Originally Posted by
BDAttitude
Oooh au contraire.
To the collective body of
professional accident investigators, multiple certificate authorities representing dozens of nations, subject matter experts, and other interested parties such as the aerospace-centric media (i.e. Aviation Week and the like) and the massive army of tort lawyers lining up to sue Boeing:
Now as we know, that a fast speed trim runaway that cannot be stopped by counter trimming is considered a hazardous condition.
And now as we now that this Eaton actuator is a fancy modern microprocessor commutated and speed controlled brushless motor.
Could you please have a look if the actuators electronics - which is hardware and software - have been designed to a suitable design assurance level. Which would be
DAL-B? DAL-A?
Uncontrolled dive is just a bit-flip away.
Thank you!
If each NG actuator now contains HAL instead of some simple motor then there is a whole can of worms lurking under the surface of the NG grandfathered certificate. It has not escaped the notice of most of us here that the failure modes of HAL and those of mechanical controls are very different.
Edmund