According to foreign media slashgear,Boeing's 737 MAX has been allowed to fly in the United States again, and the Federal Aviation Administration (FAA) has given the ill-fated jet a green light to fly back.The decision comes after 20 months of security review, after two incidents involving lion air flight 610 and Ethiopian Airlines flight 302, which killed 346 people.
The investigation identified a serious problem with Boeing's new 737 aircraft, including the 737-8 and 737-9. The system is designed to make aircraft control more consistent in unusual flight conditions, but the FAA found that in rare cases, the system can also override pilot input and cause a crash.
Compared with the earlier 737 models, the max engine is mounted higher and forward on the fuselage. Designed to improve fuel efficiency and other reasons, this will also cause upward pitching movement: in response to this situation, Boeing has installed MCAs, which can automatically fine tune the aircraft nose down whenever the 737 Max is in a steep turn or a low-speed flight with flaps retracted. In the process, it can help to avoid stalling. When the angle of attack reaches a certain threshold, the system designed by Boeing company can be started without informing the pilot.
consequences were rapid ,737 MAX grounded worldwide and investigated the incident several times. While FAA may have cancelled the suspension, it does not mean that 737 MAX will take off from airports across the United States immediately. Rather, there is a new airworthiness directive detailing the design changes that all 737 MAX aircraft FAA say must make to successfully lift the stop.
In addition, there is a notice of continued airworthiness of the international community (canic) and a set of Max training requirements. The latter specifies the pilot training programs that any 737 Max operator needs to complete before taking control. The FAA will approve any such plans by American Airlines.
the revision of the 737 MAX includes redesigning the MCAS operation mode, especially its working mode with the angle of attack (AOA) sensor. before, only data from one sensor can be triggered MCAS; now, data from two sensors will be compared and must be matched before triggering.
Boeing said the MCAs itself would now only be activated once, "and will never provide more input than a pilot can counter using the stick alone.". The pilot will also be able to cover it at any time, as before. Boeing said the flight control computer software has been adjusted, adding more cross checks between different flight control computers, and lines in some places have been adjusted to increase space.
Aircraft that have been grounded since the first implementation of the aviation order must now undergo a series of necessary maintenance steps before they can fly again. Aircraft that have not yet been delivered are subject to FAA face-to-face review before obtaining an airworthiness certificate.
At the same time, Boeing has established a new product and service safety department, which is composed of more than 50000 engineers, focusing on "unifying the safety responsibility of the whole company".