Originally Posted by
Snyggapa
I would also be fascinated if a gap analysis has been done between the MAX and what would need to change, were it a new aircraft type being certified today - several people have commented that "it would never be certified today" and "it relies on grandfather certification" - so in what ways does the MAX come up short to today's expected regulations?
Fair questions. The relevant regulations are generally referred to as the "Changed Product Rule", and are documented in 14 CFR part 21.101 and 21.19. FAA Advisory Circular 21.101-18 provides guidance on how to interpret and apply the regulations, including how to perform a gap analysis to compare the previous regulation to the new regulation.
https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_21.101-1B.pdf The general takeaway is the changed systems, and affected systems that are unchanged but impacted by change, must generally step-up and comply with the most recent regulations.
The certification basis of an aircraft is a list of which regulations it has been demonstrated to comply with, and at which amendment level of that particular regulation is being used to show compliance. The certification basis is agreed to by the manufacturer and the FAA at the beginning of the certification process. The manufacturer has 5 years to complete certification of the aircraft, and the manufacturer is not required to comply with regulations that are changed within that 5 year period.
The cert basis is documented in the Type Certificate Data Sheet. Here's the 737 TCDS, the MAX 8 is on page 71.
http://www.airweb.faa.gov/Regulatory...6WE_Rev_64.pdf
For each regulation, the center column lists the amendment level that the airplane complies with. NA indicates "No Amendment."
Then, you can go to the CFR and compare the most current amendment level to the amendment level in the TCDS.
https://www.govinfo.gov/content/pkg/...tle14-vol1.pdf
For example, the MAX complies with 25.107 amendment 135 for Takeoff Speed, and that is the current amendment level in the CFR.
Another example, go in the TCDS and look at 25.807 for emergency exits. For some of the doors, the MAX complies with the most current amendment level 114. For others, it complies with amt. 72. Additionally, they are compliant with 25.807(c)(3) at amt. 15, because this section was removed from newer versions of the regulation.