Within hours of the Ethiopian Airlines crash on Sunday similarities were already being drawn between it and Lion Air Flight 610, another Boeing 737 MAX 8 that crashed in October last year, killing all 189 onboard.
This latest crash that killed 157 marks the second in six months, causing concern among operators of the model, which is a 2017 update of Boeing's most successful regional jet.
While the black boxes and flight records from Sunday's air crash are being examined, several countries have taken the precaution to ground the aircraft. As of Tuesday this includes Australia, Britain, Singapore, Malaysia and Oman while Ethiopia, China, France, Ireland, Germany and Indonesia have issued temporary suspensions on flights using MAX plane models.
New Zealand is one of a handful of countries that has not banned the plane from its airspace.
The USA is another notable inclusion on the list allowing the planes to continue operating. Their maker, American-owned Boeing, has seen company value hit. But the continued operation of the 737 MAX in US airspace can be seen as a vote of confidence.
The main airlines are in denial of a link between the Lion Air and Ethiopia Airways incidents. American Airlines and Southwest, which operate 750 Boeing aircraft, remain confident in the aircraft and see no need to ground their fleets, with the former saying that it had "no facts on the cause of the accident other than news reports" and that they have "full confidence in the aircraft and our crew members, who are the best and most experienced in the industry".
Ultimately, it is the US FAA (Federal Airspace Authority) that is responsible for granting permission for the MAX to fly in American airspace and first assessed the plane's airworthiness in 2017. On Monday the FAA said it "had not been provided with any information that would draw similarities between the incidents in Indonesia and Ethiopia," as reported in the Chicago Tribune.
Who still uses the plane in New Zealand?
Air New Zealand no longer flies Boeing 737s on its domestic and short haul operations.
Airlines in New Zealand using the aircraft include Fiji Airways, which flies 737 MAX services out of Wellington, Christchurch and Auckland. A spokesperson for the airline told Newstalk ZB that Fiji Airways had "full confidence in the airworthiness of our entire fleet" and that their pilots and crew received training "above the mandated level set for the MAX 8 by the manufacturer".
Virgin Australia currently operates an older model of the 737s in New Zealand but has 40 MAX 8 planes on order from Boeing.
What are the chances of flying on a 737 MAX?
There are about 350 jets in operation across 54 airlines. Outside of the 58 jets in use in the States, there are 24 belonging to Air Canada, 18 flying for Norwegian, 13 for WestJet and just three flown by Icelandair. According to CNN the largest number of these are in China, with China Airlines, China Eastern and China Southern recently buying 97 MAX 8s.
What has Boeing said?
In two statements issued over the past 24 hours the aircraft manufacturer has said that the FAA has ordered a software update for the MAX aircraft model, and that "safety is Boeing's number one priority".
With regards to the software update, Boeing referred to it as an "enhancement" that is "designed to make an already safe aircraft even safer".
Outlined in the March 11 statement were "updates to the Manoeuvring Characteristics Augmentation System (MCAS) flight control law, pilot displays, operation manuals, and crew training. The enhanced flight control law incorporates angle of attack (AOA) inputs, limits stabiliser trim commands in response to an erroneous angle of attack reading, and provides a limit to the stabiliser command in order to retain elevator authority."
The FAA has mandated the software improvements to be in place no later than April this year.
What are the similarities between Lion Air and Ethiopian Air crashes?
Both accidents happened within 15 minutes of takeoff.
Flight recordings are still awaited for the Ethiopian Airlines plane, an investigation into the Lion Air crash shows "faulty sensor readings" to be a cause.
The investigation by Indonesia's National Transportation Safety Committee found that "pilots struggled to keep the nose of their Boeing 737 Max 8 plane up" shortly before the crash in October.
Investigators of Sunday's crash will be assessing the recovered black boxes to see if it suffered from similar faulty sensor readings.