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  #1  
Old 05-15-2017, 02:23 PM
Starlifter Starlifter is offline
 
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Default Performance

As a crusty old C-141 Flight Engineer I'm used to gnat's a55 performance charts which are useful and comprehensible when either flight planning or flying. I have a Superior IO-360 180hp on my 7A and, after perusing the Superior performance charts, find little useful data. Has anyone compiled data, preferably charted/graphed but tabulated would be OK, which would be useful? Specifically, demonstrated climb, cruise and descent fuel flows are what I'm looking for.
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  #2  
Old 05-16-2017, 05:47 AM
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bret bret is offline
 
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On the front page there are sample of POHs that others have shown as examples of their own aircraft, they might be close to what you are looking for but each aircraft should do all these tests in phase one and document these findings in their own POH, if they want one, not required though ...as I understand it.....
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  #3  
Old 05-16-2017, 06:17 AM
Robert Anglin Robert Anglin is offline
 
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Default Ditto for Brit.

Yes, just as Bret has said. I might add that each one of these little birds is slightly different from an other. I may have more drag with all my antennas on the outside of the skin and you may be getting 180 Hp. out of your IO-360 and mine may be putting out 202 Hp.... SO, it is always best to test your bird and make up your charts or POHB to fit your individual aircraft. As Bret has said starting with these other POHB will give you a good base format to work off of the tailor it to your needs. Hope this helps, Yours, R.E.A. III #80888

Last edited by Robert Anglin : 05-16-2017 at 06:19 AM.
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  #4  
Old 05-16-2017, 10:20 AM
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rzbill rzbill is offline
 
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Quote:
Originally Posted by Starlifter View Post
Specifically, demonstrated climb, cruise and descent fuel flows are what I'm looking for.
I think those are heavily dependent on "how" the pilot chooses to operate the powerplant. Pistons are different from turbines in this regard. More than one lever.

For instance, during climb I imagine some folks leave the mixture rich a lot longer than I do. This makes a big difference in climb fuel flow even though the throttle or 'power' setting is the same.

Same for cruise. Same throttle and RPM (same 'power' setting), but ROP vs LOP and how much?

Lastly, descent. Pilots prerogative. Reduced power descent? Cruise power descent tickling the TAS limit? Way far LOP descent? Fuel selector off descent ??

Not trying to be argumentative, just bolstering the above posts point that you may need to create these charts on your own based on how you choose to fly you bird.

One point about mixture in relation to charting fuel flow vs performance.... From peak EGT point and further lean, fuel flow controls power output directly so a chart comparing fuel flow to performance will be rational. Charting same in ROP condition has the complication of excessive fuel that can confound the data but that charting can still be useful if mixture is controlled how you want it to be and repeated when you want that performance.
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Last edited by rzbill : 05-16-2017 at 10:38 AM.
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  #5  
Old 05-17-2017, 12:50 PM
Starlifter Starlifter is offline
 
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That's what I was afraid of yet pretty much expected. Thanks for the responses. I guess I'll just have to do the charting myself. It's good to have an AP!
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  #6  
Old 05-17-2017, 12:56 PM
YellowJacket RV9 YellowJacket RV9 is offline
 
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Quote:
Originally Posted by Starlifter View Post
That's what I was afraid of yet pretty much expected. Thanks for the responses. I guess I'll just have to do the charting myself. It's good to have an AP!
Afraid of? You have an excuse to go fly! In fact, I may go do some continued 'performance testing' this evening, just to make sure nothing has changed. It's the responsible thing to do...

Also, a lot of things you will learn simply in the course of everyday flying, without having to fly a lot of complicated test profiles. Just from flying enough x-country, I know what my fuel burns are in all sorts of conditions, and a few minutes here and there of playing around can give you a good idea of different v-speeds, etc. It doesn't have to be one long, drawn out test process.

Chris
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Last edited by YellowJacket RV9 : 05-17-2017 at 01:03 PM.
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  #7  
Old 05-17-2017, 03:18 PM
BobTurner BobTurner is offline
 
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Quote:
Originally Posted by Starlifter View Post
That's what I was afraid of yet pretty much expected. Thanks for the responses. I guess I'll just have to do the charting myself. It's good to have an AP!
You don't say what's in your panel. Many modern EFIS units can record all the data. Just fly, come home and play it back on the ground. Or download it to a memory stick and take it home.
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Old 05-17-2017, 03:39 PM
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plehrke plehrke is offline
 
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Quote:
Originally Posted by Starlifter View Post
As a crusty old C-141 Flight Engineer I'm used to gnat's a55 performance charts which are useful and comprehensible when either flight planning or flying.
Do you have an example of a gnat a55 performance chart. Someone may have something similar but does not know the nomenclature.
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  #9  
Old 05-30-2017, 03:52 PM
Starlifter Starlifter is offline
 
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Originally Posted by BobTurner View Post
You don't say what's in your panel. Many modern EFIS units can record all the data. Just fly, come home and play it back on the ground. Or download it to a memory stick and take it home.
Sorry, I was away for a while. Panel is not all that modern Garmin GNS 480, Gemini PFD, TruTrak Digiflight II VS with GPSS. Nothing I've yet found gives me TAS.
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  #10  
Old 05-30-2017, 04:05 PM
Starlifter Starlifter is offline
 
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Originally Posted by plehrke View Post
Do you have an example of a gnat a55 performance chart. Someone may have something similar but does not know the nomenclature.
Sorry, was away for a while. Graphs with entry parameters, correction parameters, and results based upon those data. For example, to calculate Climbout Flight Path in nautical miles from brake release. Enter the left side of graph with desired AFL altitudego accross to Climbout Factor (calculated from another chart), go down and correct in the chart for tailwind, and exit the bottom of chart with the nautical miles from brake release.
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