Certified v Uncertified

[Case]

Hi All,

 

Can anyone tell what exactly is the difference between certified and uncertified aircraft engines ?.

 

Do certified engines have different (better quality) parts ?

 

Regards

 

Case

 

 

[Guest micgrace]

Hi,

 

Certified means tested to a design standard eg. 101.55

 

i.e. test run for various times at various loadings to strict

 

standards. Look 101.55 up (not the only standard) but the one most applicable to RAA.

 

Uncertified

 

does not mean substandard parts. All certified engines started as

 

uncertified at some point till testing and other paperwork requirements

 

were passed.

 

Your you beut certified engine rapidly becomes uncertified the second you change a plug or oil (in GA anyway and God help you if you do)

 

for our purposes it was certified, but to be brought back to certified

 

status it's off to the LAME with fistfulls of dollars. IFF they'll do

 

it.

 

It's actually a little more complex than that, I hope that helps somewhat

 

Micgrace

 

 

[Case]

Thanks Michael,

 

That is clear enough.

 

regards

 

Case

 

 

[Guest Fred Bear]

Depending on the engine manufacturer, certified aircraft engines can

 

also be built to more exacting tolerances. Certified also equals

 

expensive. A good example of this is the Rotax 912 and Rotas 912A, with

 

the latter being the certified version and far more expensive. Aside

 

from price and paperwork the engines are 99% the same, however the

 

certified version is more likely to have been checked and re-checked.

 

It's a bit of a catch 22 however, because it's not like an engine might

 

be a little dodgey, so they just call that one a non-certified model,

 

it's more about processes, quality assurance, paperwork and liability.

 

Hope that muddles things for you enough.

 

Clem.

 

 

[Guest micgrace]

The processes are mainly the same if certified or uncertified. Mainly paying for the legal liability (plus testing etc) if certified. If uncertified you get to carry the liability not the company.

 

Due

 

to small production runs a manufacturer is hardly likely to have any

 

changes in production between uncertified/certified. This simply

 

doesn't make economic sense.

 

Micgrace