The UK LAA Permit aircraft have an annual inspection, mods must be approved, new builds must be inspected and approved during construction. First flights of homebuilds must have an approved pilot.
Yet moving a factory-built Jodel DR1050 from a CAA C of A to the LAA Permit system 10 years ago has saved us thousands of £ each year.
I think the problem with certified aircraft is that for it to work in a “normal consumer fashion” way you have to:
You can also be filthy rich of course, but that’s beside the point. A normal PPL pilot are none of those things. In addition, if you are not ready to get your hands dirty, you are also not very likely to have enough knowledge to question the jobs done by a certified maintenance organisation. Certification puts the consumer in a huge disadvantage, at least the consumer who treats the plane in the same way he treats a consumer car.
The problem with homebuilt aircraft is you can purchase stuff that will work (according to the producer), but ends up being trash when put to the test in a real aircraft. On the other hand, you can also “safe” it to the max. Get only traceable hardware and materials, use certified avionics and engines, use standard techniques and solutions, if you think that increases the possibilities for not falling down from the sky. Most people end up being somewhere between those extremes. Some like to “safe it”, not because of safety, but mostly because they want an aircraft that is as problem free as possible, and this also increases second hand value. Some like to experiment a bit, not necessarily because “new is better”, but mostly because it’s fun and “because they can”.
Still, consumer vise I don’t see any difference legally. It is the owner’s responsibility to keep the aircraft airworthy, no matter if it’s certified or not. Keeping the aircraft airworthy has nothing to do with consumer rights, it’s a legal requirement by the authorities. It’s just that airworthiness has different practical implications for the average PPL aircraft owner if he owns a certified aircraft or a non certified aircraft.
I don’t disagree but I think the homebuilt scene is a great example of the ambiguity which led me to start this thread.
The whole position there is hugely ambiguous and the customers want it to be thus because it is to their advantage all the way. In the homebuilt scene you want no supervision (except what you choose to help you build it, or to help you keep it running), no accountability, no need for traceability (because traceability costs more money), no airworthiness requirements, no supervision of mods, etc.
Well, until they crash and then they or their estate will be looking to sue somebody up the supply chain 
If you build an RV, you can buy a Lycoming OEM at reduced price from Vans, or buy another engine separately elsewhere. Even if you buy it from Vans, the guaranties are directly with you and Lycoming. This is the normal thing in the boat world also. Evinrude also sell boats, and then you get a “package”, but it’s the other way around, the boat comes with the engine more or less.
I don’t know if certification changes anything here. I wouldn’t think so, not legally from a consumer rights point of view. Certification is not services or goods that someone sells. It’s the owners duty to assure an airplane is correctly certified. It’s the same thing with cars also. It’s the owners duty to get the car checked every other year, and this check has nothing to do with the usual service given by guaranties by the manufacturer of the car.
Yet, that is exactly what a plane is. The installed kit is usually tightly coupled, with not just wiring but also paperwork.
Peter wrote:
It’s obvious that in the consumer sphere could would not be able to do that. Imagine VW selling a car with an engine bought in from say BMW and having a separate contract for it
It’s actually very normal for boats. The engine (outboard) is usually an “extra” with a contract towards the engine manufacturer. Lots of other “extras” are similar, such as sonar, plotters, radars and so on. A car is a special case in this respect, where the engine is engineered into the car in such a way that you cannot really separate one from the other without doing lots of engineering work to get the car operational again.
Interesting input Howard… I think the key factor here is that using a lawyer is going to be expensive, whereas activating one’s consumer rights (if any) should be a lot cheaper and possibly even free if there is some consumer body willing to take up the case. The 1st problem however will be that almost nobody will understand the complexities…
In the meantime I got this from a UK barrister:
The last sentence is the key one which I was getting at.
One example is the old one concerning the Thielert bankrupcy, where (reportedly) Diamond escaped likely bankrupcy by having separate contracts for the engine and the airframe. It’s obvious that in the consumer sphere could would not be able to do that. Imagine VW selling a car with an engine bought in from say BMW and having a separate contract for it 
Or better still, and more currently topical, VW saying the ECU was made by Bosch But in the Diamond case most of the customers in question were companies (FTOs).
I’m not a lawyer, but I spend a lot of time working as an expert accountant in complex legal disputes. Any opinion I give below in relation to the law on matters such as this should be taken with a large pinch of salt.. and checked with a qualified lawyer…
I think that a big part of the problem with GA contracts as regards the law is that the GA market is very small so there have been (i) very few cases brought and (ii) there are very few lawyers who know the law in this area. This is compounded by the fact that many (but certainly not all) of the potential claimants are either cash-strapped pilots who fly for a hobby or are poor flying schools, or are very rich owners who throw money at their planes without thinking too much. So it’s not very “professional B2B” by its nature. Instead, by its nature it’s a bit amateurish – on both sides in fact seeing as many of the suppliers are ma & pa outfits.
In the absence of a strong and upheld legal framework the main thing that poor supply companies seem to risk is some bad comment and loss of reputation by dissatisfied customers, rather than instead worrying about the cost of losing an expensive fight in court for having delivered bad product and/or installed it badly in someone’s plane.
There are one or two very expensive and talented law firms out there that deal with aviation matters including with GA. Given the level of their fees, with partners charging more than £600 per hour, I think I’d probably want to be owning a jet before thinking about using their services in a commercially beneficial manner, even with a good claim – remembering that in court, the “normal basis” of cost recovery for a successful litigant, results in an award of only approximately 70% of their legal fees, leaving 30% as unrecovered.
“About 10 years ago”
However that isn’t the point.
Well, I know people who would argue that if a KMD550 isn’t on the STC then the installation is illegal anyway because the only permitted wires are what the IM shows
Are you saying the TB20 is not included in the AML for the GNS530W (FAA) STC from Garmin?
