The Rotax 912 UL is a lightweight, reliable, and fuel-efficient aircraft engine. Introduced in the early 1990s, it is the base model of the highly successful Rotax 912 series, now used worldwide in microlights, light sport aircraft, gyroplanes, UAVs, and other light aviation applications. At its launch, the 912 UL represented a technological breakthrough by combining low weight with modern four-stroke design, offering much greater reliability and efficiency than older two-stroke engines.
The Rotax 912 UL is a four-stroke, four-cylinder boxer engine with liquid- and air-cooling, a displacement of 1211 cm³, and an output of 80 horsepower (59 kW) at 5800 RPM. It includes a reduction gearbox that optimizes propeller speed relative to engine RPM, improving efficiency and reducing noise. The engine typically features mechanical carburetors and a manual choke, in contrast to newer Rotax models equipped with electronic fuel injection.
A key advantage of the 912 UL is its low fuel consumption and fuel flexibility. Typical fuel consumption during cruise is between 13 and 16 liters per hour, making it one of the most economical engines in its power class.
The engine features dual ignition for improved safety and reliability, and its combined liquid- and air-cooling system ensures stable temperature control even under demanding conditions. The Rotax 912 UL is among the lightest four-stroke engines in its category, contributing to excellent aircraft balance and useful load.
The TBO (Time Between Overhaul) for the 912 UL is typically 2000 hours, assuming proper maintenance and fuel use. The engine is well known for its easy starting, smooth running, and low maintenance requirements, making it a favorite among homebuilders and flight schools alike.
The Rotax 912 UL has been installed in numerous aircraft, including the ICP Savannah, Flight Design CT, Pipistrel Sinus, Tecnam P92, and many experimental or kit-built airplanes. Its combination of reliability, low weight, efficiency, and mechanical simplicity has made it a benchmark in the light aviation community.
In summary, the Rotax 912 UL combines simple engineering, outstanding reliability, and minimal fuel consumption. Over decades of operation, it has proven itself as an economical, quiet, and durable engine for sport and recreational flying, forming the foundation for the global success of the Rotax 912 series.
