Although no official findings have yet to be released, Indonesian aviation authorities are focusing on the aircraft’s automatic system designed to prevent the 737 Max 8 aircraft from entering an aerodynamic stall. The system, not found on predecessor 737 models, is known as the Maneuvering Characteristics Augmentation System or M.C.A.S. The system works in conjunction with Angle of Attack sensors located in the fuselage of the aircraft. These sensors measure the angle of the aircraft in relation to the air that comes across it. If these sensors indicate that the angle of attack or AOA is too high, they will transmit this information to the M.C.A.S. which will cause the forward edge stabilizers located on the aircraft’s tail to push up thereby forcing the nose of the aircraft downward. If the M.C.A.S. did in fact engage as a result of faulty information transmitted by the aircraft’s AOA sensors, the pilots would have been confronted with a situation for which they were not trained and would have required them to rapidly engage in a series of steps to take control of the aircraft away from the M.C.A.S. If they attempted to simply raise the nose of the aircraft by pulling back on the control yoke – which likely would have been the flight crew’s natural reaction – this would have had little effect as the forces exerted by the M.C.A.S. are much greater than the pilot could muster through pulling back on the control yoke. Instead, the pilots would have had to quickly respond with a number of actions for which they had received no training in order to regain control of the aircraft and disable the M.C.A.S.
Numerous airlines and pilot unions have contacted Boeing expressing outrage that the M.C.A.S. was not specifically disclosed to them as a purported enhanced safety feature on the 737 Max 8 aircraft and also, that they received no specific training on how to disable the system should a problem arise.
It is still unknown if a faulty AOA sensor caused the M.C.A.S. to activate ultimately causing Lion Air Flight 610 to enter an uncontrolled descent into the Java Sea killing all passengers and crew. However, if it is ultimately determined that Boeing failed to sufficiently disclose the existence of the system or failed to advise airlines of proper system training, it is likely that additional action will be taken by the Federal Aviation Administration and other governmental aviation authorities to ensure that Boeing disclose all pertinent information to prevent a tragedy like this from ever occurring again. As more information becomes available, we will provide further updates.