The amount of misinformation in this thread is startling. Do we really have so many engineering and maintenance professionals in our industry that don't have a clue? It was nice to see a post from twotter if for no other reason that it shows he's alive and kicking and continuing to add nothing important to discussions.
1. You don't need to be a P. Eng to be a DAR so don't bother to continue to push that distinction. A DAR doesn't necessarily do engineering, (by definition) he/she makes findings of compliance with airworthiness standards. Ultimately, a DAR can issue an serialized STC or submit "approved" data to TCCA and have them issue it. Believe it or not, DARs often do not prepare the engineering that they approve. The vast majority of P. Engs employed in Aerospace in Canada do not have delegated power to approve their designs. Imagine if Bombardier depended on their DARs (they call them DADs) to prepare all of the design and compliance data for the aircraft they design and manufacture. That would be a VERY busy group of individuals. Having said that, its also common for DARs in smaller companies to prepare all the drawings and reports required in the STC process. The point here is that "P. Eng" is not interchangeable with "DAR".
2. An AME (again by definition) really has nothing to do with the STC process or engineering (by the definition by the various chartered engineering groups) and retains the AME moniker in some provinces by way of a grandfather clause. An AME does however (again by definition) bear responsibility to perform "repairs" and "modifications" with the appropriate data. (See 571.06)
3. The three types of data (by definition) are "approved", "specified" and "acceptable" and these terms have very specific meaning so be careful not to take them out of context. If someone says you need "acceptable" data, this has very specific meaning. AC 43.13 is "acceptable" data for any aircraft for mods or repairs that are not "major" but can be used under certain circumstances as "specified" data for major mods or repairs on small aircraft.
4. "Specified" data has the same legal authority as "approved" data for modifications and repairs.
5. An "approved repair" under the RDA process, in the context of CAR 571.06 has very specific meaning so don't say "approved repair" to describe maintenance in accordance with an AMM. It's not the same thing. An approved repair "restores" the aircraft after damage. If you have an unwanted hole in your fuselage, an approved repair scheme would allow you to fix it without "modifying" any of the structural qualities of the air-frame. An approved repair is very similar to an SRM repair and is typically used when an SRM repair isn't available or if the operator wants to use an alternate repair scheme. An RDA can be issued by a DAR.
6. There is no magic absolute in most aspects of aviation so don't ever try to state what an AME or a DAR "can" and "can't do on an individual level. It just doesn't matter. Refer to the CARS and discuss things in terms of what the CARS "authorize" a licensed AME to do or "delegates" a DAR (or an MDM for that matter) to do. I'm sure some AMEs can play the banjo but how is that relevant to any discussion? And stop comparing. AMEs especially really need to get over this weird sense of inferiority to DARs that they seem to constantly defend themselves over. A DAR is not a grown-up AME. A DAR is not necessarily smarter, better looking or better paid. A DAR is not a "super-AME". Both (again by definition) have very different roles with some overlapping knowledge. DARs are bound to certain standards and processes that are prescribed by the regulations so don't give them a hard time because your "common sense" detector can't figure out why it costs so much to drill a hole in a pressure bulkhead or why you need three relays and switch to turn on a light or why you need to make 200 rivet holes to fix one hole. If you knew why, you'd be a DAR. AMEs have specific skill sets, many of which aren't interchangeable with a DAR.
7. Speaking of absolutes, there is no overriding requirement to troubleshoot a snag in accordance with any specific procedure but many aircraft manufacturers provide troubleshooting guides. Larger and/or more complex aircraft have troubleshooting guidance within the AMM or in specific documents (like a FIM) that contain guidance and in some cases mandatory steps in troubleshooting, repairing and testing systems. In some cases, not following the instructions is dangerous and just plain stupid. Especially in modern airlines with CAIMS or on systems that can kill you if you're not careful.
8. Swinging a compass in the air on aircraft that are anything other VFR only is just dumb. Swinging a compass using GPS regardless if you are on the ground or in the air in anything other than single engine non-commercial low performance aircraft is just dumb. Thinking that the compass manufacturer's instructions counts as an approved maintenance practice is....well you get the picture.
9. An EIT is not an apprentice P.Eng or an apprentice DAR. Professional development is not the same as cutting your teeth on-the-job. Comparing an "apprenticeship" to the professional development of an EIT or a P. Eng is apples and oranges. In fact, an EIT can be a DAR. I for one think there should be an apprentice program for EITs similar to how they did it "back in the day" when a prospective P. Eng actually had to make a few things before he was allowed to design them. But I digress....
10. If you want to know "how things are done" for the sake of Frank and Orville, read the CARs and the corresponding guidance material. STC? Check 521. Maintenance? 571. Delegations? 505. Why on earth are you relying on some anonymous doofus on the internets? (Me included) Find out for yourselves from authoritative sources.
http://www.tc.gc.ca/eng/civilaviation/r ... s/menu.htm
http://www.tc.gc.ca/eng/civilaviation/o ... nu-455.htm