2017 Sport with Rotax 915 flight test- game changer

Philbennett

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Aug 17, 2014
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133
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London
The title gives a good account/summary but to start with some basic numbers.

With the aircraft fuelled with 30 litres, pilot weight around 80kgs meant an AUW of circa 410kgs the day was pretty much ISA being 1010Mb and around 18oC the airfield elevation of 300ft AMSL.

A caveat that data is taken with the standard instrumentation as fitted to the production aircraft we had:-

Climb performance at 60mph was 1500ft/min. Cruise speeds of 80mph saw circa 4300rpm and 15litres/hr. 100mph @ 5200rpm and 22;itres/ min.

The aircraft had a 4 blade fixed pitch prop and is the aircraft featured in this film:-


Take off performance was incredible with distance to clear 50ft of <100ft.

The raw numbers are impressive enough but the execution is even more impressive. The Rotax 915 motor absolutely makes the new Sport.

Power delivery is much more linear than a 914 and there were no vices. My expectation was that the extra power might dominate the airframe or in some way make take offs a hand full but not at all. If you pre-rotate to a usual 200rrpm then you have a short ground roll which does require a firm right boot to keep the aircraft tracking the centreline before unstick but if you pre-rotate to 300rrpm then the aircraft almost instantly unsticks and as quickly as you can bring the stick forward the aircraft is through 60mph and you're climbing away.

Indeed the extra power certainly benefits from the forward stick take off technique.

Slow flight I was down at 20mph and holding height - I ran out of time to investigate the ultimate slow speed.

I'll write some more tomorrow but essentially its a very impressive aircraft and if you fly from short strips, heavy, hot/high or all then the 915 just gives you both confidence and options. Flying light and in unchallenging conditions you just want to keep climbing out!
 
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