Boeing issued a software update for 737 MAX aircraft in order to battle the software problem in controversial MCAS (Manoeuvring Characteristics Augmentation System) anti-stalling system.
However, Boeing has not hinted when the aircraft will fly again as airlines around the world are awaiting for the safety approval.
Boeing has redesigned the software so that it will disable MCAS if it receives conflicting data from its sensors.
As part of the upgrade, Boeing will install an extra warning system on all 737 Max aircraft, which was previously an optional safety feature.
Boeing statement about the software update for MCAS system:
The Maneuvering Characteristics Augmentation System (MCAS) flight control law was designed and certified for the 737 MAX to enhance the pitch stability of the airplane – so that it feels and flies like other 737s.
MCAS is designed to activate in manual flight, with the airplane’s flaps up, at an elevated Angle of Attack (AOA).
Boeing has developed an MCAS software update to provide additional layers of protection if the AOA sensors provide erroneous data. The software was put through hundreds of hours of analysis, laboratory testing, verification in a simulator and two test flights, including an in-flight certification test with Federal Aviation Administration (FAA) representatives on board as observers.
The additional layers of protection include:
- Flight control system will now compare inputs from both AOA sensors. If the sensors disagree by 5.5 degrees or more with the flaps retracted, MCAS will not activate. An indicator on the flight deck display will alert the pilots.
- If MCAS is activated in non-normal conditions, it will only provide one input for each elevated AOA event. There are no known or envisioned failure conditions where MCAS will provide multiple inputs.
- MCAS can never command more stabilizer input than can be counteracted by the flight crew pulling back on the column. The pilots will continue to always have the ability to override MCAS and manually control the airplane. These updates reduce the crew’s workload in non-normal flight situations and prevent erroneous data from causing MCAS activation.
We continue to work with the FAA and other regulatory agencies on the certification of the software update.
Source: https://www.boeing.com/commercial/737max/737-max-software-updates.page
