The fuel-injected, fadec-equipped Rotax 912 iS, which was introduced by BRP earlier this spring, has achieved ASTM approval. What this milestone means is that LSA manufacturers can now install the engine and meet the industry’s consensus standards without the airplane being under an experimental certificate. Engines already installed will be able to get ASTM stickers as well.
The Rockwell Collins electronic control unit (ECU) in the 912 iS allows for simpler diagnostics as maintenance technicians can connect the system to a computer for analysis. And pilots have access to more accurate engine monitoring in flight. But the biggest benefit of the ECU is that it optimizes the fuel/air mixture for each altitude, which makes the engine run more efficiently.
Lockwood has installed one Rotax 912 iS on the right wing of an AirCam that is on display at the Rotax booth at AirVenture. The AirCam still has a 912 ULS installed on the left wing and Lockwood Aviation Repair’s Dean Vogel said the installation of the 912 iS was “almost plug and play.” John Hurst, the Lockwood pilot who spent 15 hours flying the AirCam from Sebring, Florida to Oshkosh, said the 912 iS runs smoother and he saw an approximate improvement in the fuel efficiency of about 15 percent compared with the ULS using the same power settings and, clearly, identical conditions.
While the Lockwood AirCam experiment appears to be the optimum way to test the engine outside a lab environment, most airplanes are likely to see greater improvements in fuel efficiency. The AirCam only allows for use of about 50 percent of the available power of the 912 iS, according to Hurst. Evektor, which has been flying the 912 iS on the Harmony LSA has seen a 21-percent lower average fuel consumption compared with the ULS. The director of Rotax Aircraft Engines, Francois Tremblay, claims the 912 iS can deliver up to 70 percent improvement in fuel efficiency compared with comparable engines.
Several manufacturers have selected the 912 iS for their LSAs, including Pipistrel, Tecnam and Flight Design. It appears the largest challenge now is for Rotax to deliver engines in a timely manner. BRP’s Christian Mundigler said the company has delivered well over 100 of the 200 engines produced to date. Flight Design expects to deliver the first CTLSi in August and Tecnam hopes to deliver their first LSAs with the 912 iS in September.
With the popularity of the new technology, BRP is pushing hard for EASA and FAA certification.