And for that matter, I welcome more forward-thinking aero engineers like Phil Lockwood, pictured at the bottom giving my cameras a tour of the firewall-forward Rotax 916 iS engine install in a Van’s RV-9. The RV-9 project has been quietly in the works at Lockwood’s R&D hangar in Sebring, Florida, for a couple of years and the project’s success (it’s taken a couple of tries to get right) couldn’t come at a better time because even if you don’t plan on building an RV-9 kit or yanking the Lycoming from your existing one in favor of a Rotax, I think the project sends an important message: We need more engine choices and Rotax is the one to watch for filling the void.
Long backorders and big price increases have been adding to consumer frustration across a wide sector of the piston engine market. Using the Lycoming Thunderbolt engine for experimentals as just one example, the company recently told us that buyers of new Thunderbolts should expect lead times greater than 36 months. Part of the problem is that a Thunderbolt engine is built by one or two employees. But the bigger problem that can apply to all engines—boutique, experimental or certified—is the shortage of skilled Non-destructive Inspection (NDI)/Non-destructive Testing (NDT) workers because certified NDI inspectors require hundreds of hours of logged training. This is but one of many examples of why it takes so long to get an engine.
Rotax is intriguing to me for a few reasons and much of it has to do with the tech behind the current flagship 916 iS and why it could eventually have a chance in the aftermarket and as an OEM standard. With 160 horsepower (from 83 cubic inches and weighing under 200 pounds), turbocharging and an intercooler, it has a max operating altitude of 23,000 feet, redundant electronic fuel injection and ignition and perhaps most important—an EMS (engine management system). Dual engine control units (called ECUs) sort of pilot-proof the engine to the point of a 2000-hour TBO.
Lockwood’s 916 iS/RV-9 project (the RV-9 was designed to work with lighter and smaller engines) is even more interesting because it tells a story of what a typical retrofit might look like on a wider scale. Unfortunately, it won’t exactly be easy to slap a 916 iS in a Piper Warrior, Cessna Skyhawk or anything else powered by the familiar powerplants of 1950s design. Pitch stability and effective cooling are only part of the challenge. The extended cowling on the RV-9 is proof that the Rotax had to be placed pretty far forward to get the right balance and Lockwood told me it’s now perfected, passing spin testing and given the nod by Van’s engineers. The package is nearly 90 pounds lighter than the Lycoming that’s often installed in the RV-9 and that’s a lot more useful load. “We have very efficient cooling (the 916 iS heads are liquid cooled and the cylinders are air cooled), a good CG situation, it’s lighter than a stock RV-9 with a 160-HP Lycoming and considerably faster with better takeoff and climb performance,” he told me. How fast? It’s nearly 40 knots faster than a stock RV-9, turning 190 knots at a 19,000-foot density altitude and 160 knots at 3000 feet, burning around 8.5 GPH.
See the video of the project below and look for a report on the Rotax 916 iS in an upcoming issue of Aviation Consumer.