Originally Posted by
yoko1
Keep in mind that the MCAS software has already been changed to prevent the type of erroneous activation that occurred in the accident aircraft.
CS 25.671
C: The aeroplane must be shown by analysis, test, or both, to be capable of continued safe flight and landing after any of the following failures or jamming in the flight control system and surfaces (including trim, lift, drag, and feel systems) within the normal flight envelope, without requiring exceptional piloting skill or strength.
C3: A runaway of a flight control to an adverse position and jam must be accounted for if such runaway and subsequent jamming is not extremely improbable. (Probability of 1 x 10-9 or less per flying hour )
Electronics with probability of failure less than 1 x 10-9 per flying hour, must be designed according to DAL Level A. In this forum DAL Level C have been mentioned, this is 10000 times less reliable.
I don’t understand why fixing the MCAS algorithm helps, when THS is controlled by a DAL C system that is expected to fail at less than 1 x 10-5 pr. Hour.