Snoopy wrote:
How does it work in practice?
The owner can „certify“ the part for installation without form 1, and then who installs it and issues the approval?
Installation is as always – an approved shop installs the part. The part approval is issued by the owner.
The other year we replaced a broken KMA26 audio panel with a used one without an EASA Form 1. We supplied the part to our avionics shop. They installed it and had us sign a form where we approved the part in accordance with 21.A.307. That signed form is now with the aircraft documentation instead of a Form 1.
Thanks @airborne
There you go
Is this provision only for replacing broken stuff, or also for adding things?
Concrete example, fitting an HSI and getting rid of a DG:
1. Not life-limited, nor part of the primary structure, nor part of the flight controls.
Check
2. Manufactured in conformity with the applicable design
The HSI pictured below seems legit
3. Marked in accordance with Subpart Q
As for any other part or appliances it needs to be identified (“marked”) for traceability purposes.
So, put a sticker with a number on it?
4. Identified for installation in the specific aircraft.
Fulfilled by the owner signing the form (see the screenshot in the post above.)
Can this HSI be added to say a PA28, instead of a DG?
Snoopy wrote:
Is this provision only for replacing broken stuff, or also for adding things?
Also for adding things. But the provision is only for the parts, not for the modification of the aircraft. You still need a mod approval, CS-STAN, STC or whatever.
So in your case with the KMA26, what was the mod approval? I’d assume since it is an audio panel it was C-STAN?
What can be the path to mod approval for the above pictured HSI?
I could try to find an STC and buy it?
I could ask a DOA to approve the mod?
Anything else?
As an aside, the KCS55 slaved compass system pitcured above would involve quite a lot of wiring. This is the general idea, and I have the proper (readable, unlike what Socata sent to ATP for CD publication) diagrams if needed
Certification-wise, the KCS55 was certified on the TC of many/most “IFR” planes, which would be helpful. You would just need a good wireman 
Afterwards you would be able to keep it running pretty cheap, because lots of people are chucking this stuff out. Previous threads e.g. here and various contrary views e.g. here.
A DOA job is likely to be 4 digits, based on quotes I got in the distant past. It’s a similar process to a US DER.
Snoopy wrote:
So in your case with the KMA26, what was the mod approval? I’d assume since it is an audio panel it was C-STAN?
None, as it was a replacement for an identical unit that had failed.
What can be the path to mod approval for the above pictured HSI?
I would guess Standard Change CS-SC401c.
Thanks! I’m getting close to understanding it.
Airborne_Again wrote:
None, as it was a replacement for an identical unit that had failed.
There was NO mod approval required or the mod was approved using C-STAN?
Snoopy wrote:
There was NO mod approval required or the mod was approved using C-STAN?
There was NO mod approval needed because there was no modification. A failed, factory-installed KMA26 was replaced by a serviceable used KMA26.
Oh my, of course, makes sense.
Thanks so much!
Does it pertain to the individual airplane or the type?
If a DAH AFM offered and lists e.g. a KMA26 as available equipment (in the equipment list) and hence this equipment was approved for the type overall, but an individual aircraft doesn’t have a KMA26 (e.g. anymore), can one be installed without it being a modification?
Besides STC, CS-STAN, a DOA and not needing mod approval due to equipment being exchanged, are there any other approval paths?
