[salawat]

Again. Systems required for safe operation of a device by a reasonably competent operator are not something you consider an option.

It's cheaper and safer in the long run to just do the right bloody thing, since you get the whole economy of scale windfall.

[k7mqqn]

Define required. Required by whom? Not by the FAA, at least. So they are extra. So operators decide whether they buy them or not. They didn't, and this is the result.

[salawat]

Required by reasonable/responsible engineering principles.

If you add an automated system that has high control authority, which is fed data by a failure prone sensor, you add redundant information sources, compare/average out inputs and alert the operator to the possible technical issue.

This is a well known engineering pattern. No one tells you to do it. You're expected to be able to identify when something is high risk and act accordingly. If you seriously believe that regulations change designs rather than codifying lessons learned the hard way, I don't know what to tell you, as apparently we start from two completely different sets of axioms when it comes to implementing things others depend on.

The FAA are there to maintain a collection of lessons paid for in blood, and to provide a general process to follow which strikes a balance between manufacturers doing their thing, and the public's interest in not crashing with no survivors, and maintain a cohesive set of guidelines that govern the industry. An FAA inspector can't be looked at as outsourceable common sense for manufacturers and designers however. Due diligence starts at home.

It is up to the people signing off and the engineers overseeing everything to ensure that design is safe, and all outcomes are such that the public interest is best served. Executives and sales be damned.

Unethical engineering costs innocent lives. Dollars are (or should be) secondary in all regards.

The fact this is even debatable demonstrates how much safety ethos has taken a back seat to economic factors in the modern aviation industry.

[free652]

A lot of modern can have collision prediction systems, pretty sure that a lot of them are optional on cheaper trims.

I would say that those are key safety features.