STORY: U.S. air-safety experts dispute at least two key findings of the Ethiopian investigation into the crash of a Boeing 737-MAX flight.
Flight 302 crashed shortly after take-off from Addis Ababa in March 2019, killing all 157 people on board.
The United States National Transportation Safety Board or NTSB says Ethiopian inspectors did not pay enough attention to crew training and emergency procedures in their report.
The accident led to the grounding of similar jets. The NTSB is involved because Boeing is a U.S. company.
Ethiopia's Aircraft Investigation Bureau released its long-delayed report on Friday (December 23).
It blamed the accident on "uncommanded" inputs from Boeing's Maneuvering Characteristics Augmentation System, known as MCAS.
The report said the inputs, which were caused by faulty data from an underlying sensor, sent the plane's nose down repeatedly, leading to a loss of control as the pilots tried to deal with several warnings in the cabin.
But in its comments, the NTSB said it found the faulty sensor may have been damaged by a bird strike soon after take-off, an assertion that was ignored by the Ethiopian investigators.
The NTSB also accused their Ethiopian counterparts of focusing on design issues at the expense of the crew's training and reaction.
In their report, the Ethiopian investigators found that the crew members were licensed and qualified for flight in accordance with the existing Ethiopian Civil Aviation Rules and Standards, but were startled by the unprecedented change of events and "confusing alerts", and blamed it all on the plane's design.
The accident involving Flight 302 followed another incident five months earlier, when the same model crashed in Indonesia, killing 189 people.
The crashes exposed a problem with a system on the plane, and the model was grounded worldwide, costing Boeing some $20 billion and prompting court cases that exposed shortcomings with the certification process.
Operators have since resumed flying the 737-MAX after the plane's 20-month grounding.
Ethiopia was among the last countries to return the 737-MAX to service.