AdamFrisch wrote:
This is how most rare types or warbirds are maintained.
Warbirds have never, ever been certified aircraft. Not in the civilian sense, unless they aren’t actually warbirds (owned by the military), but a civilian counterpart. The military is their own “aviation authority” with their own standards and procedures, and can do whatever they want with an aircraft. Thus any “owner or operator produced articles” are matters of contract specifications at most.
A civilian warbird can never become a certified aircraft, because no certifications exists. Therefore there cannot be and “owner or operator produced articles” there either, because that is a definition only valid for certified aircraft.
In Norway, all these aircraft (Annex II, or warbirds, vintage and experimentals mostly) are put in maintenance class III, while normal (ICAO compliant, or C of A in accordance with ICAO) private light aircraft are put in class II. In class III, anyone (in principle) can do maintenance, do smaller and larger repairs, as well as smaller or larger modifications. For a Cub for instance, lots of manufacturers produce airframe parts, and anyone of them can be used without the part having to be an “owner or operator produced article”. In class II, this can also be done, but only for smaller repairs and smaller modifications (in principle). I have no idea how such a “owner or operator produced article” is handled within EASA, maybe they are not, any aircraft requiring such parts are automatically labelled as Annex II?
What I mean is that for two identical aircraft, one FAA registered and one Annex II (EASA), at least for the Annex II aircraft you most certainly can replace, repair and modify as needed, without the article having to be “owner or operator produced”. So, IMO it would be very odd that you should not be allowed to do a tiny repair in some electronics on an FAA aircraft.
A civilian warbird can never become a certified aircraft, because no certifications exists
Plenty on a G-reg CofA, £250k… One owner told me recently there are none left, however.
It was done by taking an ex-mil one (a mere snip at £80k) taking it to bits, printing off an EASA-1 form for every part, and putting it back together.
So, IMO it would be very odd that you should not be allowed to do a tiny repair in some electronics on an FAA aircraft.
If it is a certified one, that’s an interesting debate. I think the main issue is that the owner produced part has to be demonstrably a replacement for the original, and for most electronics you don’t have the design data. This is one good example.
If it wasn’t for this requirement, it would be “trivial” for (in this case) any half competent electronics design engineer to knock up a superior fuel level measurement system. Also you could substantially rebuild all kinds of other bits. You could build your own autopilot – even if the regs required the user interface to be identical. Clearly that cannot be allowed 
I think I found the reference I was looking for in AC20-62E Definitions:
n. Owner/Operator Produced Part. Parts that were produced by an owner/operator for installation on their own aircraft (i.e., by a certificated air carrier). An owner/operator is considered a producer of a part, if the owner participated in controlling the design, manufacture, or quality of the part. Participating in the design of the part can include supervising the manufacture of the part or providing the manufacturer with the following: the design data, the materials with which to make the part, the fabrication processes, assembly methods, or the quality control (QC) procedures.
http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2020-62E.pdf
Peter wrote:
Plenty on a G-reg CofA, £250k… One owner told me recently there are none left, however.It was done by taking an ex-mil one (a mere snip at £80k) taking it to bits, printing off an EASA-1 form for every part, and putting it back together.
OK, but you cannot do that if the aircraft has no civilian certified counterpart. An EASA-1 form is a piece of paper stating the part was indeed produced according to approved (civilian) design data. You wont find many such parts on a Dassault Mirage III for instance. The main issue to start with is what to do when you cannot find parts that are produced according to design data, hence you have to produce it yourself.
Peter wrote:
If it wasn’t for this requirement, it would be “trivial” for (in this case) any half competent electronics design engineer to knock up a superior fuel level measurement system. Also you could substantially rebuild all kinds of other bits. You could build your own autopilot – even if the regs required the user interface to be identical. Clearly that cannot be allowed
Indeed, and this is what experimental regs are for (also, in addition to homebuilt). Besides, I don’t see why you need design data, if all you are going to do is to produce something identical. For a mechanical thing this would mean a material certificate and equal shape and dimensions, or simply replacing standard nuts and bolts and rivets. Surely there must be something similar for individual electronics components?
