Rather, it brings into question whether the part is in a fit and safe state for flight.
That's the key, and has been a main factor for as long as I can remember. A more important thing to consider is
who is authorized to make this determination, if there is doubt. Pilots should probably not make a determination that an airplane is fit and safe for flight beyond their privileges for elementary maintenance as listed in AWM571. If the question is beyond that, and AME/AMO will have to make the determination.
It is correct that for some types, the maintenance manual and parts manual are not included in the definition of the type design. A person who wished to challenge their applicability should first consider AWM571.02:
Persons who perform maintenance or elementary work are required to follow the manufacturer’s recommendations, or equivalent practices.......... Where the manufacturer has not made specific recommendations, standard industry practices are to be used.
So if you wanted to
not follow the manufacturer's manuals for that aircraft, you'd have to be able to show that there was a
more applicable document for the maintenance you're considering. But check the type certificate data sheet for the aircraft, as some do specifically list the applicable manuals - if they do, you must use those manuals.
We do not see it as accidental that the CARs have been drafted so as to give a narrow ambit to the issue of “conformity to type design.” Otherwise, if the Minister’s interpretation were correct, then every crack or bulge in a hinge or fairing, every popped rivet, every dent, bend or erosion of a part, every chip in paint, every crazing of a window, any amount of leaking fluid, or any of a host of routine defects that are not expressly addressed in a particular maintenance manual, would become an insurmountable obstacle to an AME. The AME could certify the aircraft as being fit and safe, but this would be insufficient
In considering the foregoing the forgoing partial list of defects, I can think of the differences between Cessna and Piper for some of their popular models. Cessna provides many comprehensive examples of negligible damage, so the AME/AMO can sign the plane out as conforming to it's type design while having that defect. I have seen examples of Piper models (PA-28-161) for example, which do not provide any definition for negligible damage, so in theory,
any defect grounds the plane.
AME's seem agreeable to applying reason in the case of such defects generally, but if you're importing the plane, the bar will probably be higher. An example would be hail damage. To a degree, Cessna allows it as being negligible, the PA-28-161 does not. Interestingly, Piper
does allow a defined amount of hail damage for a few very specific types (I have my own opinions as to why only those types). I once had to issue an approval to allow a PA28-161 to have some hail damage, in accordance with Piper data for a different model, so the plane could be imported, otherwise, the airframe would have been scrap upon importation to Canada (it had already been deregistered from the US).
In fairness, an aircraft manufacturer could not possibly imagine all of the damage that their product could sustain, and perhaps be airworthy. And, we the taxpayers, don't want TC spending large amounts of time pre thinking this either, some things are case by case...
.
