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 has been put through hundreds of hours of analysis, laboratory testing, verification in a simulator and numerous test flights. Before it is finalized, the software will be validated during in-flight certification tests with Federal Aviation Administration (FAA) representatives.
The additional layers of protection that are being proposed include:
These updates are expected to 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.
To earn a Boeing 737 type rating certificate, pilots must complete 21 or more days of instructor-led academics and simulator training. To be certified to fly a 737 MAX, a pilots must either complete a 737 MAX specific type-rating course or, if a pilot is already certified to fly the 737NG, they must complete the NG to MAX Differences training.
In preparing for a safe return to service of the MAX, Boeing has proposed a comprehensive training package with new training requirements that will be evaluated and validated by regulators before the aircraft returns to service. After evaluating Boeing’s training proposal, regulators will make the final determination on what the training requirements will be.
Boeing’s training proposal includes a new suite of computer-based training modules, new and updated documentation, and simulator training. These instructional materials are designed to provide 737-type rated pilots with an improved understanding of 737 MAX flight control systems, reinforce their technical knowledge of associated flight deck effects and operational procedures, and restore confidence in the 737 MAX.
We continue to work with regulators as they review the proposed training, and with our customers to understand their training needs and how we can continue to support them as we work to safely return the 737 MAX to service.
All primary flight information required to safely and efficiently operate the 737 MAX is included on the baseline primary flight display. This is true of all our commercial products. Boeing doesn’t put a price on required safety features. Crew procedures and training for safe and efficient operation of the airplane are focused around airplane roll and pitch attitude, altitude, heading and vertical speed, all of which are integrated on the primary flight display. All 737 MAX airplanes display this data in a way that is consistent with pilot training and the fundamental instrument scan pattern that pilots are trained to use.
The AOA (angle of attack) indicator provides supplementary information to the flight crew. The AOA disagree alert provides additional context for understanding the possible cause of air speed and altitude differences between the pilot’s and first officer’s displays. Information for these features is provided by the AOA sensors.
There are no pilot actions or procedures during flight which require knowledge of angle of attack.
Maneuvering Characteristics Augmentation System (MCAS) – flight control law implemented on the 737 MAX to improve aircraft handling characteristics and decrease pitch-up tendency at elevated angles of attack.
Angle of Attack (AOA) – the difference between the pitch angle (nose direction) of the airplane and the angle of the oncoming wind.
Angle of Attack Sensor / Vane – hardware on the outside of the airplane that measures and provides angle of attack information to onboard computers; also referred to as an AOA vane.
Angle of Attack Disagree – a software-based information feature that alerts flight crews when data from left and right angle of attack sensors disagree. This can provide pilots insight into air data disagreements and prompts a maintenance logbook entry.
Angle of Attack Indicator – a software-based information feature that provides angle of attack data to the flight crew through the primary flight displays. It is an option that can be selected by customers.
Control law – a set of software that performs flight control function or task
FCOM (Flight Crew Operations Manual Bulletin) – supplementary operations information
FOTB (Flight Operations Technical Bulletin) – supplementary technical information
Speed trim system – a system that uses multiple components to provide additional speed or pitch stability when needed