I appreciate the response but it does not help at all one bit, it's a rehash of everything I've already read. In all of these 737 MAX discussions I'm one of the first to have brought up FAR 25.173(c) (although that whole section is relevant).
I do not see how software augmentation can be permitted to compensate for a deviation from FAR 26.173. That section is titled: Static longitudinal stability. Software augmentation cannot cause an airplane that lacks positive static stability to have positive static stability.
You have to understand that what you're proposing represents such a magnificent perversion of FARs, if true, that it is not conceivable to me that this is not a big f'n deal in the aviation community. It would be the elephant in the room, that somehow Boeing and the FAA permitted an airplane that in fact does not have certifiable positive static stability in one or more axis, to have been certified because of a software routine; let alone a software routine with no redundancy and is easily disabled in flight with no documentation on the consequences.
Let me put another fine point on it: I do not care if there are 50 AoA sensors and 100 independent computers on this airplane to compensate for a FAR 25.173 deficiency (or pick any of the other axis for that matter). You cannot use a goddamn computer to make an airplane statically stable when aerodynamically it is not statically stable. At least not without changing the FARs. As they are written, transport category airplanes must comply with FAR 25, and I see nothing in FAR 25 that permits computers papering over aerodynamic requirements.
>I do not see how software augmentation can be permitted to compensate for a deviation from FAR 26.173. That section is titled: Static longitudinal stability. Software augmentation cannot cause an airplane that lacks positive static stability to have positive static stability.
I absolutely 100% agree. At no point have I intended to imply that any software solution should justify exceptional certification of an unairworthy frame as airworthy; in case that isn't clear.
I've only tried to communicate the fact that the software can physically remedy the behavior enough to apparently bring it within the capability of a human to control (as has been demonstrated by the non-crashed flights, as Boeing will inevitably argue).
I absolutely, unequivocally reject any argument that the software fix is compliant with regulations as written, or should be accepted as an acceptable remedy in it's current form.
I've had my view somewhat shaped by D.P. Davies in regard to the application of "gadgets" for certification. I think that any such system must be essentially bulletproof, and avoided at all costs by engineering the problem out if possible; and if allowed must unquestionably get the point across to the pilot that they are in dangerous waters.
The 727 had it's Stick Pusher in the U.K. This seems to be a modern retreating of the same path, and to be honest, I'm siding more toward the conservative side you hold of not allowing MCAS to remedy these handling faults. It really would be an example of the slippery slope of normalization of deviance in action.
I really hope all pilots, aerodynamicsts, and engineers take notice, and speak up. I can sit in these threads and try to spread understanding to the nine winds; but I'm some dude on the Net, who has no professional affiliation to any of this, but a big fat keg of outrage because this is not Quality damnit.
I do not see how software augmentation can be permitted to compensate for a deviation from FAR 26.173. That section is titled: Static longitudinal stability. Software augmentation cannot cause an airplane that lacks positive static stability to have positive static stability.
You have to understand that what you're proposing represents such a magnificent perversion of FARs, if true, that it is not conceivable to me that this is not a big f'n deal in the aviation community. It would be the elephant in the room, that somehow Boeing and the FAA permitted an airplane that in fact does not have certifiable positive static stability in one or more axis, to have been certified because of a software routine; let alone a software routine with no redundancy and is easily disabled in flight with no documentation on the consequences.
Let me put another fine point on it: I do not care if there are 50 AoA sensors and 100 independent computers on this airplane to compensate for a FAR 25.173 deficiency (or pick any of the other axis for that matter). You cannot use a goddamn computer to make an airplane statically stable when aerodynamically it is not statically stable. At least not without changing the FARs. As they are written, transport category airplanes must comply with FAR 25, and I see nothing in FAR 25 that permits computers papering over aerodynamic requirements.