Peter wrote:
But certified planes are legal by virtue of having a CofA and a current Release to Service, which throws the burden of proof of unairworthiness back onto the challenger, and that is always going to be a steeper hill to climb. Consequently insurance usually pays out, whereas in every case it could avoid doing so if they so wished, and looked hard enough
If I understand you correctly, all of the above would also be true for an FAA registered EAB aircraft, and the insurance issue is basically the same. The only difference is the ‘standards’ are different. Insurance is in any case available.
One side note is on the definition of ‘current release to service’ for any aircraft. If the plane has a current annual or condition inspection logbook entry, its legal unless it doesn’t conform to the approved design. Whatever maintenance has been done since then can have a substantial potential effect on airworthiness, but a (non-IA) A&P Mechanic or Repairman does not legally release an aircraft to service, correct? I’ve never understood in the real world how ‘release to service’ has much role to play for FAA registered aircraft operating under Part 91.
Peter wrote:
But strictly speaking using one washer under a screw without the washer being traceable and written up in the work pack, renders the aircraft unairworthy because the work was incorrectly documented.
That may be true for an airliner, but neither ‘work pack’ or parts traceability are required for FAA certified aircraft operating under Part 91. What’s required is a maintenance logbook entry in which the mechanic signs for work done and that the parts used conform with the TC requirement.
Part 91 etc support reasonable operation of private certified aircraft.
Rwy20 wrote:
Do you have anything to substantiate that claim that builders have a different attitude to risk than non-builders, and that they are more prone to having accidents? Or is this pure conjecture?
I didn’t say that, rather the opposite. In the US, where 95% of homebuilds are, the FAA and the NTSB have investigated this in great detail. Here is the report.
This is the main findings:
The study compared the accident experience of E-AB aircraft with that of similar
non-E-AB general aviation aircraft over the last decade. A detailed analysis was also conducted
of the 224 accidents, involving 227 E-AB aircraft, that occurred during 2011.1
These analyses revealed the following factors defining E-AB aircraft accidents:
E-AB aircraft account for a disproportionate number of total accidents and an even
more disproportionate share of fatal accidents when compared with similar non-E-AB
aircraft conducting similar flight operations.
Accident analyses indicate that powerplant failures and loss of control in flight are the
most common E-AB aircraft accident occurrences by a large margin and that accident
occurrences are similar for both new and used aircraf.
Structural failures have not been a common occurrence among E-AB aircraft.
In comparison with similar non-E-AB aircraft, a much higher proportion of accidents
involving E-AB aircraft occur early in the operational life of the aircraft
A similarly large proportion of E-AB aircraft accidents occur shortly after being
purchased by a subsequent owner. For example, 14 of the 224 study accidents
during 2011 occurred during the first flight by a new owner of a used E-AB aircraft.
Through further analysis of the accident record and the results of an EAA survey of
E-AB aircraft owners and builders, the study also found:
The majority of E-AB aircraft are now built from commercial kits, rather than from
purchased plans or original designs.
Pilots of E-AB aircraft, whether involved in accidents or not, have similar, or higher,
levels of total aviation experience than pilots of non-E-AB aircraft engaged in similar
general aviation operations.
Pilots of E-AB accident aircraft, on average, had significantly less flight experience in
the type of aircraft they were flying than pilots of non-E-AB aircraft.
And further, one can read:
Purchasers of used E-AB aircraft face particular challenges in transitioning to the new
aircraft, which are aggravated by the absence, in many cases, of the sort of comprehensive
aircraft flight manual that would be available to the owner of a non-E-AB aircraft. The study
found that, because there is no review of flight test results, not all builders create an aircraft
flight manual or performance documentation for their aircraft. Absent that documentation, the
purchaser of a used E-AB aircraft is not provided with sufficient information to understand the
aircraft‘s controllability throughout all maneuvers, to detect any hazardous operating
characteristics, or to understand emergency procedures
The main point here is that non certified aircraft are not inherently unsafe. But, they are not certified aircraft, and should not be treated as such. This goes for handling, performance and technical aspects. A builder is more likely to realize this, as can be read further down:
During 2011, more E-AB aircraft accidents occurred during the first flight by a new
owner of a used E-AB aircraft than during the first flight of a newly-built aircraft.
This is a very substantial find. You have to remember here that a used E-AB aircraft is a perfectly good flying machine.
LeSving wrote:
In the US, where 95% of homebuilds are, the FAA and the NTSB have investigated this in great detail.
