Paul Dye’s take on the subject:
A Permanent Solution
Very interesting article.
I like this bit
It also should be noted that there have been a number of reports from homebuilders who had their orders canceled when K&P found out that the filters were going to be used on aircraft. Some manufacturers are funny that way—which is why, when you go to AutoZone to buy a Denso alternator, you must weave the story that it is for your beloved ’98 Suzuki Samurai and not your homebuilt airplane.
Reminded me of this where you have to tell Parker it is for a yacht 
Invoice has arrived from LAS so, with a bit of luck…
Plus VAT.
Arrived:
close-up of filter
Got to send off the STC application.
Got the STC immediately.
Nice line in their email (I requested a copy by mail too)
This will be the only copy of the STC. We don’t send via international mail.
Why does anyone bother to go to this trouble when they don’t charge for the STC?
Why does anyone bother to go to this trouble when they don’t charge for the STC?
To restrict use on another aircraft after resale, at least theoretically, and thereby increase their own revenues over the long term.
They say there is a 6 month time limit for applying for the STC.
So if you passed on that oil filter, the new owner would not be able to get an STC for it. He would have to buy a new one from them. The increase in sales must be negligible because planes are rarely parted out.
But what are the chances of somebody finding out?
I don’t get the point of this way of tying it down. It’s like licensing a bit of software which can be used only with a bit of hardware costing say $500. The hardware forms an effective kind of copy protection.
People like to experiment with aftermarket stuff on their planes, don’t always continue with a given product, and often give or sell it to others after they try it for a while. Not everything that’s installed on a plane stays on the plane forever.
In this case, it’s likely the aircraft owner will install the filter. The only STC issue is passing Annual inspection without a logbook entry that references a 337 being filed. To file the 337 legally you probably need the STC applicable to the aircraft or engine serial number. However I doubt in most cases with most IAs that this STC detail would be an issue for future Annual inspections.
Also, it’s probably the case that many of these are installed on Experimental category aircraft free from any such STC or approval requirement.
Silvaire wrote:
To restrict use on another aircraft after resale, at least theoretically, and thereby increase their own revenues over the long term.
More probably relative to their liability insurance.
Installed. A lot smaller than the standard filter
There is a replacement schedule on the filter element but this is probably optional legally, and should be optional since the stainless steel element can be fully inspected.
Don’t forget to order some spare gaskets before you need them. They are also available from McMaster-Carr, so seem to be a “standard” item.
