bocefus said:
Umm yeah, what is misleading, is to state that FAR 25 and CAR 4B are equivalents, because they are not.
Oh? Really? CAR4b was the airworthiness standards for transport category airplanes prior to December 24, 1964, Part 25 is airworthiness standards for transport category airplanes after to December 24, 1964. If you don't think that CAR4b is the pre-1965 equivalent of Part 25 then you may need to review the definition of equivalent. You may notice that "equivalent" doesn’t mean "identical to"
bocefus said:
Ask yourself why 727's were produced and certificated under CAR 4B even when FAR 25 was effective and in place.
Because the 727 was initially certificated prior to 1965 under CAR4b, and 21.101 allows subsequent changes to a type certificate to be made under the airworthiness requirements existing at the time of the original application for type certificate, provided certain conditions are met.
It’s that simple. Do you really not know this stuff?
That being said, some of the changes of the 727-200 and 200f are governed by Part 25 rather than CAR4b.
bocefus said:
Why do civil airworthiness authorities continue to release supplemental inspection/maintenance requirements that are only required to comply with the regulation that was in effect at the time of original certification?
Wow, you really are in need of some remedial instruction in aircraft certification. OK. I’ll use an example: Say there’s a problem with the seat back latch in a C-172Q, which requires a maintenance or inspection procedure under an Airworthiness Directive. If such maintenance or inspection procedures were required to comply with the current airworthiness standards, the only way this could possibly be done would be to remove the seats and replace them with newly manufactured ones of a new design, because there is no way that the older style Cessna seats could ever be modified to meet the crash protection requirements of 23.561 and 23.562, which didn’t exist when the 172Q was certificated.
So the FAA could chose to require any supplemental maintenance procedure to bring an aircraft into compliance with the current airworthiness standards, which would be an impossible burden in many situations, or it could chose to require that supplemental maintenance procedures comply with the airworthiness requirements applicable at the time of certification. Personally, I’m glad that they chose the latter, but in either case it doesn’t support the pointless and incorrect semantic argument you’re trying to make.
