Ultralight Aircraft with Rotax 912

The 912 UL produces 80 hp from 1,211 cc and is the classic trainer and entry-level option: frugal, robust, cheaper to buy. The 912 ULS has 1,352 cc and 100 hp and is today's default choice — noticeably better take-off run, climb rate and hot-day performance, especially with two people on board. The 912 iS replaces the two carburettors with electronic fuel injection: the same 100 hp but significantly lower fuel burn, no carb heat, no carb balancing, in exchange for a higher purchase price and a dependency on the electrical system. Pilots who fly far and often recoup the surcharge through fuel over time; those who fly 40 hours a year in the circuit usually do not.

The manufacturer's recommended time between overhauls (TBO) for the 912 is 2,000 operating hours depending on variant and year, and lower for older versions. On top of that there is a calendar limit of 15 years — an engine with 400 hours built in 2005 is therefore not a bargain but an overhaul candidate. When buying used, always ask for the engine logbook, the date of the last oil change and whether the rubber parts of the drive train were replaced on schedule. A due overhaul is a five-figure item and the most common reason why two outwardly identical aircraft are priced far apart.

A UL with a Rotax 912 costs noticeably more to buy than a comparable two-stroke model — but there is no oil mixing, the intervals between overhauls are many times longer and resale value stays more stable. In practice, the 912 is the reason many ULs are still easy to sell after 20 years. If the surcharge puts you off, our price-bracket overview lists the cheaper alternatives; if you are planning long term, the four-stroke is almost always the better deal.