Boeing redesigned its Boeing 737 to Boeing 737 Max by changing engine and air intake design to increase fuel efficiency to compete with Airbus. It resulted in stall condition during flight. To overcome the stall condition, Boeing modified the flight control software . The software takes the control of aircraft from pilot during stall condition and nose up due to shifting of C.G. But, Boeing did not perceived that in case of wrong feedback of angle of attack, computer will give wrong input. The nose of the aircraft will lowered down and further wrong input will result in stall condition and nose down. In such case pilot will not be able to understand the emergency and by the time he tries to take over in manual mode, aircraft will go out of control resulting in further nose down and crashing of aircraft.
Why Boeing could not assess this risk being pioneer in risk based thinking ( being one among the prime contractor and member of IAQG) ?
Very good analysis.
Boeing not very sure about they sensitivity of Stability augmentation system i guess. Hope the investigation concludes some valid reason
Working for the FAA as a research scientist, I have some insight into situations like this (although please do not consider my comments as official FAA statements; they are simply my own personal observations).
Modern aircraft are so enormously complex that virtually no one on the development team knows every detail about every component. Software "fixes" are sometimes employed to address engineering challenges, as was the case here. However, programmers may not fully understand the ramifications of code changes on engineering and human factors. Simultaneously, engineers may not fully understand the ramifications of engineering changes for human factors and programming. Lastly, human factors psychologists may not fully anticipate the ramifications of engineering and code changes on pilot performance and training needs. The science of aircraft development has evolved into at least three separate specialty areas, each of which doesn't fully understand the other two.
This will inevitably lead to instances where an engineer may assess the reliability of, say, an attitude sensor at having such a high level that redundancy is considered unnecessary. Or, programmers may talk to engineers and work out a fix for a center-of-gravity or thrust issue,, but neither may be aware of human-factors issues such as delayed feedback oscillations and the need to modify pilot training to address low-probability-high-impact contingencies.
I am not suggesting that these examples are necessarily what caused the 737 Max problems. All I'm saying is that the increasing complexity of modern aircraft, in combination with the increasing specialization of the people who work on them, is bound to lead to situations where hazards become apparent during field operation rather than being recognized and addressed during the development stage
I personally think, the pressure to release a product was way above normal levels. As the FAA was (is) not properly funded by state money, they started deligating certification tasks to delegated personnel from Boeing. In older times they were reporting directly to the FAA, so they were kind of independent from the Boeing management, although they were paid by Boeing. This changed, the delegated person is now reporting to the Boeing management, witch put a lot of additional pressure on the delegated person to release something that is perhaps not tested properly.
The first thing that needs to be evaluated is their (Boeing) Safety Management System (SMS) and the Safety Risk Management (SRM) study which should be conducted without the economic pressures of getting a new product released. The FAA doesn't have enough personnel to do an independent risk assessment, but if Boeing truly wanted an objective assessment they would have included operators, regulators, internal and external engineers to look at this change.
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