@LeSving, it was a regular practice for US piston engined warbirds to have an FAA type certificate. That’s one reason many of them were sold for civilian service after their military careers were over. Some do operate in Experimental today because it makes maintenance easier.
Here are the AT-6 and P-51 Mustang type certificate data sheets.
Interesting. At first, homebuilts in Norway were also type certified from what I have heard, one type each aircraft. There were no experimental type.
homebuilts in Norway were also type certified from what I have heard, one type each aircraft. There were no experimental type.
This terminology issue keeps coming up…
Just because something is “certified” doesn’t mean it has an ICAO compliant CofA.
An ICAO compliant CofA means that the aircraft has, under the treaty, the right to fly worldwide provided that the pilot has papers issued by the State of aircraft registry. VFR or IFR as appropriate (unless restricted to VFR on the TC etc), NON commercial. Examples include a Cessna 150, PA28, SR22, TBM850, A330, etc…
A homebuilt with a “certificate” can’t do this because it is not an ICAO compliant CofA. In this respect the “certificate” is no different from say a UK LAA Permit or any other bit of paper under which a homebuilt might be flying under. These aircraft have no international flying rights. Examples include a Spitfire, RV8, Lancair 320, Vulcan bomber, etc.
Could it be that in Norway, homebuilts were once given an ICAO compliant C of A, after extensive flight testing done on a tedious and time consuming individual basis? In the absence of much legal structure, as was more often the case in the past, I could imagine that may have been the case.
In most countries, all aircraft have certificates of airworthiness, the concept of an annually renewed permit to fly is relatively unusual. That’s why the UK tendency to call certified aircraft “C of A Aircraft” is inappropriate. Equally, and for the same reason, “certificated” and “certified” are two different things, as discussed in previous EuroGA threads.
All that said, there are definitely operating limitations associated with both the individual aircraft and type of airworthiness certificate. Homebuilts do not typically have an ICAO compliant C of A. I’m not certain but I believe most US piston engined warbirds having a TC do have an ICAO compliant TC.
Could it be that in Norway, homebuilts were once given an ICAO compliant C of A, after extensive flight testing done on a tedious and time consuming induvidual basis? In the absence of much legal structure, as was more often the case in the past, I could imagine that may have been the case.
It would take, ahem, quite a lot of testing… You would be creating a certified aircraft.
The other approach is to do some (what would have to be a) slimmed-down development and testing programme, issue an ICAO CofA, and file a Difference to ICAO. One could check if Norway ever did this; there is some Appendix somewhere which lists all differences filed. But I don’t believe it. ICAO member states would have the right to object to overflight and this shortcut to certification would create a huge opportunity and thus an uproar.
Both Norway and Switzerland are “rich” countries, with plenty of “rich” pilots who know how this game works, and we would have heard about it by now.
I’m not certain but I believe most US piston engined warbirds having a TC do have an ICAO compliant TC.
That’s possible but only because the USA owns the known aviation universe and has done a lot of stuff without filing a Difference (starting, I believe, with auto Class C/D clearance upon 2-way radio contact)
I went to a presentation by an FAA lawyer some years ago who just shrugged her shoulders and said What’s been done is done and nobody is going to do anything about it now.
Peter wrote:
It would take, ahem, quite a lot of testing… You would be creating a certified aircraft.
Since we’re talking about the past, and as a point of reference, some common production types were long ago certified in a couple of weeks. The Luscombe 8 was designed in 1937, first flown in December 1937 and placed on sale in July 1938. Six thousand were then built over 20 years, of which maybe a third are still flying. The entire design, prototype build, certification, production start and first delivery process took something less than 18 months. It wasn’t certified with reference to ICAO, since that organization didn’t exist, but has always had an ICAO compliant TC from the time ICAO was created. The Piper Cub is another good example.
Aircraft certification was different in many ways in the past, and much less problematic even for certified aircraft that can today be flown anywhere. I think it’s within the realm of possibility that homebuilts got standard TCs in some places long ago on an individual basis, because that’s the only kind of TC that existed. Who knows? 
