A mourner of victims of the crashed Ethiopian Airlines flight reacts during the mass funeral at Holy Trinity Cathedral in Addis Ababa, Ethiopia, on March 17 2019. Picture: AFP/SAMUEL HABTAB
A mourner of victims of the crashed Ethiopian Airlines flight reacts during the mass funeral at Holy Trinity Cathedral in Addis Ababa, Ethiopia, on March 17 2019. Picture: AFP/SAMUEL HABTAB

New York — Flight recorder data recovered from the wreckage of Boeing 737 Max aircraft that crashed in Ethiopia and Indonesia show “clear similarities”, Addis Ababa said on Sunday as the US maker announced it is finalising a software update for its under-fire antistall system.

Pressure is mounting meanwhile on the US Federal Aviation Administration, which insisted it had followed standard procedures in certifying the aircraft model, even as it was reported to have come under investigation by the Department of Transport.

“The 737 Max certification programme followed the FAA’s standard certification process,” the agency said.

It said its procedures are “well established and have consistently produced safe aircraft designs”.

But reported similarities between the March 10 crash of an Ethiopian Airlines 737 Max 8, killing all 157 on board, and the Lion Air crash in October of the same model of aircraft in Indonesia, leaving 189 dead, have raised serious doubts and triggered Boeing’s biggest crisis in decades.

The 737 Max is a relatively new aircraft, having entered service only in May 2017 as Boeing’s answer to Airbus’s medium-haul A320 Neo.

Ethiopian transport minister Dagmawit Moges said on Sunday that a study of the flight data recorder retrieved from the Ethiopian aircraft has shown “clear similarities” to that of the Lion Air flight in Indonesia.

She said the parallels will be the “subject of further study”.

As investigators continue their work, preliminary findings in the Lion crash have focused on a possible malfunction of an antistall system known as the MCAS (maneuvering characteristics augmentation system).

Boeing developed that system, because of the unusually forward placement of the aircraft’s engines, to avoid a stall.

The manufacturer said on Sunday it is close to releasing a long-awaited software patch to the system.

Pilots complained

“While investigators continue to work to establish definitive conclusions, Boeing is finalising its development of a previously announced software update and pilot training revision that will address the MCAS flight control law’s behaviour in response to erroneous sensor inputs,” president and CEO Dennis Muilenburg said.

Experts have questioned the FAA’s certification process after learning that American pilots had lodged serious complaints about the system.

According to a Wall Street Journal report on Sunday, the FAA has come under an “unusual inquiry” by the department of transport over the issue, and has warned officials to safeguard computer files, according to sources quoted by the paper.

The journal said the probe will zero in on Seattle-area FAA offices. Boeing airliners are built near Seattle.

A Seattle Times report on Sunday read the FAA had delegated part of the certification process for the aircraft — including the MCAS — to Boeing engineers.

The original safety analysis provided to the FAA by Boeing contained “several crucial flaws”, the newspaper said, adding that the process was carried out hastily as Boeing struggled to catch up with Airbus’s more advanced work on the A320 Neo.

The report was dated 11 days before the Ethiopian Airlines accident, the newspaper reported.

The FAA refused on Sunday to comment on the newspaper reports, noting the various investigations still under way.

Defended practice

In the face of budget cuts, the FAA since 2009 has delegated some certification work to aircraft manufacturers or to outside experts, a procedure known as ODA (organisation designation authorisation).

On Sunday, the agency defended its practice, insisting that the 737 Max had to pass multiple tests and reviews before being authorised to fly.

It said the aircraft’s design was minutely examined, ground and flight tests were conducted, and other civil aviation authorities were consulted to ensure the “airplane complies with FAA standards”.

A statement provided by Boeing to The Seattle Times read that “the FAA considered the final configuration and operating parameters of MCAS during Max certification, and concluded that it met all certification and regulatory requirements”.

It said, without elaborating, that there has been “some significant mischaracterisations” of the certification process.

Peter DeFazio, chair of the House of Representatives’ transportation and infrastructure committee, is planning to launch an investigation into the 737 Max’s certification, congressional sources said.

Michel Merluzeau, an analyst at AirInsight, urged a cautious process.

“There may be a need to re-examine what works and what does not work [in the certification process] — but it should not be done emotionally,” Merluzeau said.

Another analyst, Richard Aboulafia of Teal Group, said the FAA’s credibility is at stake — “as is Boeing’s. And the global system of aircraft certification reciprocity is at risk too,” he said.