Rotax TBO for ultralights in the USA

[case106]

Does anybody know if in the USA the Rotax engines TBO is made compulsory by some sort of law?
The question refers to the Rotax non certified engines used for ultralight airplanes
Thanks
Nuccio

[Jan Olieslagers]

As stated in another thread, a Rotax (if you mean the 912/914 in their several variants) is much too heavy for a US-style ultralight. Those are 120 kg single-seaters. Delighting in more confusion: such an aeroplane is called an SSDR in the UK - the SS standing for single seat if my old memory still serves somewhat.

[case106]

As stated in another thread, a Rotax (if you mean the 912/914 in their several variants) is much too heavy for a US-style ultralight. Those are 120 kg single-seaters. Delighting in more confusion: such an aeroplane is called an SSDR in the UK - the SS standing for single seat if my old memory still serves somewhat.

Thanks!
I own a Tecnam P92 with a Rotax 912 UL.
I know this kind of airplane is sold in the US too.
I do not know in which category it is registered.
But the TBO question is still open. Here in Italy the law prescribes that the engine manufacturer TBO schedule must be respected.
I have heard that in the US this prescription is not mandatory but you can follow other means of compliance such as Reliability Centered Maintenance which is, among the other, to monitor the health of the engine with some techniques. Only when some parameters go out of tolerance then you perform the TBO; parameters are, for example, oil consumption, cylinder differential pressure, cylinder absolute pressure, etc

[Silvaire1]

I own a Tecnam P92 with a Rotax 912 UL.
I know this kind of airplane is sold in the US too.
I do not know in which category it is registered.
But the TBO question is still open. Here in Italy the law prescribes that the engine manufacturer TBO schedule must be respected.
I have heard that in the US this prescription is not mandatory but you can follow other means of compliance such as Reliability Centered Maintenance which is, among the other, to monitor the health of the engine with some techniques. Only when some parameters go out of tolerance then you perform the TBO; parameters are, for example, oil consumption, cylinder differential pressure, cylinder absolute pressure, etc

This gets a bit complicated... one step at a time.

A Tecnam P92 would be sold as an FAA Light Sport (LSA) aircraft in the US, not a conventionally FAA certified aircraft. LSAs are subject to different regulations than conventionally certified aircraft, and contrary to what you may expect LSA maintenance issues are often more problematic. One of the differences is that an LSA aircraft must be maintained in compliance with all aspects of the manufacturers maintenance manual and service bulletins. Therefore, while you understand correctly that the owner of a conventionally FAA certified engine in private service need only comply with a limited subset of manufacturer recommendations (the FAA approved Airworthiness Limitations Section of the MM, and overhaul procedures) plus FAA ADs, and can maintain the engine 'on condition' for an unlimited number of hours and/or calendar time with no special documentation, the same may not be true for an LSA engine. It depends on what the individual LSA aircraft manufacturer independently mandates in its manuals, and not on a clear FAA regulation as it would for a normally certified plane.

Some LSA owners on FAA registration are moving their aircraft to Experimental LSA (E-LSA) for this and other associated reasons, for example allowance for buying parts in the open market versus from one source only. This possibility was included in the FAA LSA regulations due to the expectation that many of the LSA manufacturers would go out of business within the life of the plane and no longer provide 'support'. Maintenance for an E-LSA is similar to that for an FAA Experimental Amateur Built aircraft, meaning even more straightforward than an FAA certified plane. So the E-LSA route makes sense for a lot of owners who use their planes only privately.

I flew a Tecnam in Italy a few years ago and was enthusiastic enough to research all this stuff. In the end it was substantially less expensive to go with an FAA certified plane but I still like Tecnams :)

[case106]

This gets a bit complicated... one step at a time.

A Tecnam P92 would be sold as an FAA Light Sport (LSA) aircraft in the US, not a conventionally FAA certified aircraft. LSAs are subject to different regulations than conventionally certified aircraft, and contrary to what might be your expectation LSA maintenance issues are often more problematic for the owner. One of the differences is that an LSA aircraft must be maintained in compliance with all aspects of the manufacturers maintenance manual and other written service bulletins. Therefore, while you understand correctly that the owner of a conventionally FAA certified engine in private service need only comply with a limited subset of manufacturer recommendations (the Airworthiness Limitations Section of the MM and overhaul procedures) plus FAA ADs, and specifically can maintain the engine 'on condition' for an unlimited number of hours and/or calendar time with no special documentation, the same may not be true for an LSA engine. It depends on what the individual LSA aircraft manufacturer recommends in its manuals.

Some LSA owners under FAA registration are moving their aircraft to Experimental LSA (E-LSA) for this and other associated reasons, for example allowance for buying parts in the open market versus from one source only. This possibility was included in the FAA LSA regulations because of the expectation that many of the manufacturers would go out of business within the life of the plane and no longer provide 'support'. Maintenance for an E-LSA is similar to that for an FAA Experimental Amateur Built aircraft, meaning even more straightforward than an FAA certified plane. So the E-LSA route makes sense for a lot of owners who use their planes only privately.

I flew a Tecnam in Italy a few years ago and was enthusiastic enough to research all this stuff. In the end it was substantially less expensive to go with an FAA certified plane but I still like Tecnams :)

that's really the clear picture I was looking for.:D
Many thanks!
:ok: