Boeing 737 MAX 8: Why the aircraft is being banned by multiple countries after two crashes in five months

India on Tuesday night joined an increasingly large list of countries that have banned the under investigation Boeing 737 MAX 8 aircraft which has befallen two fatal accidents over the last five months, leading to the tragic demise of a total of 346 people including passengers and crew.

While it is not yet completely clear why or even if the twin crashes are directly related to a possible flaw in the aircraft, here's what you need to know about the entire matter as it stands at the moment:

The Boeing 737 MAX 8:

This variant of the aircraft only commenced delivery in 2017 - very recently in aircraft terms - but comes from pedigreed lineage. The 737 series has been one of the most popular narrow-body short- to medium-range twin-engined aircraft for decades with regular and significant upgrades being made at various points to ensure its longevity and continued technological competence. It competes with the Airbus 320 line which essentially falls into the same category, with the most recent variants focusing on efficiency and gaining huge orders as a result. The engines for the Boeing 737 MAX line are made by CFM International - an equal JV between GE Aviation of the US and Safran Aircraft Engines from France. Over 350 deliveries of the Boeing 737 MAX line have been completed so far and Boeing's order book has orders for over 5000.

The two crashes:

The first crash of the plane variant in question - the Boeing 737 MAX 8 - took place on October 29, 2018, in Indonesia as Lion Air flight 610 crashed into the Java Sea just 13 minutes after take off from Jakarta's Soekarno-Hatta International Airport, killing all 189 people on board. It was the first fatal accident involving a 737 MAX.

The second crash took place on March 10, 2019, as an Ethiopian Airlines flight 302 crashed six minutes after takeoff from Ethiopia's capital Addis Ababa. It was heading towards Kenya's capital Nairobi. All 157 people on-board perished, including four Indians. The plane was only four months old.

Circumstances of the crashes:

There are more known details of the first crash than there are of the second at the time of publishing, and not only because the latter happened mere days ago.

As per reports, the specific Lion Air plane had in the immediately preceding flights recorded abnormalities regarding its altitude vs air-speed data, with those aboard the plane concurring. 

When it crashed, eyewitnesses at a nearby offshore oil platform claimed that the plane had hurtled steeply nose-down when it had crashed, and post-crash evidence has indicated that the engines were still running when it crashed. Immediately before the crash, the flight crew had sought to return to Jakarta airport, as per reports.

In the case of the second crash as well, the pilot asked to return to Addis Ababa minutes after takeoff. As per data, there was again an abnormality in the aircraft's altitude and air-speed - the two are tied together in aviation physics, along with a number of other factors.

What experts are saying regarding why the crash took place:

With a report into the first crash's investigation only expected later this year - a reason why the plane has been banned from the air-spaces of numerous countries - experts, drawing from the circumstances of the two crashes, are postulating that the flaw - if at all - is linked to a mainly-software system on Boeing 737 MAX aircraft that is meant to prevent the plane from stalling in case of a dangerous airspeed condition. It reacts by changing the plane's nose orientation, possibly overriding the pilot's own controls.  

What has not yet been determined is whether the airspeed-altitude abnormality was real or a faulty output from a sensor precipitating a response from the software system, called the Maneuvering Characteristics Augmentation System (MCAS). Boeing said on March 11 that it is in the process of issuing a software upgrade in response to the Indonesia crash but not linked to the Ethiopia crash. 

What India and other countries have done:

India has grounded Boeing 737 MAX planes till appropriate measures are taken, as the DGCA's tweet says:

A EU agency has closed European airspace to Boeing 737 MAX aircraft. France, Britain, Ireland, Iceland, the Netherlands are among countries who have banned Boeing 737 MAX airplanes from their airspace. Turkish Airlines has halted flights using Boeing 737 Max planes.