Just been reading the US AOPA magazine, and a very interesting article on buying a homebuilt plane.
It has some pretty staggering info e.g.
This is probably 10x worse than certifieds. It reflects stuff I hear around the place, which of course never gets posted.
Reasons for this disastrous situation include
Basically, if you are buying an already built homebuilt, you have to be really careful. In most cases, the builder only ever built that one plane, and quite possibly not even the whole of it. Some projects are built over decades, so depending on when the engine was purchased you could have corrosion inside that too.
Isn’t it more surprising, that 60-70% of the homebuilts being sold are obviously built to a standard that you would literally bet your life on it?
I honestly don’t understand both sides of this market:
As a buyer I would never consider a homebuilt as there are so many things that can have been done wrong which can’t be checked in a prebuy
As a seller I can not imagine selling something where I put thousands of hours in at a price that leads to a really ridiculous hourly rate.
Also consider that 30%-40% of inspections does not represent 30%-40% of aircraft.
Imagine 2 aircraft for sale. One is perfect and one is has a deal killing flaw.
A serious buyer does a prebuy on both. They reject the poor one and buy the good one.
Another buyer comes along and prebuys the poor one and rejects it, waiting for something better to come along.
Another buyer comes along and prebuys the poor one and rejects it, waiting for something better to come along.
That’s 4 prebuys, but only 25% result in an acceptable outcome. But it’s not 25% of the aircraft that were acceptable; 50% of the aircraft were acceptable.
I’m sure poor aircraft wait much longer to get sold and have many more prebuy inspections done than good aircraft.
I suspect a bigger issue is finding someone who is experienced enough on the type to do an inspection, yet isn’t connected to the seller. Many home built aircraft are built in relatively small numbers making it a small community.
LAA Permit Homebuilds are supervised – stages signed-off by an LAA Inspector. Areas not accessible when completed will have been examined during build.(e.g. inside wing spar. The US is different.
An interesting figure would be the % of Certified sales where problems show despite the prebuy. That would be 100% of the two I’m familiar with.
“Many home built aircraft are built in relatively small numbers making it a small community.”
That makes finding someone easier, in a comparatively small country like the UK
I think the UK LAA and its relatively tough regime is pretty unique.
This is reflected in a buyer having the same privileges as a builder.
I don’t know why the AOPA article would be shocking to anybody… in the US these are Experimental aircraft, by intent of the category. Some of them actually do include individual experiments, by design, that a given buyer may decide are not suitable for their intended service. Many individual, experimental design solutions are actually fine, but the buyer and pre-buy inspector may be uncomfortable with having no assurance based on multiple applications and familiarity. The pre-buy inspector is not being hired as an aeronautical engineer. Also, the ‘not changeable at reasonable cost’ issue depends on the buyers capability, so is an over generalization: some people can change things a lot easier and faster than others, particularly when unregulated.
All of that said, there are plenty out there for sale in the US that a buyer looking for a certified aircraft surrogate would find acceptable, because there are plenty of builders that wanted that when they built the plane. Just not all of them. Experimentals are now more common than Certified in the group in which I fly and socialize. There’s something for everybody.
The amount of time, money, knowledge, working space and other resources required to own, update, rework, overhaul, operate and enjoy an FAA Experimental is not intimidating to a great many people, whether as initial builder or subsequent owner. The reason they do it is simple – its educational and fun.
Peter wrote:
I think the UK LAA and its relatively tough regime is pretty unique.
It’s the US regime that is unique. Experimentals there are literally experimental (in the practical sense), or at least they can be, and no QA is needed regardless. In any other place on earth to my knowledge, some QA by another person is needed of the craftsmanship. Minor modifications (in a kit) will require an “approval” by at least one other “knowledgeable” person. Major modifications, or entire new aircraft or kits, needs basic engineering and approval of that engineering.
But, when talking about experimental homebuilts, we mean kit planes (99%), or at least built from drawings. In that sense the LAA is probably unique because they often make changes to kits to make them fit “LAA standards”. From what I have seen, this could be anything from the cockpit layout to specifications of materials and fasteners and changes in structures. A pit pedantic perhaps, but I would also think it’s OK for most people building planes at home.
Considering dubious statistics as mentioned above, and the US regime, I really don’t find it staggering that errors are often found, in the US.
Again, it’s likely not “errors” that are found in a pre-buy inspection of an Experimental Category aircraft, because there is no approved design data to which one can compare a given plane.
The only people who would want a shop to do a pre-buy on a homebuilt are those who are looking to buy something built to the kind of experienced-based, conservative design basis that exists within a mechanics head, one who builds his business by being ‘tough’ and ‘saving people money’. It’s fine for those with that preference and with corresponding resource limits. It’s not however the intent of the FAA Experimental Category, or of most people who design, build and operate at a higher technical level within it – the intent that created most of the home built designs in existence.
The AOPA article reflects views of the ‘kiddie-safe preference’ end of the buyer spectrum, as one might expect of a magazine with a spectacularly wide spectrum of readership.
As the story goes, VanGrunsven have said that they design the aircraft with twice as many rivets as required. If a builder manages only half of them OK, the aircraft is still within “specs” 
True or not, I don’t know, but all good kits are designed with the amateur builder in mind. The aircraft will be structurally sound even if the craftsmanship is at a lower standard than would normally be approved for a factory built aircraft.
Technically this is the same as factory built composite aircraft. Due to unverified fatigue properties, the structure has to be designed with this in mind.
As the story goes, VanGrunsven have said that they design the aircraft with twice as many rivets as required. If a builder manages only half of them OK, the aircraft is still within “specs”
It also means you’re twice as likely to find a bad rivet!
