‘Supervisor discovers problem with microprocessor in Boeing 737 Max tests’
The Federal Aviation Administration has discovered a new ‘potential risk’ in the Boeing 737 Max during tests with a flight simulator. According to CNN, it is an issue with a microprocessor, which could push the nose of the plane down.
CNN reports that government pilots have discovered a problem with a microprocessor during simulator testing, although it is unclear whether this contributed to the two previous deadly crashes of the Boeing 737 Max in Indonesia and Ethiopia. One of the pilots who tested the potential microprocessor problem says it was “difficult for test pilots to recover the aircraft in seconds.” He calls the inability to regain control of a device within seconds an “unacceptable risk”.
According to CNN sources, Boeing engineers are now investigating whether the microprocessor problem can be solved with new software, or whether the chips will all have to be replaced on every existing 737 Max aircraft. The New York Times reports that the test pilots indicated that the problem is very unlikely to occur during a regular passenger flight, but nevertheless the FAA believes that a solution should be found.
Boeing confirms that the FAA has filed a new requirement that Boeing should address “through the software updates the company has developed over the past eight months.” Boeing says it is working on the required software and that the 737 Max will not be offered for recertification with the FAA until all requirements are met. In addition, the FAA says it goes through a thorough process and does not adhere to a predefined timeline. Reuters says citing sources that the newly discovered problem means there will be no certification test flight until July 8 and the certification process is likely to be further delayed.
Final official conclusions will not follow until the ongoing investigations are completed, but it is currently believed that the two crashes of Lion Air and Ethiopian Airlines, which killed a total of 346 people, were caused by the MCAS system. This is a software system implemented specifically for the Boeing 737 Max that determines whether the aircraft is leaning too much backwards based on the angle of the aircraft in relation to the incoming airflow. MCAS is intended to prevent such a stall situation and can push the nose of the device down to prevent it. This happened several times during the two fateful flights, probably based on erroneous data from the angle of attack sensors. The pilots of both flights were unable to disable or circumvent the system in time and get their aircraft under control.