Features

Rotax Ups The Stakes

The new Rotax 916is promises a lot of power from a small package. Nicholas Heath finds out more.

Rotax engines are one of the most important engine manufacturers in the recreational aviation category. So, when Rotax drop a new engine, we are always interested. But this time, it’s a bit different. The new Rotax 916is looks a lot like all the Rotax family – especially the 915is. It’s a familiar horizontally opposed, liquid/air cooled engine we have come to know and love. It’s recognisable by the coloured valve covers which, on this edition, are grey/white. Well, they might be. The art department at Rotax has made all the pictures and the video kind of washed out and blue. Very creative. Kind of gloomy, but creative. So, let’s go with grey.

What I think you’re getting in a 916is is really a souped up 915is, with a longer TBO.

So, why would Rotax build this? Well, the 160hp mark is right in the sweet spot for the io320 Lycoming and the continental equivalent. Interestingly, the new engine produces a peak power of 160hp against the 915is which produces 141hp from exactly the same capacity – 1352cc. The weight gain is just 3.6 kg. I spoke to David Grigg, Manager at Bert Flood, local agents for Rotax in Australia, New Zealand, South East Asia, India and the Maldives. He is very positive about the new engine. “It has greater power, plus the 916 has a 2,000 hour TBO.” He went on to explain, “It’s still 1352 cc. The extra power comes from engine management.” I asked how long that power was available for. He said, “160 hp, at 5800 for a maximum of 5 minutes, then 137hp continuous at 5500. It’s always been like that with the Rotax engines, max 5800 for 5 minutes then cruise all day at 5500.”

When asked what type of aircraft he saw it going in to, he suggested I give Ole Hartman a call – Chief Design Engineer of Australian Aircraft Kits based in Taree, NSW, who are an approved Rotax Service Centre and produce the Hornet STOL kit aircraft. It turns out they are in the midst of developing a new transport aircraft to fit Group G (up to 760kg) which will be a bush/utility aircraft which is designed to accept the new 916is and is awaiting the new 916is to go in the prototype. Yes, you heard it here first. According to Ole, he selected the 916is because “It fits the next bracket. It’s a fine line having the power-performance matrix and it matches this airframe. You start with the engine and build an airframe around that engine. Then your performance specifications will come to fruition.” Spoken like a true engineer! I think we might have to circle back and have a look at this aircraft when Ole has it ready to fly.

The new engine produces a peak power of 160hp against the 915is which produces 141hp from exactly the same capacity – 1352cc

What I think you’re getting in a 916is is really a souped up 915is, with a longer TBO. That extra 20 odd horsepower for very little extra weight will be just the thing to kick a STOL aircraft up and in to the air. Of course, it will have applications for high speed, economical cruising at altitude for almost any airframe suited to the 912/914/915 engine, while being a pretty viable alternative to the Lycoming and Continental engines with a significant weight advantage.

Rotax engines are one of the most important engine manufacturers in the recreational aviation category.