I am pretty sure he was not debating the type or grade as regards the strength or other properties.
It is just an example of something that can be made within the rules but may not necessarily be so easy as some may assume.
Again I get involved a lot in local manufacture of aircraft items. I hear owners talk a lot about 'structural' also but the engineers hardly ever class items as structural or non-structural.
Fairings and other fibreglass items would presumably be classed as non-structural by these same owners. I know I have actually heard owners talking about such fairings as though they were open slather as they were 'non-structural'.
You would have to imagine these fellows actually believe the rules differentiate.... as far as I am aware, they don't !
For major repairs we may hear the terms Primary Structure, Tertiary Structure and the likes.
Yes, we can make new fairings and windows. There are procedures for it. There are also many easier methods that can be used though. One clue would be that it is much easier for a LAME to 'repair' something rather than 'manufacture' it.
Fairings would be a good example there. They can be repaired but to replace may even mean purchasing a STC'd item. We see this with wing tips and wheel fairings.
The rules for local manufacture or 'owner made' are pretty standard about the world.
An owner can make any part. Anything at all and how he/she wants it.
There is nothing stopping them.
What they can't do however is fit it to an airworthy certified aircraft.
They can if the aircraft has the item written up as a defect and the new item is not included in the repair. ie, the aircraft is not released back to service.
You can make a cardboard window, no problems at all.
Many would call that a template though, something you may be using to enable the manufacture of an acrylic one.
Indeed the rules often call for a collaborative effort between the owner and LAME to make parts.
The LAME can't put homemade stuff on your aircraft without your authority. Similarly the owner can't make up stuff and then try and fit it to the plane.
What generally happens is that the LAME tells the owner they need to make a part. The owner must be involved and approves the material specs and other data they require in order to make the part. In the case of a window plastic both parties agree on the thickness, the tint and the material.
The rules make mention of the requirements here. It can not be sub-standard in any way.
The item is then made. Anyone can do that but the owner must have an involvement. Whatever is going on must not be a surprise to the owner.
The only person that can accept and certify the final product and then go on to fit it though is the LAME. The owner has no authority whatsoever there, in any country that I have worked in.
It is a very common procedure all the same and is one we would have to use from time to time. Repairing something is regarded as the easier option all the same. Often it depends on what the LAME is comfortable certifying and how he wants to approach things. AC 43.13-1B is his best friend normally.
An owner is welcome to say it is non structural, won't do any harm and I can knock one up and fit it.
I am sure many guys have that attitude.
There will be many about that say that they own their aircraft and medicals and flight review make no difference. They can fly whenever.
Neither are legal but of course don't stop some pilots flying.
There will be some pilots that want to fly and operate within the rules though.
I would like to think that would be the majority but sometimes you do have to wonder.