An Ethiopian Airlines plane crashed minutes after taking off from capital Addis Ababa, killing all 157 people on board. It was the second fatal accident involving a Boeing 737 Max 8 aircraft in five months.
It is unclear why the plane, bound for Kenyan capital Nairobi, nosedived or whether the incident is related to last October’s Lion Air 737 Max 8 crash in Indonesia, which left 189 dead.
Boeing has confirmed that, for the past few months, it has been developing a “flight control software enhancement” for the aircraft, but says it is confident they are safe to fly.
Here’s what we know about the Ethiopian Airlines crash so far.
1. The accident happened shortly after take-off
The delayed flight ET302 took off from Ethiopian capital Addis Ababa at 08:38 local time (05:38 GMT) and was bound for Kenyan capital Nairobi.
It crashed 30 miles southeast of the airport, approximately six minutes into its two-hour flight, near the town of Bishoftu.
The flight had been due to depart at 08:15 local time.
2. The plane’s vertical speed appeared ‘unstable’
The cause of the disaster is not yet clear. But the pilot had reported difficulties and asked to return to Addis Ababa, Ethiopian Airlines has said.
Visibility was said to be good but air traffic monitor Flightradar24 reported that the plane’s “vertical speed was unstable after take-off”.
The pilot was named as Senior Capt Yared Getachew who Ethiopian Airlines said had a “commendable performance” with more than 8,000 hours in the air.
Investigators have found the cockpit voice recorder and digital flight data recorder but it will be a while before the findings are made public.
Following last October’s Lion Air crash in Indonesia, investigators said the pilots had appeared to struggle with an automated system designed to keep the plane from stalling, a new feature of the jet.
It is not yet clear whether the anti-stall system was the cause of the Ethiopian Airlines crash. Aviation experts say other technical issues or human error cannot be discounted.
Eyewitnesses say they saw a trail of smoke, sparks and debris as the plane nosedived.
3. Questions have been raised over a new automatic control system
After last year’s Lion Air disaster, Boeing issued guidance to pilots on how to manage the 737-Max’s new computer-controlled stability system.
The MCAS, which stands for Manoeuvring Characteristics Augmentation System, is designed to prevent the plane stalling when making steep turns under manual control.
A stall can happen when the angle at which the plane is flying gets too steep. This can reduce the lift generated by the wings, potentially making the plane drop.
To recover from a stall, a pilot would normally push the plane’s nose down. In the 737 Max, MCAS does this automatically, moving the aircraft back to a “normal” flight position.
The system continues to repeat the process if the computer detects the plane is still tilted at a too-high angle.
After the Lion Air crash, it was disclosed that the aircraft involved had experienced problems with a sensor which calculates the angle of flight.
CNN have reported that US-based 737 Max pilots have filed complaints about the performance of MCAS in flight, including reports of the system operating while autopilot is switched on, which should not occur.
4. The Boeing 737 Max is quite new
The Boeing 737 Max fleet of aircraft are the latest in the company’s successful 737 line. The group includes the Max 7, 8, 9 and 10 models.
By the end of January, Boeing had delivered 350 of the Max 8 models. They have been in commercial use since 2017.
The Max 8 that crashed on Sunday was one of 30 ordered as part of Ethiopian Airlines’ expansion. It underwent a “rigorous first check maintenance” on 4 February, the airline said.
A small number of Boeing’s Max 9s are also operating. The Max 7 and 10 models, not yet delivered, are due for roll-out in the next few years.
5. A number of countries have grounded the aircraft
The boss of Ethiopian Airlines has called for the grounding of all Boeing’s 737 Max 8 aircraft until it is established they are safe to fly.
The European Union and India are the latest countries or blocs to ban the plane from flying over their airspace to ensure passenger safety.
However, the US Federal Aviation Administration has declared the 737 Max 8 airworthy.
The Federal Aviation Administration said a review had showed “no systemic performance issues” and that there was no basis for grounding the aircraft.
The largest operator of 737 Max 8s in the US, Southwest Airlines, is offering passengers scheduled to fly on one of the Boeing planes the chance to change their bookings.
Rival American Airlines said its “standard policies for changes still apply”.