Following some discussions with another aircraft owner who has just had a pile of original parts fitted at what looks like a massive premium, can anyone dig up a reference for this?
I am interested in references for both FAA and EASA.
I am pretty sure that under FAA it is not required, except for parts where the Type Certificate calls for specific part numbers – for example a Lycoming IO540-C4D5D engine is going to be awfully hard to replace 
Otherwise, even where a specific P/N is called out, you should still have the PMA route – a PMA part is by definition same as the original part. Are there any exceptions to this?
If there are no relevant exceptions, then it is sure that a large number of people out there, including every N-reg Socata TB owner, are getting completely fleeced by being told that only Socata parts may be used. Even on the US-based Socata owners’ group people are being told this.
Again AIUI the basic requirement under the FARs is that the part must conform to the TCDS or STC. Obviously the OEM part and the PMA part meet this requirement. For Part91 operations the owner or operator can actually manufacture their own parts….provided they meet the TC or STC design specifications… Of course a PMA manufacturer cannot infringe any patent….which may be the Socata argument
Of course a PMA manufacturer cannot infringe any patent….which may be the Socata argument
OK but that is an issue for whoever claims to be the copyright holder, not the aircraft owner.
There is, I understand, a fine line with PMA parts because how do you demonstrate yours is the same as the original, given that the original design is automatically copyright and you can’t get the original drawings. However the PMA system has been robustly working for decades.
Obviously the original part makers, and the airframe makers who try to make money out of selling original parts, all hate the PMA scene, but again that is not an issue for the aircraft owner.
Very few aircraft parts are patented or, if they are, the patents will be mostly bogus (obvious, prior art) and thus not likely to be enforced, or long lapsed. The vast majority of airframe parts in common use have been unchanged for 30+ years so any patents will be expired.
I heard that EASA was going to ban PMA parts, but that was a few years ago. It would be a grossly anticompetitive move.
There is case law that prevents copyright being used to stop others making “spare parts”.
The House of Lords held in British Leyland v Armstrong that the independent manufacture of spare car exhaust pipes was lawful under the Copyright Act 1956 on the basis of an implied right of a vehicle owner to repair it, and non-derogation from grant (1986 AC 577). In other words, the manufacturer, having sold the car, could not then take away from the owner the right to use it by depriving him of replacement parts.
However, more recently Dyson Limited v Qualtex (UK) Limited 2006 EWCA Civ 166. refined the situation and gave more protection to OEMs.
It seems replacement parts which must have certain features to fit on the original device but otherwise have an independent design may still be OK, but will infringe if they are just copies of the OEM’s part, for example if they look the same
[edited to fix up formatting]
I am pretty sure that under FAA it is not required, except for parts where the Type Certificate calls for specific part numbers
If the FAA Type Certificate and by extension the airframe manufacturer’s maintenance manual (MM) lists a supplier (third party) part number, then under FAA rules its legal to obtain the part directly from the third party supplier, or from a fourth party supplier with a PMA to manufacture the part. The latter case is very typical for a part originally manufactured by a small, long defunct supplier – somebody else gets a PMA to make the part and supplies it to owners of all aircraft types using the part. If on the other hand the MM lists an airframe manufacturer specific part number, the part is supposed to be purchased from the airframe manufacturer unless there is a PMA referencing the airframe manufacturer’s part number.
FAA has no legal role in enforcement of patent law, so that is not an airworthiness issue and is therefore not a concern to either FAA or aircraft owner.
Generic parts like a compass or mechanical tachometer are often exchanged for non-original non-PMA TSO’d parts but this can get complicated, and the legal details are outside of my interest 
If my head starts to smoke in trying to decipher the legalities, I talk with a friend who is in the parts manufacturing business. My IA doesn’t much care, so it rapidly becomes an academic point anyway.
Owner manufactured parts officially need to have a 337 filed that provides satisfactory backup for the part being equivalent to the original part. For example I have a crack in a otherwise unobtainable wheel fairing mount that is a simple flat piece of aluminum sheet. Officially, to install a replacement that I can easily make, I’ll need to obtain evidence of the original aluminum alloy (i.e. 2024-T3)
Parts like alternators and exhaust systems are available as ‘rebuilt’ or ‘repaired’ to circumnavigate the PMA issue but are essentially new.
Even on the US-based Socata owners’ group people are being told this.
The solution is to find a new IA – because the only time it matters is during annual inspection, and the IA is the only guy who needs to approve an annual inspection. Manufacturers try to insert themselves through their field tech reps etc, but they have no official role or authority. Obviously a great many normal category aircraft on the FAA register could not be maintained with parts bought from the airframe manufacturer or TC holder, because they haven’t existed for decades. I suspect one reason that situation exists, and will continue to do so, is that it allows FAA to demonstrate to TC holders and airframe manufacturers their proper place in the world.
OK but that is an issue for whoever claims to be the copyright holder, not the aircraft owner.
I mentioned it because I took it from your OP that you meant that Socata were against the use of non-OEM parts….not the regulator
Socata don’t have any overt presence on the Socata owners’ group. The views(s) about using Socata parts come from some people on there.
Here are some resources to look at: http://www.eaavideo.org/video.aspx?v=1105297993001
Google and download these FAA AC’s: AC 20-62E and AC 43-18 Chg 2. The first deals with parts, the second deals with maintenance produced parts.
I had a look through those (not done the video yet) but have not found anything which says if/when any parts must be supplied by the airframe manufacturer.
I guess there are going to be cases when the only part that’s available and which is either TSOd or PMAd happens to be offered by the airframe manufacturer (example: a wing) but that is just a “fait accompli” answer
Components supplied by the airframe manufacturer of an FAA-certified aircraft do not necessarily have to be TSO’d or PMA’d, and are sometimes sourced by them from unexpected subcontract suppliers: a tractor-sourced gascolator and a car windscreen wiper motor driving flaps come to mind. In these cases, I think the official “fait accompli” answer for the owner is indeed to buy it from the airframe manufacturer by their part number, or buy used, or overhaul using approved parts and methods.
The grey area would be when a part comes along from parts unknown, an FAA A&P inspects it and finds it airworthy and totally compliant with the TC, but unbeknownst to him the part has never been anywhere near the aircraft parts ‘system’. The A&P does not need an 8130 so that is a very possible scenario. I expect the FAA likes things just as they are, because in reality it has not caused accidents and the mechanic is responsible for determining airworthiness.
Re wings – people do build replacement wings and other major airframe components for FAA certified aircraft, in particular when all the engineering data is available and the tooling required is not too complicated. A good example might be the Boeing Stearman biplane (as shown on Peter’s website). All the Stearman drawings are US public property and they were done to a very high standard. I understand the Stearman is actually still ‘supported’ by Boeing in some fashion, but some other still-certified types have been field manufactured from an original data plate up long after the original airframe manufacturer was defunct, using original drawings.
