The fatal airplane crash on Sunday involving a Boeing 737 MAX 8 operated by the Ethiopian Airlines has put Boeing¡¯s twin engine jet series under intense scrutiny worldwide. The reason? This is the second such crash involving the make within 5 months.
The impact of the crash was almost immediate on Boeing, with China and Indonesia ordering domestic airlines Monday morning to ground their 737 MAX 8 planes.
The reason for the blames is equally worrisome. It seems that a system that Boeing had added in these jets as a safety feature is going rogue. MCAS, or the ¡®Maneuvering Characteristics Augmentation System¡¯, essentially an anti-stall system installed in the aircrafts, is believed to be the most likely reason for the crashes.
So what is MCAS?
Boeing¡¯s new line of jets, the 737 Max, are an update to its hot-selling cakes, the 737. The MAX versions airplanes come with minimum design deviation from the regular line-up, except for the fact that the engines are placed further forward and higher on these.
This has its aerodynamic repercussions. As a correcting element, Boeing had to introduce the MCAS system in the line of jets. The system keeps the ¡°angle of attack¡± (angle between the wing and the airflow) in check. It responds when the angle-of-attack sensor indicates danger.
boeing 737 Max 8 (Representative Image: Reuters)
In such a case, the system automatically nudges the nose of the airplane downwards. The surprising (and a bit shocking) part here is that the system takes over even if the pilots are flying manually and not on autopilot. That is when the pilots are expected to address the potential stall issue.
US¡¯ Federal Aviation Administration (FAA) had issued an Emergency Airworthiness Directive around this earlier. It stated ¡°If an erroneously high single angle of attack sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer.¡±
It also mentioned the potential consequences of the discrepancy, ¡°This condition, if not addressed, could cause the flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain.¡±
So what happened in Ethiopia?
It is not known (yet). The MCAS might have played a major role in the crash, rendering the jet out of the pilot¡¯s control. But then again, it might not have. Further investigation is being carried out by both Boeing and the aviation authority of Ethiopia.
Ethiopian Airlines Flight ET 302 plane crash (Image: Reuters)
Boeing, however, is reeling under accusations that it failed to inform the pilots as well as the airlines of the new anti-stall controls. Boeing has been defending its take, saying the pilot manuals already contained instructions on how to override the automated system.
The extended problem
If a consistent issue with the Boeing 737 Max¡¯s anti-stall system is detected, a major challenge will be faced by aviation authorities and firms worldwide.
Why? Because MAX is Boeing's fastest-selling model yet. The company already had 5,011 orders of the jet at the end of January this year, while it has already delivered 350 since the jet¡¯s entry into service in 2017.
The grounding of these jets by aviation authorities, like what happened in China, can severely affect Boeing¡¯s business plans in various growing markets. More importantly, with little options to replace the jets to cater to the ever increasing number of fliers, the air commute across the globe might be largely impacted as well.
Update:?Brazil and Singapore?have followed suit and grounded their Boeing 737 Max aircraft. Airlines like Jet Airways in India have also grounded the plane.?Indian airline regulator (Directorate General of Civil Aviation) has also announced that only persons with 1,000 hours flying experience will be allowed to fly the Boeing 737 MAX aircraft.?
Civil Aviation ministry has ordered all Boeing 737 Max 8 operating in India to be grounded by 4 PM today.
A total of 13 countries have now banned the flight of the Boeing 737 Max.?
Boeing has released a statement, saying "The United States Federal Aviation Administration is not mandating any further action at this time, and based on the information currently available, we do not have any basis to issue new guidance to operators."