Well, as a US taxpayer, I have to say I find their activity tiresome. They best thing I can see about it is that it’s had no regulatory effect at the grass roots level. Maybe from the FAA perspective the studies are intended to defend US aviation against law maker action, in which I guess you could view it as a necessary evil. Other than that does anybody involved actually care? Will anybody want to change their behavior based on anything they might publish? In general, I don’t think so.
LeSving wrote:
The main point here is that non certified aircraft are not inherently unsafe. But, they are not certified aircraft, and should not be treated as such.
Oddly enough, that’s why they have EXPERIMENTAL written in big letters, in full view of the cockpit. 
LeSving wrote:
You have to remember here that a used E-AB aircraft is a perfectly good flying machine.
I certainly wouldn’t make that assumption, nor would I want to live under any system of regulation that would try to guarantee it being the case. Not all individual experiments, conducted for education and recreation, will result in perfectly good flying machines for anybody or everybody. I can’t see why that would be a reasonable objective. In some cases, like the successful RV series, they might be better planes for the average guy than most certified designs, and that’s great because it gets lots of people owning aircraft. Many of those aircraft get sold and sold again, so several people benefit. But from a principled point of view that’s just one aircraft design and one designer, a very blinkered view of a broad and innovative activity.
RobertL18C wrote:
If there is an experimental which can match the SM SF260D then would be interested. OK the rear seat is for a petite passenger, but otherwise 180 KTAS, mil spec, IFR and +6/-3G.
But the runway requirement is considerable, and so you need to base it at an airport with a long hard runway. It’s a compromise, as usual.
Full sutton 14 aug 16
Neil
Darley Moor, Gamston (UK)
I’ve seen an SF260 in Abbeyshrule back in the 80s when it was abou 600 yards long. Ther big Air Corps guys in it doing some sort of training. They were in and out several times that day, no problems.
Don’t forget that the lots of 260s were sold to third world countries to fly off unimproved strips,
But as someone said above, always stories about parts being hard/slow to get.
[quoted text fixed, hopefully right]
Silvaire wrote:
Maybe from the FAA perspective the studies are intended to defend US aviation against law maker action, in which I guess you could view it as a necessary evil.
I think you are quite right with that and I’d be quite happy if our CAA/AAIB’s would take such pains lay such groundwork. And not only for experimentals but generally. There is more than enough hearsay and lawyerspeak going on in politics which have nothing to do with the truth. A bit of documentation proving the points would be helpful there.
Silvaire wrote:
Maybe from the FAA perspective the studies are intended to defend US aviation against law maker action, in which I guess you could view it as a necessary evil
The NTSB did the studies, and with recommendations to the FAA and to the EAA. I think all normal pilots like the aircraft to be “safe”. The study shown that experimental aircraft are indeed safe. There aren’t more accidents due to structural failures in non certified aircraft than in certified aircraft. There are more accidents due to systems failure (engine and fuel related mostly) and due to lack of transition training. Both these two factors can relatively easily be fixed, they are both due to lack of experience/competence by the owner/pilot. The first important step is to be aware that this is the case, this is the status, and to stop speculating and make quasi theoretical nonsense about the “dangers” of experimental (non-certified) aircraft, and the “virtues” of certification. There also exist a European study, initiated by EASA, about microlights that comes to the same conclusion, more or less.
LeSving wrote:
There aren’t more accidents due to structural failures in non certified aircraft than in certified aircraft. There are more accidents due to systems failure (engine and fuel related mostly) and due to lack of transition training. Both these two factors can relatively easily be fixed, they are both due to lack of experience/competence by the owner/pilot.
This is of no surprise whatsoever.
Sure, images of wings falling off and such are what most people conger up when thinking about “experimental” aircraft, but that’s not at all were the problem lies .
It’s the myriad of seemingly very simple systems that need to be made fail safe. It’s all these small items that on the surface appear to be inconsequential, that will bite you .
This reminds me of an engine failure on a Lancair ES. The builder made a very slight deviation from the plans and used a different remote oil filter set-up. After just a few dozen hours, it suffered an in-flight engine failure that resulted in the brans new engine getting trashed and an off airport landing. Luckily, no one was injured. Turns out that the load on the oil line to the remote filter adapter was too much and the oil hose broke away from the adapter with 100% of the engine oil getting pumped overboard in a matter of seconds.
That’s why they call it EXPERIMENTAL 
A Lancair Evo was recently lost due to in-flight engine failure – cause not yet determined but likely fuel contamination.
break – break
It seems that there were only 2 Insurance underwriters that would take on the Evo, but recently one has ceased. Some are speculating that it will soon be next to impossible to insure the Evo.
And so is the reality of Experimental aircraft risk.
