Originally Posted by
Bend alot
When you kill that MCAS or it has it's once limited "correction" - you are flying an aircraft that can no longer meet the certification requirements that it is approved for!
So say again - it no longer can meet certification requirements in certain flight modes/areas.
So how often do you fly outside certification limits? and how much training did you receive to do that? and was it on an Ipad?
This is not retaining - you have never flown in un-certifiable condition before on a 737 where MACS is required but not available.
Note this has nothing to do with a MCAS run away or trim run away - this is in normal flight when MCAS has been shut down (a number of events can now do this) or had one input and can not now, put in a second input to keep in certification limits..
I agree with most of your concerns, and have made similar comments myself. The revised MCAS details are still not clear, but there are two "escape" causes that could bypass your argument:
- The first is that MCAS may not be imited to one activation per flight, but can do so again, if a specific set of conditions permit. For example, nose-down trim unwinding, or AOA remaining below the threshold, together with no pilot control inputs for 15 continuous seconds.
- The second is that AOA disagree could be treated as a MEL equipment failure, and mandate landing at the nearest avaliable airport. I have not seen any reference to this, so the implication may be that MCAS is not flight critical, but rather a paper certification issue for a rarely encountered flight condition.
Whether the Joint Authorities Technical Review buy either of these arguments remains to be seen.
Edit: My comment was drafted while other replies to the same point were posted.