Investigators confirm Boeing 737 Max’s automated commands pushed nose down

The pilots of a 737 Max jetliner that crashed in Ethiopia in March struggled as the plane’s automated commands pushed the nose down, investigators said on Thursday in the first official word on the disaster that killed 157 people and sparked a crisis for plane maker Boeing  and aviation regulators.

The plane appeared “very normal” on takeoff and then suffered “repetitive uncommanded nose-down,” Ethiopia’s transportation minister, Dagmawit Moges, said in a news conference in Addis Ababa. The pilots followed all the safety procedures laid out by Boeing, she said, adding that the plane maker should review the system.

Ethiopian Airlines Flight 302 flew about six minutes on its flight from Addis Ababa before smashing into the ground, killing all aboard. Boeing has said it’s reviewing the report.

The crash was the second fatal accident in five months for Boeing’s top-selling jetliner, after a Lion Air aircraft plunged into the Java Sea in October and killed 189 people. The aircraft is now grounded worldwide as investigators probe its airworthiness and how it gained permission to fly. Thursday’s news conference presented initial findings after experts from Ethiopia, the US, France and the EU gathered in Addis Ababa to analyse cockpit voice and flight data recorders.

The 737 Max is the fourth generation of the world’s best-selling commercial aircraft. It includes a new feature, the Manoeuvring Characteristics Augmentation System, known as MCAS — the computerised antistall system that can push the plane’s nose. The system activated on the fatal Lion Air flight in Indonesia five months earlier.

Cpt Yared Getachew, in command of the Ethiopian Airlines flight, had amassed more than 8,000 flight hours, according to the airline, while first officer Ahmed Nur Mohammod had spent about 200 hours aloft.

There were people from 35 nations on board, including 32 Kenyans, 18 Canadians, nine Ethiopians and eight Americans. The UN, which was hosting an environmental conference in Nairobi, said it lost 19 staff members in the crash.

While Africa has a generally poor aviation safety record compared with global norms, Ethiopian Airlines is known for operating a modern fleet that features Boeing 787 Dreamliners and the latest Airbus SE A350, as well as the 737 Max.

The state-owned airline, Africa’s only consistently profitable carrier, has built Addis Ababa into a major hub feeding travellers from around the world into dozens of African cities in competition with rivals such as Dubai-based Emirates.Ahead of the report, some Ethiopians expressed pride in the airline, and a conviction that any blame would lie with Boeing.

“The mistake is in the software,” retired Col Tilahun Nebro, a former jet fighter pilot, said in an interview at an aviators’ club beside Bole International Airport, where the fatal flight took off.

Boeing and aviation regulators made a point of telling airlines worldwide how to disarm the system following the Lion Air disaster.

The crash has raised questions about the aircraft’s approval to fly. In the US, the Transportation Department has ordered a full audit of the Federal Aviation Administration’s 2017 certification of the Max and the justice department is also investigating.

Boeing has spent months refining the 737 Max’s software since data from the Lion Air crash indicated the stall-avoidance system had repeatedly tipped the nose down before pilots lost control. Boeing was close to a software fix when the Ethiopian Airlines jet went down.

Planes usually climb steadily to get safely away from terrain and to reach altitudes where engines burn more efficiently.

Instead, the Ethiopian aircraft twice descended briefly during the first two-and-a-half minutes after liftoff, according to tracking data provided earlier by FlightRadar24.com. The plane’s “vertical speed was unstable after take off”, the company said in a tweet.

Ethiopian Airlines earlier said that the plane’s pilots completed training recommended by the manufacturer and approved by the US Federal Aviation Administration before the Max fleet was phased in.

Boeing designed the 737 Max to deliver a 14% fuel-savings to compete with the A320neo from the company’s European rival, Airbus SE. The use of new, bigger engines required Boeing’s designers to mount the units farther forward on the wings in order to give them proper ground clearance when taking off or landing. That changed the flying characteristics in a way that the engineers thought required the additional system to prevent stalls.