2017, the management and crew of Southwest Airlines still did not know that the aircraft was not equipped with the alarm system. The Wall Street Journal quoted internal documents as saying that less than a month after the crash of the Lion Airliner, an FAA official wrote: "The angle of attack problem on this model may mask a larger systemic hazard, which may lead to The Lion Air tragedy recurred." About two weeks later, another internal email wrote: "It is extremely irresponsible for the MAX aircraft to fly in the event of an inconsistent angle of attack warning system."
These previously undisclosed e-mails indicate that some FAA inspectors who had been on the front line had issued warnings a few months before the E-Air crash. But these concerns were dispelled by some of the people who participated in the discussion a few days later. These people conclude that the alert provides pilot-assisted information rather than primary safety information, so no additional training is required. Boeing and the FAA continue to publicly claim that the MAX model is safe.
CBS reported on the 29th that the FAA recently received a report call from at least four Boeing employees. After Boeing’s two fatal aircraft accidents, the FAA set up a special hotline for Boeing employees and the public to help informers report relevant issues. Today, the FAA is investigating these reports as part of a survey of Boeing 737 MAX and its certification. Earlier this month, the Senate Commerce Committee launched an investigation into the FAA verification process based on relevant clues provided by the reporter.
According to the US "Business Insider" website on the 29th, many airlines in the United States and Europe lost hundreds of millions of dollars due to Boeing-related model defects. Boeing CEO Dennis Millenberg attended the company's annual shareholder meeting on the 29th, which was the first time he met with the media since the Ethiopian accident. Go back to Sohu and see more
World Wide Web
610,000 articles
26.1 billion total reading
View TA's article >
32
share to
Then expose the "black material"! Boeing has concealed the world from the "fatal problem" of 737MAX...
2019-04-30 04:08
[Global Times' special correspondent in the United States, Zhang Mengxu, Wen Yan] According to Agence France-Presse reported on April 29, after the Indonesian Lions Airlines in 2018, officials within the Federal Aviation Administration (FAA) proposed to stop flying some Boeing 737 MAX Passenger aircraft, but this opinion did not reach the highest level of the agency. Before the Indonesian Lions Airways disaster in October last year, the Federal Aviation Administration inspectors found that Boeing had actively turned off the "Machine Feature Enhancement System" (MCAS) fault display light, but did not inform the FAA and related airlines. Boeing has this alarm system as an option and can only be used if the airline has purchased an additional set of safety features.
The US "Wall Street Journal" reported on the 29th that this indicator light is used to inform the pilot whether the "angle of attack sensor" is transmitting the wrong head tilt data. Industry and government officials said that after the Boeing 737 MAX was put into use in 2017, the management and crew of Southwest Airlines still did not know that the aircraft was not equipped with the alarm system. The Wall Street Journal quoted internal documents as saying that less than a month after the crash of the Lion Airliner, an FAA official wrote: "The angle of attack problem on this model may mask a larger systemic hazard, which may lead to The Lion Air tragedy recurred." About two weeks later, another internal email wrote: "It is extremely irresponsible for the MAX aircraft to fly in the event of an inconsistent angle of attack warning system."
These previously undisclosed e-mails indicate that some FAA inspectors who had been on the front line had issued warnings a few months before the E-Air crash. But these concerns were dispelled by some of the people who participated in the discussion a few days later. These people conclude that the alert provides pilot-assisted information rather than primary safety information, so no additional training is required. Boeing and the FAA continue to publicly claim that the MAX model is safe.
CBS reported on the 29th that the FAA recently received a report call from at least four Boeing employees. After Boeing’s two fatal aircraft accidents, the FAA set up a special hotline for Boeing employees and the public to help informers report relevant issues. Today, the FAA is investigating these reports as part of a survey of Boeing 737 MAX and its certification. Earlier this month, the Senate Commerce Committee launched an investigation into the FAA verification process based on relevant clues provided by the reporter.
According to the US "Business Insider" website on the 29th, many airlines in the United States and Europe lost hundreds of millions of dollars due to Boeing-related model defects. Boeing CEO Dennis Millenberg attended the company's annual shareholder meeting on the 29th, which was the first time he met with the media since the Ethiopian accident. Go back to Sohu and see more
https://graphics.reuters.com/ETHIOPIA-AIRLINE-CONTROLS/0100916V1NZ/index.html
EXPLAINER
Change to 737 MAX controls may have imperiled planes, experts say
By Alwyn Scott, Wen Foo and Eric M. Johnson
PUBLISHED March 22, 2019
Much like tapping the brake pedal in a car to disengage cruise control, a sharp tug on the controls of older models of Boeing Co’s 737 used to shut off an automatic trim system that keeps the plane flying level, giving the pilot control.
But Boeing disabled the “yoke jerk” function when it brought out the 737 MAX, the latest version of its top-selling jet — and many pilots were unaware of the change, aviation experts told Reuters.
The difference may help explain why pilots struggled to keep their aircraft climbing after takeoff on two fatal 737 MAX flights less than five months apart that killed 346 people.
Pilots of a Lion Air flight that crashed in October scoured a handbook for answers as the plane repeatedly lurched downward in the first minutes of flight, Reuters reported.
An Ethiopian Airlines flight that went down on March 10 showed “clear similarities” to the Lion Air accident, aviation authorities said after seeing black-box data.
Engine changes
The 737 MAX has larger and more fuel-efficient engines that are placed higher and further forward on the wing, changing the jet’s balance and how the jet handles in certain situations.
Source: Boeing
A pair of switches on the center console between the pilots will turn off the automatic trim and a mechanism, new on the 737 MAX, known as the Maneuver Characteristics Augmentation System, or MCAS, that is suspected of playing a role in both disasters.
