Three Part Report on Small Aircraft Safety

[Boudreaux Bob]

The Study raises questions about causes of up to 45,000 deaths in Small Aircraft Accidents in the USA.


Safety last: Lies and coverups mask roots of small-plane carnage (http://www.delawareonline.com/longform/news/nation/2014/06/12/lies-coverups-mask-roots-small-aircraft-carnage-unfit-for-flight-part-1/10405323/)

[dubbleyew eight]

what you are seeing in the referred document is the downside of a century old safety approach - certification.

parts used in aircraft just can't be used. they have to be approved for use.
that approval requires exhaustive testing.

so while "certification" is supposed to create an environment of robustly designed components, in fact what it does is to lock in place the first approved design of something.
as we see in the less rigorously controlled environment of the ordinary motor car the technology has moved on quite a pace and yet there are none of the problems we face with certified locked in place old designs.

some of the problems are masked by only allowing licenced maintenance.
the licence maintainers get accustomed to working with the crap designs and become quite practised at keeping them serviceable.

I'll give two examples of crap designs that are locked in place.
The marvel schebler carburettor works quite reliably but is totally reliant on the soft gasket material between the case halves to effect a seal.
the cases have 4 bolts holding them. if you use anything but the soft gasket material you find that the case halves distort and the carby leaks.
in reality the case needs 6 bolts to hold so that it doesn't distort.
the design of the carby will never be changed because of the astronomical costs of recertifying it.

a dry vac pump has a frangible part in the drive to prevent engine damage if it seizes. problem is that the frangible part fails well before any deterioration in any other part of the vac pump. this is masked by having them replaced every 500 hours. internally the vac pump has a small nut on a bolt that is prevented from coming off by just 3 centre pop marks in the end of the bolt.
it is an absurd design that would be done differently in a new manufacture.
it will be with us for years because it is "certified."

while litigation provides compensation to the injured parties, in concert with the requirements of "certification" it is substantially preventing progress in the design of new systems.

Certification has existed for a century now and litigation have existed for a lot longer. surely it is time for a different approach that both allows for development and prevents the need for litigation by ushering in more competent designs.

"certification" really is way past its 'use by' date.

[212man]

and yet there are none of the problems we face with certified locked in place old designs.


Oh, sure - we never see multi-million number car recalls for safety concerns!

https://recalls.gm.com/?evar18=GMcom#/

For example.....

[500e]

The report is skewed & somewhat alarmist but I think the thrust is in the correct direction.
As d8 says
so while "certification" is supposed to create an environment of robustly designed components, in fact what it does is to lock in place the first approved design of something.
The cost of change becomes prohibitive, + it allows for excessive pricing

some of the problems are masked by only allowing licensed maintenance,
the license maintainers get accustomed to working with the crap designs and become quite practiced at keeping them serviceable.

There are problems with car recalls but the manufacture picks up the bill.:sad:
I wonder how the statistic per hour driven v no of units correlate to aircraft.

[AnFI]

the free market certainly has improved engine reliability and efficiency for cars, dual ingintion uneccessary for cars for example.

[212man]

dual ingintion uneccessary for cars for example.

Probably something to do with the fact that you can pull over, in a car......

[dubbleyew eight]

Probably something to do with the fact that you can pull over, in a car......

no.
a propeller is most efficient at about 1700rpm.
modern aircraft engines push that a bit to 2500 rpm.
an engine that develops best torque around those rpm needs to have a large diameter cylinder.
getting even combustion across the piston face requires more than one flame front so twin ignition is used.

some motorbikes have 5 spark ignition points.

[Boudreaux Bob]

212Man,

With the success of the British Automobile Industry, perhaps you have a point.

However, One can look elsewhere and see reliability has improved over the Years.

Despite the increased use of a single Serpentine Belt to drive all the components which certainly adds to the risk of problems should the belt break, we rarely hear of that happening.

Perhaps we should consider an updating of the Certification Standards much as the Auto Industry has done despite there being no requirement for them to do so as there is no similar certification standard as in use by the Aviation Industry.

There was a time when American Cars were designed for a life of 24,000 to 36,000 miles before needing major over haul. Now, I routinely run my Pickup Trucks to 300,000 miles without such over haul work before trading the old one in for a new one.

That improvement came as a result of market driven forces and not Government Certification requirements.

[dubbleyew eight]

That improvement came as a result of market driven forces and not Government Certification requirements.

because the stamping tooling wears out eventually there is a need to make new tooling.
if you are going to make new tooling why not make a new exciting sales stimulating car?

which allows the automotive engineers to update their designs.

my father discussed one day my incredible little car. 270,000 km and still delivering new car fuel consumptions.
"when all my cars got to 50,000 miles they were stuffed and required a total rebuild if you wanted to keep them."

I saw photos of a daewoo nubira that needed the head off at 280,000km. the honing marks hadn't even begun to wear off the cylinder walls.

the benefits of an steadily improving technology.

[cockney steve]

Certification adds a ludicrously disproportionate cost to every aircraft...not such a problem , to certify a passenger-jet seat,where tens of thousands are going to be made, but a deal-breaker in something unlikely to hit a production much over a thousand units.....

Why not simply do as LAA approval seems to? Apply "Fitness for purpose" WITH THE DESIGNER CARRYING THE BURDEN OF PROOF
The regulatory inspector need only be held culpable in cases of gross incompetence, dereliction of duty or wilful omission.....
That way, the inadequate float, which should sell for less than £10, could be cheaply and easily withdrawn and replaced. The manufacturer should have mandatory product-liability insurance to include punitive damages cover, in the event of any lying, cheating, falsification and denial where a fault manifests.

It works in the motor industry( though I have reservations about the exploitative misuse of monopoly for computer "brains")
By and large, the motor industry tries to get it right first time....Failure to recall can prove expensive......I cannot understand why, in the cases quoted, the damages were pared down to a fraction of their award. Whilst there is no massive fine, for failure to act in a timely and responsible fashion, they will continue to have an incentive to cover-up known faults.
Perhaps the punitive damages should be awarded to the regulatory authority, thus incentivising them to actively seek out the real cause of accidents and get them addressed.

GA will never be a large market in the UK, whilst certified machines cost an average-man's wage to keep in the air...In that way, Aviation, UK style, is elitist. Those who are allowed the "Permit" route to fly, are penalised by limitation on types and operations....artificial barriers erected to justify the Certified regimen.