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Post by montanapilot on May 8, 2019 14:09:11 GMT
That's good information. For me, it says that if you drop down to your fuel burn, for each hour in the air, you're only 16 miles farther than you would be if you used my number - 126 kts. In a 3 hour flight, it would take you only 24 minutes to make up for the difference in speed. However on a fairly long cross country, you would, as you note, save fuel stops, and there's no way to do a fuel stop in less than an hour. In my view, slower speeds with greater range is the way to go.
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Post by sobpilot on May 15, 2019 14:27:23 GMT
I got a chance to do some high flying and record performance numbers. This is with the Rotax 914 and a fixed pitch prop that is set for best cruse at around 5000 ft. | Alt | RPM | MP | IAS | TAS | | 9500 | 4800 | 25.1 | 86 | 102 | | 9500 | 5000 | 26.6 | 91 | 108 | | 9500 | 5100 | 27.4 | 94 | 110 | | 9500 | 5500 | 29.4 | 103 | 121 |
 Unfortunately, we don't have an accurate fuel flow instrument as part of the Astore package (I would like to add one, any help?) so by going with the POH at using manifold pressure we can get an estimate of range. It looks like 5000 RPM is a good compromise for speed and range.  POH at 4400RPM and 28in range is 7:47 hrs. Since the POH RPM is lower I'm not sure if manifold pressure alone is the determining factor on fuel burn. (I'm having problems with pictures showing up) Is there any way to imbed them without a link? |
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Post by Flocker on May 15, 2019 20:05:07 GMT
(I'm having problems with pictures showing up) Is there any way to imbed them without a link? Yes, click "Reply" on the far right-hand side and then select "Add Attachment" |
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Post by Cluemeister on May 15, 2019 22:16:43 GMT
Unfortunately, we don't have an accurate fuel flow instrument as part of the Astore package (I would like to add one, any help?) I believe Garmin offers a piece of hardware to measure fuel flow for the G3X in non-injected engines. |
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Post by LSA Flyer on May 16, 2019 2:35:14 GMT
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Post by montanapilot on May 16, 2019 20:38:37 GMT
Thanks for bringing this up. I'm going to install it. I checked with Tecnam, and as expected, I need an LOA. They e-mail the form, you fill it out and return to them, and then they send it to Italy for approval. Pain in the you-know-what, but I'm doing it.
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Post by sobpilot on May 17, 2019 13:51:05 GMT
Here is a video I recorded of my test flight. youtu.be/t2AAw7x8W-kLet me know if you think fuel burn in the POH can be used from manifold pressure alone, since most of us can't duplicate the same RPM as the book at these MP settings.  |
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Post by jetcat3 on May 18, 2019 3:07:02 GMT
I would imagine you’re burning more like 5.5 GPH at 5500 RPM as manifold is only 30”. You could pitch your prop even more so for cruise.
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Post by MarkGregor on May 19, 2019 3:40:02 GMT
Sobpilot,
At 29 inches manifold your engine is barely working. Best cruise should be around 130 true.
Mark
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Post by ChiMike on May 20, 2019 2:43:46 GMT
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Post by ChiMike on May 20, 2019 2:49:39 GMT
Friday. 9500-10,000 feet avg cruise. KRSE-KMQY
P2008 w 914. Fuel burn was 6.4 gph. 27 gallons, 4.2 hours. Pic shows 5520. Had throttle adjusted to be right at 5500 rpm.
Speed ranged from 123-127 ktas. Some bias here as I did a couple of altitude changes due to clouds which affected true avg ground speed and burned a little more fuel than I intended.
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Post by montanapilot on May 20, 2019 3:46:21 GMT
What is the device on the far left side of your panel, next to your G3X?
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Post by ChiMike on May 20, 2019 4:07:49 GMT
It is an iPhone holder
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Post by Flocker on May 20, 2019 20:14:29 GMT
Good idea. Which holder is it and how is it mounted to the panel? |
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Post by ChiMike on May 20, 2019 22:00:14 GMT
No idea which one. It’s secured with a double sided adhesion pad. I’m pretty sure I got it at a wal mart. I like going for just the high end stuff!
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