737 Max comes back to the sky. Will Boeing have a run of good luck? Part 4

Chinese state corporation COMAC elaborates short-haul narrow-body airplane C919 since 2008. It is direct competitor of Boeing 737 Max and also of the European A320 and Russian MC-21.

On December 4th Civil Aviation Administration of China (CAAC) authorized beginning of certified tests C919. Authorization means that regulatory authority is satisfied with configuration, construction and airplane’s systems. COMAC intends to get Chinese certificate in 2021.

In European Union and Russia where are manufactured or are being prepared to be manufactured competitors of Boeing 737 MAX unlikely will appear difficulties in returning this airplane to the sky. On Russian market there are two units of Boeing 737 Max – in the fleet of S7 airline company.

The root cause of the crises of 737 Max program became confrontation of Boeing and its’ competitor Airbus. When European corporation declared launch of the new model of medium-haul airplane A320 with fuel-efficient engines, Boeing decided to renew its’ airplane in this class – 737. Thus appeared new series of this family under the name Max.

However due to constructional features of the airplane engines had to be lifted up – closer to the wing. This caused that the airplane got tendency to “pitching nose up”. Such airplanes’ behavior in the air had to be corrected somehow because uncontrolled nosing-up may cause loss of speed and this may lead to stalling.

So in the onboard digital computer was installed program that helped pilots “steering up” the airplane, correcting its’ position in the air and directing it a little down. This system is called Maneuvering Characteristics Augmentation System (MCAS).

As it was found out afterwards this program in case of wrong actuation of angle-of-attack transmitters directed the airplane to land not allowing pilots to change its position. Namely because of this program two air crashes took place from which deep crises of aviation giant began.