Seventeen months after the Boeing 737 MAX 8 entered service in 2017, Lion Air Flight 610, a relatively new 737 MAX 8 aircraft, crashed minutes after takeoff on 29 October 2018, killing 189 passengers and crew. Less than five months later, on 10 March 2019, Ethiopian Airlines Flight 302, also a 737 MAX 8 aircraft, crashed six minutes after takeoff, killing 157 passengers and crew. A total of 346 people have been killed in both accidents.

In reaction to the news of the Ethiopian Airlines crash, many airlines have grounded their Boeing 737 MAX fleets, either voluntarily or by order of their local aviation regulatory authorities. China was the first country to order all 96 of its Boeing 737 MAX aircraft grounded, with many other countries quickly following suit, while the US said that it had no basis to ground the MAX, despite mounting pressure from US senators and workers' unions.

While the cause of the Ethiopian Air flight crash has not yet been determined, and there is no evidence that the two accidents are linked, some journalists describe the aircraft behavior prior to the crash as similar to the Lion Air accident.

Timeline and context

On 29 October 2018, Lion Air Flight 610, a scheduled domestic flight operated by the Indonesian airline Lion Air from Soekarno–Hatta International Airport in Jakarta to Depati Amir Airport in Pangkal Pinang, crashed into the Java Sea 12 minutes after takeoff. All 189 passengers and crew were killed in the accident. It became the second deadliest airplane accident in Indonesia, only behind Garuda Indonesia Flight 152.

The Lion Air accident has been tentatively tied to the Maneuvering Characteristics Augmentation System (MCAS), a new system installed on the MAX 8 series. The design of the MAX 8 can cause the nose to pitch up higher than usual, which could lead to a stall. The MCAS senses the amount of lift on the aircraft's nose, and automatically adjusts the aircraft's attitude to lower the nose and avoid the stall. There was evidence that the MCAS had faulty sensor data regarding the aircraft's angle of attack.

On 10 March 2019, Ethiopian Airlines Flight 302, a scheduled international passenger flight operated by Ethiopian Airlines from Addis Ababa in Ethiopia to Jomo Kenyatta International Airport in Nairobi, Kenya, crashed six minutes after takeoff near Bishoftu, killing all 157 passengers and crew aboard the aircraft. It is the deadliest aircraft accident to occur in Ethiopia, superseding the crash of an Ethiopian Air Force Antonov An-26 in 1982, which killed 73.

Response

• Australia: The Civil Aviation Safety Authority (CASA) announced on the evening of 12 March that all 737 MAX aircraft in Australia or flying to Australia were grounded indefinitely. CASA's Chief Executive and Director of Aviation Shane Carmody announced that "This is a temporary suspension while we wait for more information to review the safety risks of continued operations of the Boeing 737 MAX".
• Canada: Minister of Transport Marc Garneau said it was premature to consider groundings and that, "If I had to fly somewhere on that type of aircraft today, I would."
• China: the Civil Aviation Administration of China ordered all domestic airlines to suspend operations of all 737 MAX aircraft operated by Chinese carriers pending the results of the investigation, grounding 96 aircraft, citing "zero tolerance for safety hazards".
• European Union: The European Aviation Safety Agency (EASA) released a directive on 12 March "suspending all flight operations of all Boeing Model 737-8 MAX and 737-9 MAX aeroplanes in the EU. In addition EASA has published a Safety Directive, effective as of 19:00 UTC, suspending all commercial flights performed by third-country operators into, within or out of the EU of the above mentioned models"
• India: Directorate General of Civil Aviation (DGCA) released a statement "DGCA has taken the decision to ground the Boeing 737-MAX planes immediately. These planes will be grounded till appropriate modifications and safety measures are undertaken to ensure their safe operations"
• Indonesia: the Indonesian Ministry of Transportation issued a temporary suspension on the operation of every Boeing 737 MAX 8 in Indonesia, 11 in all. A nationwide inspection on the type is expected to take place on 12 March to "ensure that aircraft operating in Indonesia are in an airworthy condition."
• Malaysia: The Civil Aviation Authority of Malaysia announced that they have suspended all Boeing 737 MAX flying operations from and to Malaysia, including transitting flights.
• Mongolia: Civil Aviation Authority of Mongolia (MCAA) said in a statement "MCAA has temporarily stopped the Boeing 737 Max flight operated by MIAT Mongolian Airlines from 11 March 2019."
• Singapore: the Civil Aviation Authority of Singapore, "The Civil Aviation Authority of Singapore (CAAS) is temporarily suspending operation of all variants of the Boeing 737 MAX aircraft into and out of Singapore in light of two fatal accidents involving Boeing 737 MAX aircraft in less than five months.
• Turkey: Turkish Civil Aviation Authority suspended flights of Boeing 737 MAX 8 and/or 9 type aircraft being operated by Turkish companies in Turkey, and stated that they are also reviewing the possibility of closing the country's airspace for the same.
• UAE: General Civil Aviation Authority (GCAA) issued a Safety Decision banning the operation of all Boeing 737 MAX models in the UAE airspace with effect from 13 March 2019, 00:01 UTC Time until further notice.
• United States: the Federal Aviation Administration (FAA) said they will assist the Ethiopian authorities investigating the crash but declined to ground the aircraft.
• United Kingdom: the Civil Aviation Authority (CAA) banned Boeing 737 MAX aircraft from operating in UK's airspace as "a precautionary measure". It had initially said in a statement "There are currently five Boeing 737 Max 8 aircraft registered and operational in the United Kingdom," "The US Federal Aviation Administration (FAA) is responsible for certifying all Boeing 737 Max 8 models and it is the European Aviation Safety Agency (EASA) that validates this certification across the EU, including the UK," and that "the CAA is working closely with the EASA".
• Vietnam: Civil Aviation Authority of Vietnam banned Boeing 737 MAX 8 flights in its airspace from 10 a.m. (local time) March 13, 2019, until further notice.

