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Another long cross country trip report


Olarry

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Flew my CTLSi sport back to Michgan from Ft Myers (978 miles) last Friday as this was the only day that a good window of weather opened up over the past week and would be for the next week to come. Other than Lakeland that was IFR early (went over the top at 6500) sky's were mostly clear all the way. Due to 10 to 20 kt headwinds, I decided to head to West Georgia Regional CTJ after LAL rather than Athens, Ga which is a more direct route by about 28 miles but lower MEA'S with the idea of staying low to minimize the headwind effect. WRONG! The ride was extremely bumpy down low forcing me to go up to altitudes of 5500 to 7500.

I requested flight following from Miami and Atlanta centers but both were to busy. This was the first Time in many years of flying several makes of aircraft, that I made such a long flight without talking to someone.

I have the dual big screen Dynons and the Garmin 796 which made it easy to navigate,avoid control areas and see traffic and weather along my route. The Dynon auto pilot performed flawlessly as I only made the one stop at CTJ for mogas. The two legs were abut four and a half hours each and my past endurance has been around three hours, so this was a long time to sit in one place but it wasn't that uncomfortable as I didn't drink much until close to destinations if you know what I mean. A lot of gadgets to play with helped the time to pass quicker. This little plane never ceases to amaze me as most look at it as a toy but in fact, it's a very capable long distance cruiser. Fuel burn averaged 5 gal hr at 52 to 5400 rpm's.

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Sounds like an excellent light sport trip. So many in aviation seem to think these 'toy' planes are limited to the local patch!

 

Interesting that you say your average fuel burn between 5200-5400 rpm is 5 gph. Just about all the 912 Sport engine (912Si)  reviewers mention 3.5 gph.

I have the 912 ULS engine and plan on 4.8gph at 5300rpm so the difference, as you post, doesn't appear to be that different.

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Thanks for the trip report.  Next time you will be in the central / north Georgia region, let me know and we can have lunch or something.  I'm based at Winder airport (KWDR).

 

Honestly, I find flying such long distances without human contact (either a passenger, another aircraft, or flight following) to be pretty boring.  I'm pretty comfortable flying distances without flight following, but I like having the chatter and listening to the radio to occupy my mind.

 

Georgia is definitely "bump central" below 4000ft during most of the year.  In the summer there is usually a well-defined haze layer, and once you get above that the air usually smooths right out.  You probably get the same thing in Florida, but I don't know if you have the haze layer to tip off where the smooth air is.   

 

What were your airspeeds?  At 5400rpm you were probably moving right along.

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Interesting that you say your average fuel burn between 5200-5400 rpm is 5 gph. Just about all the 912 Sport engine (912Si)  reviewers mention 3.5 gph.

I have the 912 ULS engine and plan on 4.8gph at 5300rpm so the difference, as you post, doesn't appear to be that different.

 

I think 3.5gph is at a closer to 5000rpm fuel burn for the iS engine, but not sure.

 

4.8gph sounds low for 5300rpm on a ULS to me, but I don't have a fuel flow gauge to tell me for sure.  I usually plan for 5.5gph at 5400rpm, though I admittedly picked that number to be on the conservative side.

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I think 3.5gph is at a closer to 5000rpm fuel burn for the iS engine, but not sure.

 

4.8gph sounds low for 5300rpm on a ULS to me, but I don't have a fuel flow gauge to tell me for sure.  I usually plan for 5.5gph at 5400rpm, though I admittedly picked that number to be on the conservative side.

You're probably right. I think there's a way to tweak the 'k-factor' (I think) so say Vans, which might provide a different reading.

 

  On the other hand going with the amount I refuel and the time flown and the amount refueled again, I've found that 4.5-5.0 seems to be the range depending on warm up time (longer in colder weather) and type of flying. Hence the 4.8 gph has been about average. I usually fly at about 5200-5300rpm.

 

  I program that into Foreflight and it will figure time and burn based on winds aloft. I've found that it's pretty accurate too.

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The CTLSi is not a toy and it is not a patch plane per se as many of the other LSAs are...  It can be cross country flyer, albeit at slower speeds 120ktas cruise.  Arguing over the effects of wind, DA, weight in flight, and whether he has the sport package all affect fuel burn rates and is a circular issue on this board.

 

His 5gph burn rate is high, esp at 5400rpm.  He may not have the sport package and he may be talking about peak burn when climbing.   In practice I have made a lot of 300nm cross country trips at 10k feet.  I run the plane at about 5350 rpm most of the time in cruise and get 130ktas ground speed in calm conditions with about a 4.2gph burn under those circumstances.  These 300nm trips take about 2hrs 45mins. and burn 10 gallons.

