The 737 MAXs have been discontinued since March after the Ethiopian Airlines crash, Boeing initially promised to bring the aircraft back to the sky in just a few weeks with software upgrades but so far. By the end of 2019, 737 MAX's "return" is still far away and this deadline is continuously pushed back. What is hindering the recovery progress of 737 MAX?
According to Bloomberg, the unsuccessful simulations in the 737 MAX's simulator chamber in June forced Boeing to redesign the software, thereby lengthening the return of the aircraft's sky.
737 MAX had two accidents in just 5 months, the first of which was the Lion Air JT610 that fell into the Java Sea just 13 minutes after taking off in October 2018, followed by the Ethiopian Airlines ET302 crash in March. after taking off from Addis Ababa, Ethiopia. 2 accidents killed 346 people. Boeing then released a software update In order to prevent the MCAS system from automatically activating the wrong situation, all 737 MAXs in the world are still suspended under the FAA decision and many aviation management agencies in the world. MAX 737 was taken back to Boeing's factories and so much so that the airline had to park the plane in the parking lot for employees.
Boeing initially said it could develop and apply a new software patch to the MCAS system within weeks. Then Boeing announced a few months back so it could fully test and standardize the software.
What is MCAS? It is a software designed by Boeing to automatically adjust the status of the wings on the 737 MAX to compensate for the "volatile" characteristics of the 737 MAX. The 737 MAX has a new, larger engine and the engine placement is different from the older 737 models, so this aircraft tends to raise its nose high and at large angles of attack (like when taking off), it more and more prone to losing power lift, MCAS will now intervene, automatically adjust the horizontal stabilizer wings to bring the aircraft nose down.
However, because it only works based on a tonnage sensor instead of 2 so if the data from this sensor is wrong, MCAS will trigger it wrong and the pilot will be hard to know what is happening. because they themselves are not trained on how to handle when MCAS activates. Even many pilots do not know the existence of MCAS. All because of cost, Boeing wants to promote the 737 MAX as a variant of the 737 with the same aerodynamic characteristics, from which the airlines do not have to spend money to retrain pilots while the 737 MAX series carry more and save more fuel. In fact, 737 MAX and previous 737 generations such as 737 NG are no longer the same despite the same exterior design.
However, in June, when Boeing engineers had almost completed the design of the new software patch, Boeing test pilots stepped into the simulator to test it. The result is a computer malfunction in the simulation chamber caused the aircraft to bow out of control same as the state of 2 737 MAX 8 in 2 accidents.
Flight simulation saw failure causing Boeing to redesign the flight management computer architecture on the 737 MAX and the time to fly back of this plane continued to be delayed, lasting through the summer, now arrived. and threaten the ability to deliver aircraft, place new orders and maintain Boeing revenue.
Software redesign also led to delays in obtaining flight permits from FAA as well as global aviation authorities. They are reviewing each change on the 737 MAX software more closely and require Boeing to update information regularly.
The initial fix focused on the MCAS system, but after the second crash the issue was expanded, such as how the pilot responded to many cockpit alarms and what would happen in situations. both common and rare emergencies.
In a test that made Boeing decide to redesign its computer architecture, Boeing tested the operability of the 737 MAX in the event that gamma rays from space ruined data on the flight control system – a situation. very rare but this is something that Boeing wants to solve in order to prove the safety of 737 MAX before the managers.
As for the June test, the nose-bowed plane and one of Boeing's pilots reported that it was difficult for him to respond to many warnings and system failures in time to control the aircraft.
Although the 737 MAX had two computers, one that controlled flight control systems, the other was in standby mode and only operated when the other was broken, now Boeing has restructured to get both monitors on. each other. The initial setup was considered obsolete, borrowed from the older 737 generations and this change was in line with the more modern aircraft design trend. Hopefully Boeing has learned a great lesson and the airline will bring the 737 MAX back and become "one of the safest aircraft in the world" under the commitment of John Hamilton – Boeing technical director: