Illustration: Luo Xuan/GT
An Ethiopian Airlines Boeing 737 Max-8 crashed shortly after take-off, killing 157 people on Sunday. It was the second crash involving a Boeing 737 Max-8 within five months. The first involved Indonesia's Lion Air in October 2018.
Several countries suspect the reason for the two tragedies is the same - the automatic control system on this new model aircraft pushed the plane's nose down when its sensors recognized the plane was flying at a dangerous angle. Therefore, China's civil aviation regulator grounded the Boeing 737 Max series jets on Monday, becoming the first country in the world to order the ban.
If it can be concluded that the model's automatic control system caused both incidents, Boeing will face an unprecedented problem in its technology development.
The company has encountered difficulties in history. Some aircraft models were not readily accepted by the market many decades ago, and models such as the Boeing 307 and 377 had difficulties in business operations.
But the company and its airplanes have never suffered from setbacks due to technical flaws.
Boeing has technological advantages in the global commercial aviation industry.
The company has made great contributions to civil aviation safety by pioneering features such as cabin pressurization and an anti-icing system.
The tragedies offer a lesson for the Chinese civil aviation industry on the design of automatic control systems. We need to leave enough leeway to keep the automatic system running with minimum safety risk.
Even though the system receives mixed or wrong signals, it will not automatically push the flight into an irretrievable situation.
The difficulty with flight design is to select the right engine to match the aircraft. But the engine does not directly cause the crash.
Every manufacturer will tailor their control systems to the plane's features and parts. The key is whether there are enough contingency plans in place when matching the aerodynamic configuration to the control system.
Also, there must be flexibility for manual operation. If the automatic system malfunctions and renders control to the pilot, there has to be an interface informing pilots about the problem the system has encountered. This way, there's a better chance of the problems being fixed when the pilot takes over.
China's development of large passenger aircraft, symbolized by the C919, is just a beginning. There is a long way to go before its domestic civilian aviation sector can catch up to big name aviation companies like Boeing and Airbus.
More setbacks and frustrations are expected down the road of research and development for domestic aircraft due to the lack of experience. It will likely to encounter difficulties in commercial operations in the future as well.
But China's commercial aircraft development has proceeded cautiously with safety outweighing economic returns. Making safety a priority is an important feature in the development and operation of China's commercial aircraft.
China has its own path. Although we can borrow design experiences from other countries, China still sticks to the safe and sound way and carefully review them.
So, it may seem that Chinese commercial aircraft development is not progressing as rapidly as that in developed countries, but every step of the way has included judgment calls.
Many design schemes are put on the table. Every decision is a tradeoff. Designs with greater technological risks may lead to high commercial competitiveness, and vice versa.
This is a huge test for engineering and technical staff.
Aside from starting from scratch in designing the aircraft, they also give full consideration to ensuring there are no safety issues once the airplanes roll off the assembly line.
The Chinese civil aviation industry knows clearly where it stands. Instead of rushing, we need to make sure the C919 is a certified aircraft. Safety issues must come first.
Tweaks and improvements can then be made to its design to make it commercially successful.
That is the right path to follow.The author is the editor-in-chief at Aerospace Knowledge magazine of the Chinese Society of Aeronautics and Astronautics. [email protected]