But pilots would have needed to know that MCAS existed, that it had unusual power to force the plane down and that “a hard pull on the yoke” would no longer turn off the automatic trim that uses MCAS, John Hansman, an aeronautics professor at MIT, said in an interview.
“That wasn’t clear to the pilots flying the airplane,” Hansman said. “The training material was not clear on that.”
INSIDE A 737 MAX 8 COCKPIT
737 MAX COCKPITThe 737 MAX controls are similar to the previous model and minimize pilot retraining. This picture shows the cockpit of a Jet Airways 737 MAX 8 plane from June 2018.
YOKEIn previous 737 models, a hard pull on the yoke or control wheel would shut off the automatic trim system that keeps the plane flying properly. That shut off was disabled in 737 MAX models.
STABILIZER TRIM CONTROLRocker switches on the yoke allow the pilot to adjust the airplane’s trim but can be overridden by the automatic trim system and the Maneuver Characteristics Augmentation System (MCAS).
TRIM WHEELSThese allow pilots to adjust trim manually or using automatic trim system.
STAB TRIM SWITCHESTwo switches allow pilots to turn off the automatic trim system, which also turns off MCAS.
Boeing declined to comment. In the aftermath of the Lion Air crash, Boeing pointed to long-established procedures that pilots could have used to handle a malfunction of the anti-stall system, regardless of whether the pilots knew MCAS existed.
That checklist tells pilots to switch off the two stabilizer trim cutout switches on the central console, and then to adjust the aircraft’s stabilizers manually using trim wheels.
An American Airlines flight manual mentions MCAS only in a table of acronyms, according to an October 2018 edition of the 1,400-page book seen by Reuters. Pilots have raised questions about why more detail on MCAS was not included.
The American Airlines manual’s two-page description of trim controls describes a “trim circuit,” but not how MCAS could be triggered by a faulty sensor reading, which is also suspected in the two crashes.
The MCAS system was designed to counteract the effect on the plane’s handling caused by new larger 737 MAX engines, which had to be placed farther forward and higher on the wings because the 50-year-old 737 design sits relatively low to the ground. That move gave the MAX a tendency to nose up into a stall, a dangerous position in which a plane loses lift as too little air flows across its wings.
MCAS, essentially a few lines of computer code in the flight control system, relies on data from two small, blade-shaped sensors near the nose of the aircraft that measure the angle of air flow. Faults in the sensors are not uncommon, and MCAS relies on only one sensor at a time during flight. In the Lion Air crash, investigators found a faulty reading led the plane’s computer to believe it was stalled and to push the nose down.
Boeing later issued a bulletin reminding pilots how to respond to such a faulty reading. An optional warning light could have alerted pilots to the faulty sensor.
HOW THE ANTI-STALL SENSOR WORKS
Boeing installed an automated anti-stall system called the Maneuvering Characteristics Augmentation System (MCAS) to address the jet’s changed balance after the planemaker installed larger engines and moved them forward.
MCAS is designed to prevent a stall, the loss of lift that occurs when too little air is flowing across the top of an aircraft’s wings.
SENSORSAnti-stall sensors are located on either side of the plane’s nose. One of the sensors is highlighted above on a Lion Air 737 MAX 8 jet.Photo by Reuters/Willy Kurniawan
When the nose is level...
The angle of attack (AOA) sensors, which measure the angle between the airflow and the wing, align with oncoming airflow. The sensors tell MCAS when the wings are losing airflow because the plane’s nose is pointed too high.
When the nose is elevated...
The angle of attack rises and when it becomes too high, the anti-stall system activates. MCAS then tilts the smaller wing (horizontal stabilizer) in the tail of the aircraft to force the plane’s nose down and restore airflow.
Source: Boeing
Investigators unraveling the Lion Air crash are looking at maintenance records and whether the pilots had enough training to handle the emergency, among other factors.
The 737 MAX can fly without MCAS, so the feature was not considered “flight-critical” even though it has extraordinary power to steer the plane, said an industry expert with knowledge of the system who spoke on condition of anonymity. MCAS controls the large horizontal wing on the plane’s tail known as the stabilizer, while the pilot controls smaller flaps or “elevators” on the stabilizer.
Over several minutes, the stabilizer can shift position enough that the elevator controls can no longer counteract the downward direction of the plane, the source said.
Ground altitude
Data released by flight tracking website Flightradar 24 indicates that both the Lion Air and Ethiopian Airlines planes that crashed suddenly lost altitude in the first few minutes following takeoff.
0200400600 seconds 0 2,000 4,0006,000 feetLion Air Flight 610Ethiopian Airlines Flight 302
Note: Data begins with the first recorded data point and may not always start from zero. Data ends on the last recorded datapoint.
Source: Flightradar24
“They gave more control power to the automation than to the pilot,” the source said of the MCAS design.
The Lion Air pilots flew for about five minutes by using the elevator to counteract the stabilizer every 15 or 20 seconds, said Hansman, based on readings from the flight data recorder. After that, the pilot tried pulling back hard on the controls.
“That’s what suggests that the crew didn’t understand the system. They thought they were shutting MCAS off and didn’t,” Hansman said. “Whereas any time during the entire sequence, they could have reached to the middle console and just shut it off.”
Top image: A Boeing 737 MAX takes part in flying display during the 52nd Paris Air Show at Le Bourget Airport near Paris, France in June 2017. Photo by Reuters/Pascal Rossignol
Reporting by Alwyn Scott in New York, Eric M. Johnson in Seattle and Hwei Wen Foo in Singapore
Additional work by Christine Chan and Travis Hartman
Editing by Nick Zieminski and Bill Rigby
