If you fly a Cessna, Piper, Cirrus, or Diamond you are almost guaranteed to fly behind a Lycoming or Continental engine. These two storied engine brands have an overwhelming share of the market, but Austrian manufacturer Rotax is gaining ground, thanks to good value and modern designs.
An ideal aircraft engine is light, reliable, efficient, and works well in unforgiving environments. Rotax began by producing two-stroke engines for off-road use and slowly transitioned to motorgliders and ultralights after the company saw pilots repurposing snowmobile engines. That lineage still puts off some pilots, but the 912 ULS and 915 iS represent a better power-to-weight ratio and fuel efficiency than anything yet seen in light aircraft—in addition to offering modern features such as electronic ignition. As these engines proliferate, more mechanics are becoming comfortable working on them, and pilots are getting used to their operation. Because Rotax engines are cooled by both liquid and air, they have a radiator, and the coolant level must be verified; some require “burping” the oil reservoir by pulling the propeller through before checking the oil level; and they run at almost double the rpm of a Continental or Lycoming.
Happy owners ignore the differences in light of more useful load and a substantial fuel savings. Now that’s progress.
Engines
Piston power
Reciprocating engine types
Old school
For nostalgia you can’t beat a radial engine. The flat disc of cylinders in front harkens to an era of silk scarves and big biplanes. These beasts drink oil as if crude only costs $2.50 a barrel—which it once did.
Traditional
The classic four-cylinder horizontally opposed (the O in the name designation) training engine has been around for more than 80 years. Reliable and widespread, you may be flying the same O-320 your grandparents flew.
Modern
Rotax is one of a few modern manufacturers that is seeking to challenge our notions of what an aircraft engine can do. Rotax engines exist today mostly in Experimental aircraft or LSAs, although more certificated manufacturers are eyeing Rotax.
Related Articles
