According the the manufacturer, the TBO of my engine is 2000 hours.
My understanding is that it means that an overhaul must be done after 2000 hours according the manufacturer.
The operator must prepare a maintenance programme taking into account what the manufacturer recommends.
Then the programme must be approved by the authority.
It implies that the 2000 hours is de facto mandatory, as any maintenance programme with more hours would be rejected by the authority.
What do 2000 hours mean? I could not find any definition in the documents I have. Is it engine time? Or is it engine time with power?
Is it what you log in your techlog? In that case, it’s airborne time in the UK, and block time in France and Belgium.
Can you choose in your programme another reference? For my 172(registered in France). my CAMO told me that the authority would not accept anything else than the logged block time.
If I had my plane registered in the UK, would I be allowed a TBO of 2000 hours airborne time?
It depends by the state or registration. Some states suchs as the Netherlands will allow some engine’s to be used “on condition” In that case an on condition program must be made for your engine (and components), which basically has to convince the authorities that you can have the engine safely “on condition”. In the Netherlands it does require additional maintenance before going on condition, such as oil sample, so trend monitoring is possible. It also requires a minimum ours to be flown (1 hour a month if I recall correctly) when the engine is on condition.
On condition in the Netherlands is not allowed on all engines. Other countries are free to have their own on condition regulations.
The UK and other authorities allow you to go beyond the engine TBO provided your approved maintenance program spells out the provisions for this. This is very often done as the 2000h is usually not the limiting factor but the 12 years which are equally “recommended” by the manufacturer.
Flight time is usually recorded for the engine TBO.
For my 172(registered in France). my CAMO told me that the authority would not accept anything else than the logged block time.
I would ask the CAMO for a legal reference, because this is the first time I have heard of this. Normally all aircraft maintenance (EASA-reg and N-reg) is based on airborne time. Only the pilot’s logbook is normally written up on time the aircraft is moving under its own power (i.e. brakes-off to brakes-on). If one bases maintenance on the latter basis, it makes it about 20% more expensive, for the average GA usage 
If you look closely into the MM, it usually says recommended TBO. That’s what allows the “on condition” business.
Any opinions on what % of European piston GA would be wiped out if
the 12 year limit would have a huge impact. Not many airplanes go beyond 100 hours / year when in private use, which means, they would have to be overhauled after 1200 hours. My guess is it would cause a mass exodus to registration of convenience such as N or T7 e.t.c.
If the 2000 hour limit would be rigorously enforced, it would have less impact than the 12 years, but it would still lead to people to flag out.
The question is if going N-Reg would help as EASA basically sais even today that in order to operate in European airspace airplanes need to conform to EASA rules, no matter what registration. How much that is enforced however I don’t know.
@Urs: is the T7 reg. (San Marino) outside EASA?
I’m not Piotr Szut CAMO but I will try to answer some question.
The french surveillance autority mandates an organisation named “OSAC” to supervise everything related to aircraft airwothiness / maintenance organisation. You can find the “rules” regarding aircraft maintenance on http://www.osac.aero/
Now regarding flight time logging issue, you will find the rule here
It says that BLOCK to BLOCK time must be used by GA aircraft.
Flight time may be used public air transport.
Now regarding TBO.
Usually, in France, TBO are mandatatory. See this
However, engines in general aviation aircraft can be flown beyond TBO but you have to follow some rules. Rules are here
EASA basically sais even today that in order to operate in European airspace airplanes need to conform to EASA rules
Not airplanes – only the pilots.
Airplanes yes but only “EASA complex” was proposed (18+ seats / 5700kg / ME TP / turbojet etc) but not implemented yet.
is the T7 reg. (San Marino) outside EASA?
A good question 
Do a search on e.g. “marino” here…
