Genghis the Engineer wrote:And yes, the new Part 23 is a complete pig's ear.
Can you expand pls? The two or three manufacturers I've spoken to about it are very positive, as is GAMA (As in General Aviation Manufacturers Association) as you can see here
Part 23, as it has existed for at least a quarter century was a reasonably straightforward set of requirements - and built by several well defined committees and authorities. Issues you had could be addressed with an authority who understood the requirement, and in extremis things could be referred to the drafting committees - as was actually quite necessary when new technologies came along. You could take an aircraft TCDS, check the approval basis, and know exactly what you were dealing with in terms of the safety requirements.
With the latest form of CS.23 (and LSA which uses substantially the same approach) all that is gone. The hard requirements we all understand and for which there is a great deal of (usually) clear interpretative material is carted off into interpretative material, essentially sidelining a half century of built up knowledge on how to ensure a safe aeroplane. There are also vague lists of other standards that *can* be used, many of which (such as the ASTM standards) sit behind paywalls so a quick check on the approval basis of just part of an aeroplane costs me £50 or more (as in fact just happened last week looking at something on an LSA aircraft). The management of those standards has also been moved out of the well understood authority processes, to bodies who will basically give a voice to anybody prepared to pay for a seat at the table. Then EASA, having subcontracted stuff out, start adding their own interpretative material and exceptions to documents they don't actually control themselves.
Some standards: part 25, part 22, Section S, VLA, have not gone down that road. Parts 23 and LSA have, and have become extremely hard to work with -and certainly when you approach an aeroplane as an outsider to the OEM, you are spending a lot of time scouting around trying to work out just what the heck was the basis of approval for the basic aeroplane or system, so that you can just start to understand what the approval basis was of the thing you're trying to modify or design.
I am Spartacus, and so is my co-pilot.