As a result of the Flight 302 accident, aviation authorities and airlines began grounding the Boeing 737 MAX due to safety concerns. By authorities (sorted by country):

China, Australia, Belgium, Bermuda, European Union (The European Aviation Safety Agency banned all 737 MAX aircraft models from its airspace starting at 19:00 UTC that day. The ban also applies in EFTA countries that are members of EASA, i.e. Liechtenstein, Norway, Switzerland, and Iceland),  France, Germany, Hong Kong, Indonesia, Ireland, Italy, India, Kazakhstan, Kuwait, Lebanon, Netherlands, New Zealand, Oman, Poland, South Korea, Thailand, United Kingdom, Vietnam.

By airline:

• On 11 March, in Argentina, in the wake of pressure from a pilots' union, Aerolíneas Argentinas on March 11 grounded its fleet of 5 737 MAX 8 for 72 hours. It had earlier indicated that it would continue to use the type and had formed a working group to review further developments.
• On 11 March, Brazil's Gol grounded its 737 MAX 8 fleet.
• A similar response was enacted by Cayman Airways, which suspended operation of its two 737 MAX aircraft until further notice on 11 March.
• Ethiopian Airlines, which operates four other Boeing 737 MAX 8 aircraft aside from the downed aircraft, announced that it had grounded its remaining 737 MAX fleet with immediate effect.
• On 12 March, Flydubai, which operates MAX 8 and Max 9 in its fleet, grounded its fleet to comply with the orders by the GCAA.
• On 12 March, Icelandair grounded all three of its Boeing 737 MAX 8 jets out of its fleet of 33 following the UK's CAA and Norwegian Air 
• On 12 March, India’s Jet Airways announced that they have grounded their 5 Boeing 737 MAX aircraft as of 12 March 2019. The airline stated that they are in contact with Boeing.
• On 13 March, India's SpiceJet suspends its Boeing 737 MAX 8 operations following the DGCA's decisions to ground the aircraft type in India.
• On 12 March, Aeroméxico has announced that they will be grounding their 737 MAX aircraft as of March 11, 2019. “For Aeromexico, the security of its operations and the peace of the customers are the most important. The flights operated with these aircrafts will be covered with the rest of the fleet.”
• On 12 March, LOT Polish Airlines grounded all five of its Boeing 737 MAX 8 jets.
• On 11 March, Mongolia's MIAT Mongolian Airlines grounded its one operating 737 MAX 8.
• On 11 March, Morocco's Royal Air Maroc voluntarily grounded its 737 MAXs.
• On 12 March, Norwegian Air temporarily grounded its Boeing 737 MAX 8 passenger jets, at the advice of European regulators, until further notice.
• On 11 March, South Africa's Comair grounded the only 737 MAX 8 in its fleet.
• On 12 March, Russia's S7 Airlines grounded 2 Boeing 737 MAX in its fleet.
• On 12 March, TUI Netherlands and Belgium ground every 737 MAX 8 in its fleet.
• On 12 March, Turkish Airlines grounded all 12 of its Boeing 737 MAX aircraft until further notice.
• On 12 March, Canada's Sunwing Airlines grounded every 737 MAX 8 in its fleet.
• On 13 March, Kazakhstan's SCAT Airlines grounded its only 737 MAX 8.

