Light-Sport Chronicles: Snowmobile Engine…NOT!

Kicking the Rotax myth in the head once and for all

Naw, it's got a snowmobile engine, I'm not flying one of those!" Odds are, if you've hung out a bit with experienced GA pilots, especially those who have plied the skies on personal wings for a while, you've heard that about the Rotax aircraft engine.

In case you're new to the game, a recap: Rotax, an Austrian company, is owned by Canada-based BRP (Bombardier Recreational Products). Over the last 50 years, Rotax has created more than 350 designs and built more than 7,000,000 engines! Rotaxes power snowmobiles, Sea-Doo and other watercraft, all-terrain vehicles, motorcycles and go-karts and, of course, certified S-LSA, experimental and ultralight aircraft.

So why does the "snowmobile" smackdown persist? Good question when you consider:

  • The vast majority of the 120 ASTM-approved S-LSA models use Rotax engines. Most are water-cooled four-strokes, known as the "9" series (912ULS, 914, etc.).
  • Rotax also has FAA-certified the "9" series to FAR Part 33 standards. They're standard on Diamond's HK36 Super Dimona, Tecnam's P2008 certified twin and the Stemme S10 motorglider.
  • All new "9" series engines are TBO'd (time between overhauls) at 2,000 hours.

Yet, the myth persists that an engine produced by a snowmobile maker is somehow inferior. To sort this out, I called my longtime colleague Phil Lockwood. Phil runs a thriving clutch of aviation businesses known, in aggregate, as the Lockwood Group, which offers LSA sales, service and flight training and, specifically to our question, a thriving Rotax supply, service and repair company with customers nationwide, as well as a network of Rotax service centers up and down the East Coast.


"One thing that should help dispel that myth:" Phil told me, "Rotax has now delivered more than 40,000 '9' series engines. I believe that makes it the top-selling dedicated aircraft engine in the world. It's hard to knock that level of success!"

The 912 comes in two versions: the 912ULS, which meets the ASTM design standard, and the 912S, a fully certified engine. The ULS powers most S-LSA and experimental aircraft.

"The four-stroke '9' series engines were designed from the start for aircraft," says Phil. "Once you've gone to all the trouble and testing to meet FAR 33, it's hard to call it a snowmobile engine."

Are there differences between the ASTM and certified versions?

"Very few---they are essentially the same engine, with the main difference being in the paperwork and additional traceability required for certification."

Phil, one of the most agreeable, easygoing guys in the business, has been in the game for a long time. He studied flight technology and aviation business at Florida Institute of Technology, then signed on with a leading maker of ultralights, Maxair, as Director of Sales and Marketing from 1983 to 1988.

When the company sold, he took a year off to travel and do consulting work, and fell into a relationship with Des and Jen Bartlett, who were filming a National Geographic documentary in Africa that, in time, won an Emmy. He helped them with various aspects of aerial photography; then when he heard his previous customers from Maxair were having trouble getting parts for their aircraft and Rotax engines, he contacted Ron Shettler, the North American Rotax distributor, to set up a service center in Florida.

"I wanted to take care of my old customers."

After securing the East Coast territory, he went back to Canada in 1989 to take one of the first "9" series Rotax engine schools ever given, right after the 912UL debuted. Phil's aviation acumen and timing were spot on: Before long, Lockwood Aviation had outgrown a three-car garage and then a rental hangar. He moved into the current facility he built at Sebring Airport in 1994.


"We've got seven technicians: A&P's, an IA, an aeronautical engineer and an electrical engineer. We service and overhaul Rotax aircraft engines and almost everything they're installed in, from certified to LSA to Experimental aircraft. People fly in from all over the country for service. They also ship carburetors, gear boxes and whole engines from as far away as Hawaii and Alaska."

Did he ever have doubts about Rotax?

"No," he answers. "They've always been committed to the aviation side. They're the kind of company that, once they bite into a piece of meat, they don't let go. When they got into the two-stroke snowmobile industry, there were 100 manufacturers, just like the early ultralight-aircraft days. They ended up dominating both markets; they're one of only three snowmobile engine makers now. It's the same with their Sea-Doo watercraft line, which is number one. And they're developing new aircraft engines, too. No, they're in it to stay."

Phil's flight school operates two Rotax-powered Tecnam Super Echos. "One reason was to get firsthand experience of how the engines handle the harsh high-temperature Florida environment. One engine has 1,900 hours, the other 1,800, so both are near TBO, and they'll make it without any problem. Rotax redesigned the crankcase a few years ago, just one of many improvements and refinements they've made over the last 20 years. The company is very responsive to feedback, and as a result, the engines are quite refined."

Now to the $64 million question: How does Rotax stack up to GA engines?

"I think the biggest advantage Rotax has to its nearest competitor, the Continental 0-200, is in size and weight. It's smaller and more compact. The easiest way to really see it is to compare the 82.6-cubic-inch displacement of the 912S to the 200 cubic inches of the Continental. Initially, there was a 100-pound weight difference, although Continental has whittled that down," Phil explains.

The new Lycoming 0-233 with a 213-pound dry weight and 233-cubic-inch displacement represents the traditional powerplant maker's response to the Rotax phenomenon. It's a beautiful engine and weighs 38 pounds less than the IO-235 it replaces for light-sport applications. But it's still an air-cooled engine.

"That's probably the other main advantage of a Rotax," says Phil. "With liquid cooling, we don't worry about shock cooling. And the nickel-silicone (tradename: Nikasil®) coated cylinders don't corrode. They're the same as those in my BMW, which goes 18,000 miles between oil changes and doesn't burn a drop of oil!

"In our school, the Rotax 912 runs at 5000 rpm and needs, at most, half a quart of oil at the 100-hour oil change," Phil continues. "You don't typically see that with Lycomings and Continentals: It's more common to add a quart every eight to 10 hours."

And perhaps the final nail in the "snowmobile myth" coffin: Aeroshell came out with a dedicated oil specifically formulated for the Rotax. "To me, that signified the Rotax had come of age," Phil says.

So, in other words, "Requiescat in pace (R.I.P.), snowmobile."

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