On Mar 11th 2019 at 19:42Z the FAA announced: "Today, the FAA will issue a Continued Airworthiness Notification to the International Community (CANIC) for Boeing 737 MAX Operators." At 22:37Z the FAA released the CANIC for both Boeing 737-8 MAX and 737-9 MAX stating, they continue to monitor pending changes in the MCAS system, AoA Sensor Signal improvements and MCAS maximum command limits as well as training requirements associated with MCAS following their initial reaction to the crash of LionAir JT-610. The FAA states: "External reports are drawing similarities between this accident and the Lion Air Flight 610 accident on October 29, 2018. However, this investigation has just begun and to date we have not been provided data to draw any conclusions or take any actions."
魚翅航空無女2019-03-12 12:34:51
On Mar 12th 2019 Boeing issued following release with respect to MCAS, Lion Air Flight 610 and Ethiopian flight 302:
For the past several months and in the aftermath of Lion Air Flight 610, Boeing has been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer. This includes updates to the Maneuvering Characteristics Augmentation System (MCAS) flight control law, pilot displays, operation manuals and crew training. The enhanced flight control law incorporates angle of attack (AOA) inputs, limits stabilizer trim commands in response to an erroneous angle of attack reading, and provides a limit to the stabilizer command in order to retain elevator authority.
...
The FAA says it anticipates mandating this software enhancement with an Airworthiness Directive (AD) no later than April. We have worked with the FAA in development of this software enhancement.
It is important to note that the FAA is not mandating any further action at this time, and the required actions in AD2018-23.5 continue to be appropriate.
A pitch augmentation control law (MCAS) was implemented on the 737 MAX to improve aircraft handling characteristics and decrease pitch-up tendency at elevated angles of attack. It was put through flight testing as part of the certification process prior to the airplane entering service. MCAS does not control the airplane in normal flight; it improves the behavior of the airplane in a non-normal part of the operating envelope.
Boeing’s 737 MAX Flight Crew Operations Manual (FCOM) already outlines an existing procedure to safely handle the unlikely event of erroneous data coming from an angle of attack (AOA) sensor. The pilot will always be able to override the flight control law using electric trim or manual trim. In addition, it can be controlled through the use of the existing runaway stabilizer procedure as reinforced in the Operations Manual Bulletin (OMB) issued on Nov. 6, 2018.
...
A Boeing technical team is at the crash site to provide technical assistance under the direction of the Ethiopia Accident Investigation Bureau and U.S. National Transportation Safety Board. It is still early in the investigation, as we seek to understand the cause of the accident.