Few airlines expressed confidence in continuing to operate the Boeing 737 MAX:

• Air Canada continues to operate its 24 737 MAX 8 aircraft.
• American Airlines, which operates 24 737 MAX 8 aircraft in its fleet, released the following statement: "At this time there are no facts on the cause of the accident other than news reports" "We have full confidence in the aircraft and our crew members, who are the best and most experienced in the industry."
• Copa Airlines continues to operate its six 737 MAX 9 aircraft.
• Southwest Airlines, which operates 34 737 MAX 8 in its fleet, released the following statement: "We remain confident in the safety and airworthiness of our fleet of more than 750 Boeing aircraft." It is offering passengers scheduled to fly in a 737 MAX the opportunity to change their flights.
• WestJet, which operates 13 737 MAX 8 in its fleet, said in a statement, "We are monitoring the situation closely and will not speculate on the cause of the incident," and "WestJet remains confident in the safety of our Boeing 737 fleet including our 13 MAX-8 aircraft first introduced in 2017."
• United Airlines continues to operate its 14 737 MAX 9 aircraft as of March 13.

Manufacturer response

Boeing Commercial Airplanes, the manufacturer of the 737 MAX, released the following statement: "Boeing is deeply saddened to learn of the passing of the passengers and crew on Ethiopian Airlines Flight 302, a 737 MAX 8 airplane. We extend our heartfelt sympathies to the families and loved ones of the passengers and crew on board and stand ready to support the Ethiopian Airlines team. A Boeing technical team will be traveling to the crash site to provide technical assistance under the direction of the Ethiopia Accident Investigation Bureau and U.S. National Transportation Safety Board."

In a later response to the grounding of the aircraft, a spokesperson for Boeing released the following statement: "We have engaged our customers and regulators on concerns they may have – and would refer you to them to discuss their operations and decisions. Safety is our number one priority and we are taking every measure to fully understand all aspects of this accident, working closely with the investigating team and all regulatory authorities involved. The investigation is in its early stages, but at this point, based on the information available, we do not have any basis to issue new guidance to operators."

On 11 March, Boeing announced that it had been working on a flight control software upgrade to the MCAS flight control law, pilot displays, operation manuals and crew training. The upgrade, which Boeing said was partly in response to the Lion Air crash but not linked to the Ethiopian Airlines crash, will be deployed in the coming weeks and is expected to be made mandatory by an FAA Airworthiness Directive.

Political response

On 12 March, President Donald Trump spoke to Boeing CEO Muilenburg and received assurances that the aircraft was safe. He later tweeted, "Airplanes are becoming far too complex to fly. Pilots are no longer needed, but rather computer scientists from MIT. I see it all the time in many products. Always seeking to go one unnecessary step further, when often old and simpler is far better."

U.S. Senators Elizabeth Warren, Mitt Romney, Dianne Feinstein and Richard Blumenthal called for the FAA to temporarily ground 737 MAX 8. Elizabeth Warren accused the Trump administration of protecting Boeing, saying: "The Boeing 737 Max 8 is a major driver of Boeing profits. In the coming weeks and months, Congress should hold hearings on whether an administration that famously refused to stand up to Saudi Arabia to protect Boeing arms sales has once again put lives at risk for the same reason."

U.S. Transportation Secretary Elaine Chao said that "If the FAA identifies an issue that affects safety, the department will take immediate and appropriate action."