Seattle - Boeing plans to install an extra safety indicator in the cockpits of all the 737 MAX jets after severe criticism worldwide due to two fatal crashes in just five months.
According to a source close to the matter, the manufacturer will add a warning light in the cockpit of the new 737 MAXs telling pilots if the angle of attack data from two sensors of the aircraft does not match.
Boeing will also retrofit the system for the current 737 MAXs in service.
The Boeing 737 MAXs have two sensors called "Alpha Vane”. These sensors are installed on both sides, in front of the plane.They look like tiny wings. If one of these sensors detects an AOA out of limits, the MCAS (Maneuvering Characteristics Augmentation System) pushes the nose of the aircraft down to prevent a stall situation.
In the current system, one sensor is enough to trigger the anti-stall system. The Lion Air Flight 610 investigation revealed that one of the sensors was broken and sent faulty data to the Flight Control Computer.
The only way to bypass the MCAS is to cut the power feeding the rotor that trims horizontal stabilizer. But investigations for both accidents suggest that the crew of crashed planes might not be trained for it.