Keeping the MAX flying

Sci Tech Sep 13, 2020

On 10th March, 2019, an Ethiopian Airlines’ flight starting from Addis Ababa, carrying 157 people, crashed into a nearby village, barely minutes after takeoff, killing everyone on board. This was just a few months after another flight, Lion Air Flight 610, crashed, once again, just after takeoff, into the Java Sea, off the Indonesian coast, killing 189 people in the process. Both these flights were operating the same aircraft, the Boeing 737 MAX 8, the newest version of the most popular single-aisle aircraft ever known, the Boeing 737. There is nothing that is particularly wrong with this engine; in fact, manufacturers raced to put them on their airplanes, and that is where their troubles began.

The two biggest airplane manufacturers in the world are Airbus and Boeing, and their rivalry means no bounds; if one can offer a better bet on a plane, the other stands to lose billions of dollars. That is exactly what was about to happen in 2010 when Airbus announced that they were going to update their most popular model, the A320, a single-aisle airplane. You’ve probably even been on one. Airbus had a big update - it was going to have a new kind of engine, much larger than before, but also 15% more efficient than the outgoing model. It wasn’t going to differ from the old A320 by much. A pilot from the old model could just walk in with minimal training and be on their way. Called the A320-neo, this airplane stood to save a lot of money for its potential buyers.

In the meantime, American Airlines announced an order for a re-engined version of the Boeing 737. The pressure that this brought about on Boeing, forced it to choose between the easy wrong and the difficult right. Assuming that they could re-engine a 50-year-old design at the time, they went ahead and decided to update the engine on their most popular single-aisle jet.

The 737’s design limitations meant that a bigger engine wouldn’t fit as easily under the wing as it did on the A320-neo, but Boeing was in no mood to give up. They soon came up with an innovative solution, to push the engine up on the wing such that it would fit in.

Boeing called this model the 737 MAX. Just like Airbus with the A320-neo, they said that this model was so similar to its predecessor that pilots would need only minimal additional training. Thus, it became a hot selling aircraft in the market within a year of its introduction. Except that moving the engine up had a side-effect. When in full thrust, like during takeoff, the nose tended to point too far upward, which could lead to a stall. This was a problem because these planes were supposed to behave exactly like the outgoing model. So Boeing had to come up with a solution.

Instead of re-engineering their aircraft, they installed software that automatically pushed the nose down if the pilot flew the plane at steep angles. They called it the Maneuvering Characteristics Augmentation System, or MCAS. However, because Boeing was selling the plane the same as the previous generation of 737’s, they failed to highlight the new MCAS system, and most pilots received insufficient training before entering the cockpit for the first time.

Two years after its introduction, several pilots complained to the Federal Aviation Administration (FAA) of the USA that the plane was suddenly nosing down while in flight. On the morning of 29th October, 2018, Lion Air Flight 610 took off from Jakarta. In the flight report, it was stated that the plane was at full thrust during takeoff but with its nose lurching downward. Unable to decipher the reason behind this, the pilot and the first-officer referred to the quick-reference handbook, but to no avail. The pilots put up a valiant struggle against the MCAS, but in the face of rapidly falling altitude, it was insufficient. Reports suggest that it was likely that the on-board computers were receiving incorrect sensor data, pushing the plane toward the earth below and 12 minutes after takeoff, the plane crashed into the Java Sea.

The Ethiopian flight faced a similar scenario, only this time, the pilots did manage to overcome the malfunctioning MCAS sensors, but it was too little, too late. As a result of these crashes, nearly 700 of the 737 MAX jets stand grounded today and the FAA is facing scrutiny over how they rushed this plane through certification.

What has changed?

Boeing says that the MCAS system has been modified to accept dual input from its sensors while limiting its activation to only once per takeoff. What’s more is that the pilots’ dashboard has been retrofitted with warning lights for the MCAS and greater clarity on the system has been assured.

The FAA completed its first recertification flights in July this year. Since then, the EASA has also followed suit and are in the process of completing their own flight assessment. The Joint Operations Evaluation Board (JOEB) comprising several regulators (unfortunately, excluding India’s own DGCA) is in the process of releasing a report highlighting their findings from the recent flights, whilst allowing for public comments and suggestions.

Merely recertifying an aircraft with such a record back into service is insufficient. It will take more than assurances to restore lost trust. In light of this, Boeing seems to be considering several options. Recent reports suggest that there has been an effort to rebrand the aircraft as the Boeing 737-8 or 8200, in an effort to try and rebuild some face. However, it remains unclear if this is a product-wide change or merely an airline-specific move.

With respect to India, the fact that the DGCA has maintained an uneasy silence on this issue while also not actively engaging with the JOEB or working towards re-evaluating the aircraft is concerning. When the aviation sector does return to normalcy in a post-COVID world, carriers like SpiceJet that fly this aircraft would look favorably on the aviation regulator to lead the charge in rebuilding the lost ground.

For what is considered among the safest and most aspirational ways to travel and see the world from the skies above, this aircraft’s tale is one that compromises on the former, for reasons aplenty. Mankind’s dreams cannot take off without placing a heavy price on the lives that seek to live it. The cost of failing to do so is thus evident.

The author would like to thank Mr.Madhav Pai, an aspiring pilot, for his valuable inputs in writing this article.


N Krishna

You may know me as the guy who talks and writes like a sergeant, is an av-geek and works out obsessively, but not as one who laughs with a full heart and cooks like it’s an experiment.