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You're probably right. I think there's a way to tweak the 'k-factor' (I think) so say Vans, which might provide a different reading.

 

  On the other hand going with the amount I refuel and the time flown and the amount refueled again, I've found that 4.5-5.0 seems to be the range depending on warm up time (longer in colder weather) and type of flying. Hence the 4.8 gph has been about average. I usually fly at about 5200-5300rpm.

 

  I program that into Foreflight and it will figure time and burn based on winds aloft. I've found that it's pretty accurate too.

 

Makes sense.  I will usually fly 5000-5200rpm just buzzing around, but if I'm trying to get somewhere long distance I usually go at 5300-5400.  My rule of thumb that seems accurate enough for my use is:

 

5000rpm = 4.5gph

5200rpm = 5.0gph

5400rpm = 5.5gph

 

Again, these are probably on the high (conservative) side.

 

YMMV, void where prohibited by law.

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Nice trip report. I've flown Iowa to Florida twice, Denver twice and Dallas twice, as well as all over close to home.

 

I listen to ATC (holdover from my charter days, I guess) but otherwise don't talk unless I need to or it's appropriate and also like long legs.

 

I agree, these LSAs are very practical for long distance flying in certain conditions.

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Makes sense.  I will usually fly 5000-5200rpm just buzzing around, but if I'm trying to get somewhere long distance I usually go at 5300-5400.  My rule of thumb that seems accurate enough for my use is:

 

5000rpm = 4.5gph

5200rpm = 5.0gph

5400rpm = 5.5gph

 

Again, these are probably on the high (conservative) side.

 

YMMV, void where prohibited by law.

 

   I flew my RV today locally for 1.3 hours. I began with 19 gals and ended with 13 gals. Figuring my average burn is  usually 4.5 gph - 4.8 gph ( I use 4.8 for planning) I used 6 gallons  so the flight's burn rate was 4.5 gph average for the flight. 

  I varied power from 5100 to 5400 and had 6 minutes of slow taxi to warm the oil to 120F before take-off.

 

With a 20 gal tank, and allowing 5 gals for an hour reserve I plan on 3.25 - 3.5hours range. Today at 3000 on a pretty much Standard Day I got 120-125KTAS. The wheel fairings do give about another 5kts over book speeds.

 

 On longer legs approaching the 2.5-2.75 hour point I really look at what I actually have and then make the landing for fuel decision. Totally agree with you on being conservative.

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All of these reports of a given fuel burn at a given RPM ignore prop pitch and therefore percentage of throttle.  No way the comparisons can be precise.

CT…good point. 

 

 My Skyview numbers are untweaked since the factory. I was told by Vans that I can go into the settings and tweak the 'k-factor' in order for the Skyview to DO what the engine is actually burning but to be honest in MY plane with MY prop and MY Skyview settings, I've compared actual fuel burned from the tank and used flight time and actual fuel used to come up with numbers. I've been focussed on this since I got the plane new so I'm interested in how it compares to other LSAs flying the 912ULS engine.

 

  I'm sure different drag (and prop settings) will affect individual LSA's performance. I would think the CTSW and CTLS are comparably good as far as drag, especially lacking the strut that some other high wing planes have. Most FDs seem to have wheel fairings too.

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Interesting that you say your average fuel burn between 5200-5400 rpm is 5 gph. Just about all the 912 Sport engine (912Si)  reviewers mention 3.5 gph.

I have the 912 ULS engine and plan on 4.8gph at 5300rpm so the difference, as you post, doesn't appear to be that different.

 

To see 3.5 I need to be below 5000 rpm.  I burn about 4 gph at 5000 rpm.   When you're burning premium auto fuel at $2.80 a gallon, it doesn't really matter.

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Looks like about 5 gal per hour in CTLS today, 5.7 hours total. Mostly 5200 cruise and 5400 cruise climb. Problem is sea level to 9500 east then down and up again to 8500 west for the longer over water crossings of up 76 miles. That involves a lot of 100 k cruise climb time. Winds 14 gust 28, clear skies and smooth after avoiding mountains of up to 14000 feet. Biggest challenge is class B airspace and mixed traffic.

 

Purpose of trip was to watch islands grow with red hot lava coming to surface in a couple of vents. That is happening about 200 miles from my home, as the crow flies, if we had crows, we do not. Been running some weeks now, just spectular. Must watch for tour aircraft, everywhere. Is life grand or what, when we have time to enjoy life and family!

 

Farmer

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