Questions galore as Boeing resumes production of 737 Max airplane

By Farouk Araie

Published: Sat 30 May 2020, 10:27 AM

Last updated: Sat 30 May 2020, 12:30 PM

The tragedy of Ethiopian Airlines Flight 302 is a year old but continues to dominate the aviation world.
There are flaws in Boeing 737 MAX, software systems that will have to be rectified. There are also hidden flaws in the composite structure of the airframe that must be rectified.
The 737 MAX is a commercial aircraft designed with fly by wire technology in order to ameliorate its performances in manoeuvrability both in the temporal and frequency domains. Nevertheless, the Achilles heel of these systems at this time is that the flexible dynamics of these airplanes have been mostly ignored when the software systems that control them were written. A phenomenon known as "spillover" is common in these rigid algorithms. By spillover, it is meant that commands between the current software and flexible systems there is always a tendency to overshoot or spillover when movements occur that were not expected.
What happens with fly-by-wire when the aircraft gets outside its control laws? It leaves pilots in a difficult situation. Humans tend to want simple answers to complex problems and to be able to ascribe blame to some single cause. There are, of course, other factors at work in these oversimplifications such as liability issues and misplaced faith in technology.
The introduction of any new aircraft entails problems of one kind or another. But the 737 extensive use of computers raises a new set of questions: are we ready to rely so heavily on complex software for such safety-critical applications as commercial flight?
The problem is that aircraft designers cannot anticipate all the possible demands the software would face.
Farouk Araie, Johannesburg, South Africa
 




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