Originally Posted by
billybone
Thank you ! I realize that normally TCAS only provides up/down altitude change alerts supposedly at a range/time sufficient to avoid collision. As I understand it- MCAS only works/engages if/when AP is off, flaps up, etc. And that normally, the AOA sensor provides input to AP. But the disconnect/removal of the yoke/stick switch which has been standard for decades such that a pull or push in opposition to stab/trim input under a TCAS maneuver which would normally cut electric power to stabilizer might be a surprise to many. Seems to me if HAL( MCAS) is/was G limited by design - but no longer is - then a conflict between pilot and HAL is probable ??
I'm having a hard time trying to make out what you are asking here, however let me throw out a few things out there that might help clarify.
MCAS only works with A/P off.
AOA provides an input into several different systems. That has not changed. However, I don't believe there is a direct input from the AOA sensor to the autopilot, but rather feeds indirectly through the Air Data Inertial Reference Unit (ADIRU) and the Stall Management Yaw Damper (SMYD).
When you refer to the "removal of the yoke/stick switch," I think you are talking about the control column cutout switches that prevent trimming in the opposite direction that the control column is displaced (that is, stops nose down trim when pulling back, stops nose up trim when pushing forward). This feature
has not been removed and still functions as designed
except that these switches are bypassed for MCAS activation (and only for MCAS activation).
Any maneuvers flown in response to a TCAS alert would be hand flown, but how the plane reacts would really be no different from any other hand flown maneuver.
Keep in mind that the MCAS software has already been changed to prevent the type of erroneous activation that occurred in the accident aircraft. The only time then that one would see MCAS activate during a TCAS event would be if the pilot mishandled the procedure and brought the aircraft close to a stall. In that case, you want MCAS to activate!
Let's please remember that last point. When the 737MAX approaches a stall, we
want the MCAS to activate just like we want a stick pusher to activate on aircraft that are so equipped. We just don't want it to activate when it is not needed.