departure from Jakarta on October 29 , 2018 . A total of 189 people died in that crash . The aircraft was quite a new Boeing B737MAX model delivered to Lion Air on August 13 , 2018 . The crash was not due to bad weather . Both the captain and co-pilot were experienced aviators and had thousands of flight hours . Boeing initially announced that B737MAXs were safe to continue flying and issued several documents for operators to advise pilots to act upon should they encounter similar aircraft nose pitching issues . Airlines and operators continued to operate the B737MAX , commuting the public regionally and internationally . However , the world had another shock with the crash of another B737MAX . Ethiopian Airlines flight ET302 crashed six minutes after take-off , killing all 157 people onboard . The two crashes of the same aircraft model in five months caused the aircraft to be grounded for further technical investigations . The data extracted from the flight data recorders displayed similar flight patterns prior to the crash . In both cases , the horizontal stabiliser ( pitch ) appeared to be uncontrollable to avert the crashes .
In the final report released by the US National Transportation Safety Board ( NTSB ), several issues were identified by the independent investigation committee . For discussion purposes , I will focus on the issue of ethics based on my observation of the final report . The report cited Boeing ( and some engineers ) for ethical issues that led to the crashes that killed a total of 346 passengers instantly with both the aircraft plunging to the ground at a speed of up to 1100km per hour .
In the rush to be competitive with Airbus A320NEO and avoid financial and market share reduction , Boeing did not design a new Boeing B737 with improved performance and efficiencies . Instead , Boeing decided to modify the existing B737NG with bigger and more powerful engines mounted slightly forward of the existing engine pylon and with a slight upward tilt to ensure that the engine had sufficient ground clearance . This had a significant impact on the aerodynamic characteristics of the plane , with a high tendency for the aircraft to pitch up during high engine power . Continuous pitch-up causes the aircraft ’ s aerodynamics to stall , which is dangerous due to the loss of lift on the wings , and may cause the aircraft to potentially crash .
The engineers had to overcome this issue with the use of a horizontal stabiliser control that has a strong effect on the pitching of the B737MAX through software loaded into its flight control computer , which controlled the horizontal stabiliser movement .
However , the design of the flight control software , known as the Manoeuvring Characteristics Augmentation System ( MCAS ), had flaws when activated to execute the stall prevention system on the aircraft . It appeared that the software was written whereby it only required “ one ” angle of attack ( AOA ) sensor to activate the MCAS system which would brutally override the pilot ’ s command and keep the aircraft pitched down during a stall condition . Relying on a single AOA sensor did not meet the redundancy requirements of the design standards of an airplane . In both crashes , there was only one faulty AOA sensor sending a false impending stall signal to the flight control computer which pushed the nose down repeatedly until the aircraft crashed . The pilots were fighting with the aircraft to gain pitch control but the MCAS “ overpowered ” the pilots , resulting in the crash . Instead of solving the original pitch-up tendency problem , the MCAS created another problem . How could this be missed out by the engineers ? Even if this problem was raised by some of the engineers to the corporate level , did the senior management accept and initiate corrective actions even if they meant potentially delaying the production schedule ?
It was found that there was no algorithm embedded for cross-checking the AOA left sensor to the right sensor before activation of MCAS . Should the airline or operator opt for a second sensor , the airline or operator would have to pay for it . Safety for sale ? Trading safety for financial gain in engineering services was never a guideline in any practice of engineering professionalism . Based on some of the reports that I read , accidents continue to happen when financial gains take priority over professional engineering services , ignoring the priority of safety . The AOA sensor was faulty but the MCAS system was designed to command the pitch control of the aircraft . The pilots were not able to override the system except by selecting the stabiliser cut-out switches to cut out the power to the horizontal
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