Originally Posted by
climber314
The Engine Failure NNC does not specifically state to avoid high AoA or Steep Turns... ?
Flaps stopped MCAS inputs. The accident crew failed to notice that as well.
CATEGORY: Maintenance, Engineering, Flight Operations, Management, Safety
SERVICE REQUEST ID: 4-4298138108
ACCOUNT: Boeing Correspondence (MOM)
DUE DATE: No Action Required
PRODUCT NAME: Airplane
PRODUCT LINE: 737
PRODUCT: Several
ATA: 0000-57
SUBJECT: Information - Multi-Model Stall Warning and Pitch Augmentation Operation
REFERENCES: /A/ MOM-MOM-18-0655-018
A pitch augmentation system function called “Maneuvering Characteristics Augmentation System” (MCAS) is implemented on the 737-8, -9 (MAX) to enhance pitch characteristics with flaps UP and at elevated angles of attack. The MCAS function commands nose down stabilizer to enhance pitch characteristics during steep turns with elevated load factors in manual, flaps up flight. The system is designed to allow the flight crew to use the column trim switch or stabilizer aisle stand cutout switches to override MCAS input. The function is commanded by the the Flight Control Computer using input data from sensors and other airplane systems.
So the only MCAS flight envelope is steep turns? Following a TCAS climb command would not be a problem without MCAS? A windshear escape maneuver would not be in the envelope either, a rare occurrence anyway in the clean config?
But since steep turns are usually only done in the simulator, I think allowing a non linear pull would be good for your crosscheck. As you roll and pull to the bank and pitch required you might see the pitch force decrease but you're flying attitude and performance instruments and you would just allow the aircraft's pitch input to help you maintain attitude if you don't trim in steep turns. Unless the engines actually add so much pitch up that you would have to push. I doubt that based on the amount of down elevator that MCAS inputs.