Originally Posted by
Swiss51
What exactly do you mean with "compliant"? To the standard of the 1960ties of the 2020ties? Maybe the FAA simply wants to get out of the excessive grandfathering of the 737 family. The requirements for wiring have undergone multiple changes in the past decades, and B was able to evade them throughout the whole lifetime of the 737 through the grandfathering and - in the most recent times - the delegated power of certification. Time to make some substantial corrections.
The NG should have been compliant to the rules and the amendment levels negotiated, according to 21.101 the Changed Product Rule, and documented in the certification basis. It’s not just 1960’s vs 2000’s. Many rules have been amended over time since the original 737 certification. Generally, 21.101 requires that for the date of application, the certification basis is updated for all parts of the design that changed from the original. There are many nuances and exceptions, but that’s the gist of it. The new wiring rules may have been part of amendments that were issued after the NG certification, but prior to the application date of the MAX.
In my opinion, 21.101 itself as amended now is a practical mess, and is used with kid gloves with the applicant which find too many exceptions. 21.101 needs to be amended again, and simplified, in part to remove many provisions for exceptions and to shorten the life span of old regulation amendments. This would mean more new models, fewer derivatives, and more use of rules at the current amendment levels. Issuing this amendment would not get you on the Christmas card list of any OEM’s. But they had their chance to be “partners in safety” and opted to maximize share values instead.