Going past 2000 hour TBO - what to look for

Hello Franco

The original question asks what is needed to extend the recommended TBO of a Rotax.  The FAA has the best guidance in the AC 120-113 on extending time.  Rotax has no such recommendations.  

The answer for different regions will be different depending on how your aircraft was approved in your region or country.  In your case, Italy, then EASA rules would have to be followed.  This again depends on the aircraft registration you have for airworthiness. 

Cheers

Hello

The first thig you have to do is to make an oil anlyz (after more than 25h runing) the result with the diferntiat cylinder pressure give you the exact state of your engine, after that you know what you have to do!

Rgds

Kristof

Thanks Rotax Wizard,

can national aviation autority extend the operational life of engines  behoynd the limits when the general overhaul is due (15 years or 2.000 hours) set up by Rotax and without its permission?

Thanks for your  attention 

Franco Ralli 

Italy 

"can national aviation authority extend the operational life of engines  beyond the limits when the general overhaul is due (15 years or 2.000 hours) set up by Rotax and without its permission?"

The legal answer is yes.

No Mfg can override the legal authority of a country. If they could they could do whatever they wanted regardless of the countries regulations.

Roger is correct, however, any risk associated with doing so is solely the owners.  There is no continued airworthiness data from Rotax beyond TBO.  I know of no aviation authority that overrides this, even if they have the authority to do so.  As pointed out there is guidance by the FAA on how to decide if one wishes to extend TBO "on condition" but this requires some planning and maintaining records before hand.  It is not wise to just decide at TBO you will do an oil check and if compression is fine continue.  In my opinion this is extremely risky.  Please take the time to read the AC from the FAA on this, it was not framed for Rotax, it is a general view of how to proceed to reduce risk and follow best practice.  I am aware that in Canada, under Transport Canada, they have more detailed explanations, perhaps they have that in Europe from EASA  also.  As Roger knows experimental can do anything they like as they are generally owner maintained and not certified.  

Here is my personal opinion.  At the very least, perhaps mid engine life latest, start an annual oil analysis for trend monitoring.  Be sure to do all maintenance as called out for each check by the OEM.  Most OEM default to the Rotax data for that.  Given that many wear parts are internal and not inspected during normal maintenance intervals consider a major check at TBO.  At the very least have the gearbox completely dismantled and inspected.  Remove at least one cylinder head and cylinder with piston.  The only way to chart wear within the engine is to do a full check of the piston, piston rings, piston pin and cylinder.  Check the head for valve wear and the valve guides.  It might be an idea time to do all 4 heads for valve lap and inspection in my view.  At least this gets the highest wear items out of the way if you want to run extended hours.  Your opinions may vary and some may think this sounds excessive.  I think it is minimal.  

Cheers