Ethiopian Airlines accident report and software solution Boeing 737 Max expected: NPR

Boeing announced Wednesday that it has developed a software patch for its 737 MAX aircraft, which will be unveiled Wednesday to authorities, pilots and aviation authorities around the world, as the aircraft manufacturer seeks to reinstate the customers and the public in the air as a result of two fatal accidents. planes in the last few months.

Meanwhile, these collisions and relations between Boeing and the federal agency responsible for regulating it will be discussed at a hearing of the US Senate Subcommittee on Aviation to be held Wednesday. The Chiefs of the Federal Aviation Administration and the National Transportation Safety Board, as well as the Inspector General of the Transportation Department, will investigate how the FAA has certified the 737 MAX as being seaworthy, and on whether regulators relied too much on Boeing's own safety assessments when they were examined.

These developments come as the transport authorities in Ethiopia prepare to release preliminary findings on the cause of an Ethiopian Airlines Boeing 737 MAX 8 crash earlier this month, which killed 157 people on board.

A spokesman for the Ethiopian Ministry of Transportation told the Associated Press that "a date has not yet been set but that (the preliminary report) will be released later this week". The spokesman said the US National Transportation Safety Board, the BEA, the French authority in charge of investigations in the aviation sector, and the Ethiopian Ministry of Transport are conducting the investigation jointly.

Investigators said that there were striking similarities between the March 10 crash in Addis Ababa, capital of Ethiopia, and the crash of a Lion Air Boeing 737 MAX 8 in the sea of Java, Indonesia, last October. Both aircraft crashed shortly after take-off and both followed similar irregular flight paths, indicating that pilots may have difficulty trying to prevent the aircraft from sinking into the dive.

During the crash of the aircraft Air Lion on October 29, which killed 189 people on board, Indonesian investigators said that an automated flight control system, acting on erroneous data provided by a defective sensor, had repeatedly forced the nose of the aircraft. This system, called MCAS (Maneuverability Enhancement System), is designed to prevent the aircraft from taking off. But the Lion Air pilots apparently did not seem to know how to thwart the system or disengage it, and were fighting in vain to regain control of the plane.

After the Lion Air crash, many pilots complained that they had not been informed of the MCAS system, as it did not exist in previous versions of the 737, nor had they been trained in what to do when the system engages and forces the nose of the plane down unexpectedly.

It is still unclear whether something similar has happened on board the Ethiopian Airlines aircraft, but the company's CEO said the pilots had been trained in the management of the new system after the Lion Air crash.

Boeing officials said the company had finalized the development of software upgrades for MCAS to prevent such incidents in the future. The system will act more repeatedly by forcing the nose of the aircraft and will only act once it detects the aircraft entering an aerodynamic stall. And the MCAS system will rely on data from both aircraft angle attack sensors, instead of just one.

In addition, a light warning the pilot that angle of attack sensors will not agree will become the norm instead of becoming a more expensive option for airlines and will be added free of charge to the entire fleet. 737 MAX devices.

A Boeing official said that software upgrades had been extensively tested in the lab and on simulator, pilots of a simulator facing a series of errors and malfunctions, including sensor errors and other erroneous entries.

The Boeing official said the FAA had participated in the assessment, and had even introduced the software upgrades during a test flight on March 12.

It is unlikely that the FAA will act swiftly to certify software upgrades and other patches, especially given the scrutiny of the certification process from Congress and others. And regulators in Canada, Europe, China and other countries say they will no longer depend on FAA data and will run their own tests of MCAS software updates before allowing 737 MAX aircraft again of Boeing flying in the air. As a result, some experts believe that the return to service of the aircraft could take months.