Does that heat-treatment involve carburizing? Commonly done for case-hardening of lower-carbon steels. I've done that, too. Baking the steel in a bed of charcoal and (sometimes) cyanide drives the carbon into the steel.
No, just a straight heat, quench, and temper. But you can't heat treat thick sections as high because the core won't quench fast enough.
but if you fly with that, you're pretty much begging to fall out of the sky! (/sarcasm)
thank you for the correction on "drawing" vs "schematic" language! I should probably get that right before I show up to a machine shop and have them build this!
I did extensive work on an Maule M4. I like that airplane. As an aircraft mechanic with machining and welding experience, there was almost nothing on that airframe that I couldn't make, or use an industrial substitute. Here in Canada, if I bought that model, I would immediately register it in the Owner-Maintenance category just so I could legally make new parts.
Except you’re A&P cannot approve the part. He can only install it per Part 43. Bottomline, of all the Part 21 part production approval methods the OPP route is the most flexible and least restrictive of all of them. An while you believe it’s a “one-time” event for the OEM its not. Its more of an ongoing process for the OEM or PMA producer as they must continually keep track of all parts produced under their approvals from the raw materials to vendors to the finish part. And all that accountability has a cost. And so on.
Because the OPP authorization is just for your aircraft. Now get 20 other owners involved at the same time and your golden. For example, there was a group of owners who combined forces and OPP’d complete sets of Cessna flap tracks for all their aircraft.
As noted, there is nothing that prevents that. Some have even tried to consolidate things like this guy. OPPs are simply not used much at the Part 91 level mainly because both owners and mechanics do not understand the process. At the 135 and 121 levels OPPs are used on a regular basis for all sorts of parts.
Not at all. You can legally install anything you want on your aircraft provided you learn and understand how those rules actually work. For example, there are two routes to install parts on your TC'd aircraft: either as a Part 21 replacement part or as a Part 43 alteration part. In very general terms, the Part 21 route keeps the type design intact so those parts must conform to the type design, ie., must be approved in some fashion. However, with a Part 43 alteration, the type design is altered so the "approval" moves from the part per se up to the entire alteration. It is how I can legally install an off-the-shelf "non-approved" marine radio into a TC'd 172 or similar.
Interesting. By “type certificate” you mean the parts manual? As to CAR 3, you’ll find most legacy SELs were certified under CAR 3 or even CAR 4a. So they all use the same rules when it comes to parts and what can be installed.
Per the usual, thank you for filling in the considerable gaps in my knowledge on how this stuff works
This is probably the foremost article written on owner produced parts. Using it as a guide, the part you end up with will be equal to a PMA part approval. Perhaps give your mechanic a copy and see what he says since his only part is to install it.
VARMA and Owner Produced Parts
You do need to be careful with a group OPP. A bunch of Mooney guys had to remove their Johnson bar down lock blocks as the FAA determined that the did not meet the OPP criteria.
Its not the first time thats happened. Usually there is one person that makes a part in his basement then convinces his buddies to "buy" one from him for their aircraft. Other than each owner should fully understand how OPPs work, one step I require to keep things in order is for an owner to make a mx records entry that identifies the OPP part and that it was produced under 21.9 per XXX approved data.
Great example of up charging for a simple v belt that’s been available for decades…