Comment

Comment by Sebastien Heintz on November 14, 2011 at 4:05pm

The FWF kit is basically developed.  We're just waiting on the final cowl from the fiberglass shop.  I think engine lead time is several weeks.  Details, see www.ulpower.net

Comment by Joe McGough on November 12, 2011 at 11:16pm

Any idea how long before you will have the FWF kit for the 750 ready. Also, any guess on lead time. Thanks, Joe

Comment by Sebastien Heintz on November 12, 2011 at 2:58pm

In response to Steve Smith's notes we've been cruising the low-wing CH 650 with the UL350iS engine at different RPM settings to look at economy of operation.  In these next two photos we power down to 2,250 RPM, which is 100 HP according to the UL Power UL350iS engine performance chart.

At 2,250 RPM with fuel burn indicated at 4.0 GPH:

...and here indicated fuel consumption is all the way down to 2.9 GPH, though it seems to average closer to 4 GPH.  While not fast at this RPM setting (I think we could get more speed here by playing with the prop pitch), it's very economical and the aircraft handles nicely in the low nineties:

Next, we throttled up to 2,500 RPM, about 112 HP according to the chart, with fuel burn still less than 5 GPH.

We'll continue to fly the aircraft and record performance numbers, and share our photos/videos and observations, and we appreciate your comments. 

We're really enjoying this CH 650 airframe/engine combination!

Please note that the above are my observations, and not an official performance / flight test report.

Comment by Geoff Klestadt on November 8, 2011 at 6:24pm

Just wondering if the fuel flow figure is accurate and comes from a differential fuel flow meter? We aren't including the fuel return  by any chance?

Comment by Dan Watters on November 7, 2011 at 6:58pm

It is a new engine. With time I would expect the fuel burn numbers to improve a bit. What would put me off this engine is the almost $30K cost with the FWF kit. I could wait for the dollar to improve against the Euro but by then we will all be flying around in anti gravity tennis shoes.

Comment by Sebastien Heintz on November 7, 2011 at 10:34am

Gus Warren / FlyWithGus.net first flew the CH 650 with a UL260i, (which is a better comparison to the Rotax 912 series engines).  Here's his post from April 2009, Are you ready for Sun 'n Fun?, in which he reported:

Keep it light and clean and and it is better, also the fuel injection saves a bit of fuel per hp. Real world I am seeing 125 mph at less than 4.5 gph, it will do 135 about 5.3gph. Best is about 80 and 2+ gph. So, yes it does burn 3.2 per hour, and a lot more and a lot less. Have to relate GPH to speed, but even there can be great variations due to different airframes even of the same design.

We flew together that year to Oshkosh and I recall he was getting both excellent performance and efficiency with the the UL260i engine in his CH650.  That's what got us interested and enthused in UL Power...

Comment by van Cutsem Francis on November 7, 2011 at 4:32am

Hello Sebastien,

You are all speaking about the UL 350 delivering 130 HP.

A rotax 912 is given for100 hp, what about the UL260 for the 650? I suppose that the fuel burn will be less or equivalent

for a 912.

My 601XL with a 912, fuel burn is 4.7 GL at a mean speed of 120 mph

Francis.

Comment by Stephen R. Smith on November 6, 2011 at 12:08am

My hope is that the UL350iS motor is fuel efficient when operated in what I think of as “normal flying” mode.  What the motor does flat out is not too important for me because I don’t fly like that for more than the 3 to10 minutes it takes to get up off the ground or over something that is in my way.

I think the fuel burn numbers posted so far are respectable for the stated speed in a Zodiac airplane.

By way of comparison, today I flew my Jabiru-powered Zodiac at full gross for 2.8 hours.  My average fuel burn was 4.3 GPH.  Average speed was 92.9 MPH.  Average RPM was 2,386.  This for me is typical flying in my Zodiac.  Yes, it will go faster but for me the “fun meter” does not go up with speed, unless I am buzzing the field or something like that.

I love having the reserve power to pull my plane over the mountains fully loaded.  I like knowing I can take off from ANY paved airstrip in the US fully loaded on a hot day without bothering to check runway length, density altitude etc.  That’s what I want the power for.

The Jabiru is powerful, smooth and pleasant (most of the time).  I hope the UL motor is all that and also more durable than a Jabiru.  Time will tell.

Steve

Comment by Fred Wellman on November 5, 2011 at 4:04pm

PS.  A Rotax is more likely to burn about 4.5 to 5 gallons at 115 mph.  (A least according to the three RV-12s that I have flown in)

Comment by Fred Wellman on November 5, 2011 at 4:02pm

I agree with Joe.  At this point, 7.6 gph isn't terrible at 140 mph (actually I think its pretty good). I think that experimenting with a different prop can probably bring that fuel burn down a bit further.  This is exactly the info that I was looking for.  Thank you for posting it.  Now I can make an iformed decison regarding power plants.

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